T640FF User Guide and Reference

T640 (M006)
Fixed function
Integrated
loop processor
Reference manual
& User guide
© 1994-1996 Eurotherm Process Automation Limited. All Rights Reserved.

No part of this document may be stored in a retrieval system, or transmitted in any form, without prior permission of the copyright holder. Eurotherm
Process Automation pursues a policy of continuous development and product improvement. The specifications in this document may therefore
be changed without notice. The information in this document is given in good faith, but is intended for guidance only. Eurotherm Process
Automation will accept no responsibility for any losses arising from errors in the document.
Issue 4 November 1996 Part Number HA 083 235 U003

ISSUE STATUS OF THIS MANUAL
Section Issue
Title page 4
Contents 4
Chapter 1 3/A
Chapter 2 4
Chapter 3 3/A
Chapter 4 3/A
Chapter 5 3/A
Chapter 6 3/A
Chapter 7 3/A
Chapter 8 3/A
Chapter 9 4
Chapter 10 3/A
Index 4
Notes
1 Sections are up-dated independently and so may be at different issues.
2 The Title page, and the manual as a whole, always take the issue number of the most
recently up-issued section.
3 Within a section, some pages in this manual may be at later issues than others. This
happens if those pages have been individually up-issued and retro-fitted into the exist-
ing manual to bring it up-to-date — a policy followed by Eurotherm Process Automa-
tion Limited to save paper and minimise harm to the environment. However, the issue
number of the whole section — as listed in the above table — is always the issue
number of the most recently up-issued page(s) in that section.
All registered and unregistered trademarks are properties of their respective holders.
T640-FF Reference Manual & User Guide HA 083 235 U003 Issue 4
Contents
Contents T640-FF REFERENCE MANUAL & USER GUIDE
Chapter 1 INTRODUCTION page

The T640 .......................................................................................... 1-1
Summary of T640-FF’s main features ........................................ 1-2
What’s in this manual ................................................................. 1-2
What’s not in this manual ........................................................... 1-3
Parameterisation tool ............................................................ 1-3
Full block-structured strategy configuration using LINtools 1-3
Getting started ............................................................................ 1-3
Chapter 2 INSTALLATION & STARTUP

Safety & EMC information .............................................................. 2-1
Installation requirements for EMC ............................................. 2-1
Installation safety requirements .................................................. 2-2
Personnel .............................................................................. 2-2
Protective earth connection .................................................. 2-2
Wiring ................................................................................... 2-3
Disconnecting device ............................................................ 2-3
Overcurrent protection .......................................................... 2-3
Installation category voltages ............................................... 2-3
Conductive pollution ............................................................ 2-3
Ventilation ............................................................................ 2-3
Electrostatic discharge handling precautions ........................ 2-4
Safety symbols marked on the unit ............................................. 2-4
Keeping the product safe ............................................................ 2-4
Misuse of equipment ............................................................ 2-4
Service and repairs ............................................................... 2-4
Cleaning instructions ............................................................ 2-4
Safe usage of alkaline manganese batteries .......................... 2-4
Alkaline manganese batteries — COSHH statement ....................... 2-5
Unpacking your T640 ....................................................................... 2-7
Handling precautions .................................................................. 2-7
Package contents ........................................................................ 2-7
T640-FF Reference Manual & User Guide HA 083 235 U003 Issue 4 Contents-1
Contents
Installation ........................................................................................ 2-8

Dimensions ................................................................................. 2-8
Panel mounting ........................................................................... 2-9
Clamp removal ........................................................................... 2-9
Removing T640 from sleeve .................................................... 2-10
Connections & wiring .................................................................... 2-10
Terminal cover removal ........................................................... 2-11
Customer terminals ................................................................... 2-11
Mains safety cover .............................................................. 2-11
Terminal designations .............................................................. 2-12
Motherboards ...................................................................... 2-12
High-level I/O boards ......................................................... 2-14
T640 zero volts schematic ........................................................ 2-16
Communications zero volts schematic ..................................... 2-16
Hardware configuration .................................................................. 2-18
Internal layout .......................................................................... 2-18
Memory module removal ......................................................... 2-18
Main fuse .................................................................................. 2-19
Switchbank 1 ............................................................................ 2-20
Switchbank 2 ............................................................................ 2-21
Serial communications jumper links & switches ...................... 2-22
Binary RS422 configuration ........................................................... 2-22
MODBUS RS422/485 configuration .............................................. 2-22
Software file types .......................................................................... 2-23
Power-up routine ............................................................................ 2-24
I/O cards ................................................................................... 2-24
Database acquisition ................................................................. 2-24
User task startup ....................................................................... 2-24
Tepid data ................................................................................. 2-27
Motherboard DIL switchbanks ................................................. 2-27
Power-up displays .......................................................................... 2-27
Normal power-up ..................................................................... 2-28
Error conditions ........................................................................ 2-28
Contents-2 T640-FF Reference Manual & User Guide HA 083 235 U003 Issue 4
Contents
Chapter 3 HANDS-ON TUTORIAL

Aims of this tutorial .......................................................................... 3-1
Hardware required for the tutorial .................................................... 3-1
Installing your T640 ......................................................................... 3-1
Connecting the power supply ..................................................... 3-1
Switch settings ................................................................................. 3-3
Removing the T640 from its sleeve ............................................ 3-3
Setting the switches .................................................................... 3-3
Strategy #1 — Single loop controller ............................................... 3-4
Power-up .......................................................................................... 3-6
Power-up messages .................................................................... 3-6
The initial display ....................................................................... 3-7
Investigating the alarm condition ..................................................... 3-7
Watchdog relay ................................................................................ 3-9
Function blocks ................................................................................ 3-9
Blocks ......................................................................................... 3-9
Fields & subfields ....................................................................... 3-9
Alarm fields .............................................................................. 3-10
Block functions ......................................................................... 3-10
PV input area ...................................................................... 3-10
PID control area .................................................................. 3-10
Control output area ............................................................. 3-11
Simulating a feedback loop ............................................................ 3-11
Displaying & altering the local setpoint ......................................... 3-11
Selecting another operating mode .................................................. 3-12
Automatic mode ....................................................................... 3-12
Manual mode ............................................................................ 3-12
Remote mode ............................................................................ 3-13
Power interruptions ........................................................................ 3-13
Warm start ................................................................................ 3-13
Cold start .................................................................................. 3-13
Tepid start ................................................................................. 3-13
Inspecting & editing the database ................................................... 3-14
Using INS ................................................................................. 3-14
Configuring ranges and limits ............................................ 3-14
Configuring absolute and deviation alarms ........................ 3-17
Contents
Configuring the decimal point ............................................ 3-17

Alarm subfields .................................................................. 3-17
Effect of the alarm settings & limits on front-panel displays ......... 3-18
Inspecting absolute and deviation alarm settings ..................... 3-18
Effect of local setpoint limit ..................................................... 3-18
Annunciation of absolute and deviation alarms ........................ 3-18
Inspecting & editing the PV input area .......................................... 3-19
Saving a database ........................................................................... 3-20
Saved databases ........................................................................ 3-20
Investigating the loop setup ‘switches’ .......................................... 3-21
Power-up/power-fail mode ....................................................... 3-21
PV fail mode ............................................................................. 3-22
On/off control ........................................................................... 3-22
Tracking of PV by the setpoint ................................................. 3-22
Pushbutton masking ................................................................. 3-23
Handling more than one control loop ............................................. 3-24
Chapter 4 USER INTERFACE

Operator displays & controls ............................................................ 4-2
Summary loop displays .............................................................. 4-2
Main loop display ....................................................................... 4-2
Tag display ........................................................................... 4-2
PV-X bargraph display ......................................................... 4-2
SP-W bargraph display ......................................................... 4-2
5-digit display ....................................................................... 4-2
Units display ......................................................................... 4-2
Output bargraph .................................................................... 4-3
Mode changes ............................................................................. 4-3
Output display ............................................................................ 4-3
Changing the output ............................................................. 4-3
Output parameters — quick access ....................................... 4-3
Setpoint display .......................................................................... 4-3
Changing the setpoint ........................................................... 4-3
Setpoint parameters — quick access .................................... 4-4
Absolute & deviation alarm settings — viewing ........................ 4-4
Absolute & deviation alarm annunciation ............................ 4-4
Contents
Database access ................................................................................ 4-4

1 Loop Access mode .......................................................... 4-4
2 Block Access mode ......................................................... 4-6
3 Field Access mode ........................................................... 4-6
4 Value Update mode, Connection Enquiry mode,
Subfield Access mode ................................. 4-6
5 Subfields .......................................................................... 4-6
Quitting database access modes ................................................. 4-6
Alarm display & inspection .............................................................. 4-7
Alarm inspection via the ALM button ........................................ 4-7
Quitting alarm inspection modes ................................................ 4-7
Security key ...................................................................................... 4-9
Key parameters ........................................................................... 4-9
Using the key .............................................................................. 4-9
Battery replacement .................................................................. 4-10
Chapter 5 FIXED-FUNCTION STRATEGIES

USING the strategies ........................................................................ 5-1
Summary of the strategies ................................................................ 5-1
Creating your own ‘fixed-function’ strategies .................................. 5-2
Running a default fixed-function strategy ........................................ 5-2
Fixed-function strategy design principles ......................................... 5-3
Fixed-function strategies —
Motherboard customer terminals ...................................................... 5-4
Strategy #1 — Single control loop ................................................... 5-5
Strategy #1 schematic ................................................................. 5-6
Strategy #1 I/O customer terminals ............................................ 5-6
Strategy #1 function blocks and parameters ............................... 5-8
Loop 1 .................................................................................. 5-8
Loop 4 ................................................................................ 5-13
One loop or two? ...................................................................... 5-14
Strategy #2 schematic ............................................................... 5-16
Strategy #2 I/O customer terminals .......................................... 5-16
Strategy #2 function blocks and parameters ............................. 5-17
Loop 1 ................................................................................ 5-17
Loop 2 ................................................................................ 5-17
Loop 4 ................................................................................ 5-21
Contents

Strategy #3 organisation ........................................................... 5-25
Master & slave .................................................................... 5-25
Blocks & connections ......................................................... 5-25
Strategy #3 — operator interface .............................................. 5-25
Strategy #4 organisation ........................................................... 5-29
Master, slave, & ratio station .............................................. 5-29
Modes ................................................................................. 5-29
Ratio bias ............................................................................ 5-29
Strategy #4 — operator interface .............................................. 5-30
Loop 1 ................................................................................ 5-32
Loop 2 ................................................................................ 5-34
Loop 3 ................................................................................ 5-36
Loop 4 ................................................................................ 5-36
Communicating on the ALIN ................................................... 5-37
Chapter 6 CHANGES LOGFILE

Logfiles ............................................................................................. 6-1
Logfile organisation ................................................................... 6-1
Logfile records ........................................................................... 6-1
Example logfile record ............................................................... 6-2
Chapter 7 INSIDE T640

Internal layout .................................................................................. 7-1
Functional blocks ............................................................................. 7-1
Motherboard ............................................................................... 7-1
Main CPU ............................................................................. 7-1
Memory ................................................................................ 7-2
Comms ports ......................................................................... 7-2
Power supplies ...................................................................... 7-3
DIL switchbanks ................................................................... 7-3
Contents
Front panel .................................................................................. 7-3

I/O sub-assemblies ..................................................................... 7-4
Customer screw terminals .......................................................... 7-4
Chapter 8 ERROR CONDITIONS & DIAGNOSTICS

Power-up displays ............................................................................ 8-1
Normal power-up ....................................................................... 8-1
Error conditions ................................................................................ 8-1
Alarm strategy .................................................................................. 8-3
Alarm priorities .......................................................................... 8-3
Alarm annunciation .................................................................... 8-4
Alarm events .............................................................................. 8-4
Alarm relay ................................................................................. 8-4
CPU watchdog ................................................................................. 8-4
Watchdog output ........................................................................ 8-4
Watchdog relay ........................................................................... 8-4
Loop fail ..................................................................................... 8-5
User alarm .................................................................................. 8-5
Main processor (CPU) fail .......................................................... 8-5
Forced manual mode .................................................................. 8-5
Chapter 9 SPECIFICATIONS
T640 base unit .................................................................................. 9-1
Panel cut-out & dimensions ........................................................ 9-1
Mechanical ................................................................................. 9-1
Environmental ............................................................................ 9-1
Front panel displays .................................................................... 9-2
Loop status summary ............................................................ 9-2
Pushbuttons .......................................................................... 9-2
Dot-matrix display character set ........................................... 9-4
Relays ......................................................................................... 9-4
Power supplies ............................................................................ 9-4
Mains version ....................................................................... 9-4
DC version ............................................................................ 9-4
T950 Security key ................................................................. 9-4
ALIN ................................................................................................. 9-4
Contents
RS422 communications .................................................................... 9-5

RS485 communications .................................................................... 9-5
BISYNC protocol ............................................................................. 9-5
MODBUS protocol .......................................................................... 9-6
Software ............................................................................................ 9-6
Maximum resources supported ................................................... 9-6
Maximum sequencing resources supported ................................ 9-7
High-level I/O .................................................................................. 9-9
Layout ........................................................................................ 9-9
T640 rear-panel customer connections ....................................... 9-9
Input ranges ................................................................................ 9-9
LIN blocks parameters not supported ....................................... 9-10
Hardware organisation .............................................................. 9-11
Analogue inputs ........................................................................ 9-11
Internal burden resistors ........................................................... 9-14
Transmitter power supplies ...................................................... 9-14
Voltage analogue outputs ......................................................... 9-14
Current analogue outputs .......................................................... 9-14
Digital inputs ............................................................................ 9-15
Digital outputs .......................................................................... 9-15
General ..................................................................................... 9-15
I/O calibration .......................................................................... 9-15
I/O circuits ................................................................................ 9-16
Chapter 10 ORDERING INFORMATION

Ordering options ............................................................................. 10-1
T640 Order codes ........................................................................... 10-1
T710 Sleeve (ordered separately) ................................................... 10-2
T950 Security key .......................................................................... 10-3
T901 Memory module (ordered separately) ................................... 10-4
Burden resistor/diode & ALIN terminator kits ............................... 10-4
INDEX
Introduction
Chapter 1 INTRODUCTION
THE T640
The T640 is the first in the range of T600 Series controllers. It is a multi-purpose 2- or 4-
loop controller with a high-speed peer-to-peer communications link and a well-established
block-structured database, allowing it to integrate tightly into a Network 6000 distributed
control system — where its full versatility and power can be realised. See Figure 1-1.
For small yet complex applications, T640’s comprehensive front-panel displays and push-
buttons mean that it can also work perfectly well on its own as a totally independent con-
troller.
NETWORK 6000 PROCESS AUTOMATION SYSTEM
OPERATOR COMMAND CONSOLES

DISTRIBUTED
WORKSTATIONS
REMOTE MULTIPLE WORKSTATIONS PRINTERS
NETWORKS
PRINTERS OTHER
VENDORS
COMPUTERS
BRIDGES
COMPUTING NETWORK
SERVER
RUGGEDISED DATABASE WORKSTATIONS
OPERATOR STATIONS SERVERS
CONTROL NETWORK
GATEWAYS
TO OTHER 1 0 0
T 6 4 0
VENDORS
EQUIPMENT 8 0
P V
6 0
LOCAL UNIT
4 0
output
CONTROLLER
2 0
R A A
M
0
P V% S P T
L
T600 INTEGRATED I NS R A
M
LOOP PROCESSOR A LM S P M
DISCRETE DCS INTELLIGENT

INSTRUMENTATION CONTROL UNIT
Figure 1-1 Network 6000 distributed control system
T640-FF Reference Manual & User Guide Issue 3/A 1-1

Introduction
Summary of T640-FF’s main features

■ Internal switch-selectable pre-configured strategies supplied in the T640’s memory
■ Easy-to-use ‘LINfiler’ file-handling package and PC Windows-based parameterisation
tool bundled with the instrument
■ Clear front-panel text, numeric, and bargraph displays, and controller pushbuttons
■ Front-panel overview of all loops, with detail of one selected loop
■ Front-panel monitor/edit access to parameter values, protected by IR security key
■ High-speed peer-to-peer communications for easy connection to the LIN via bridge
■ Serial port option for Bisync slave interface or MODBUS, or for linking internal serial
bus to external fascias and remote I/O
■ High-level I/O options
■ Removable memory module for quick unit replacement and strategy portability
■ IP65 front-panel seal, with instrument access entirely from front of panel
■ DC or universal AC mains supply options
What’s in this manual

Table 1-1 summarises the contents of the T640-FF Reference Manual & User Guide in a
concise form. Use the Table of Contents at the beginning of the manual for a more de-
tailed breakdown of what’s in the individual chapters, and/or the Index at the back to lo-
cate particular topics.
Chapter Topics
1 Introduction Summary of T640-FF features, packaging, & place in the wider network
2 Installation & startup Getting T640 going, from unpacking to power-up
3 Hands-on tutorial Practical experience in using the T640 controls, with a real strategy
4 User interface Using T640 — front-panel controls & displays explained
5 Fixed-function strategies Details of the four pre-configured control strategies supplied in ROM
6 Changes logfile How T640 records every change to a loaded database
7 Inside T640 Internal hardware, pcbs, and communications
8 Error conditions & diagnostics Error displays & diagnostic messages
9 Specifications Hardware & software specs. Resources supported. I/O circuits
10 Ordering information How to order T640 with its various options & accessories
Table 1-1 Topics covered by this manual
1-2 T640-FF Reference Manual & User Guide Issue 3/A

Introduction
What’s not in this manual

Parameterisation tool
In the fixed-function (FF) version of the T640 you do not have to create your own strate-
gies from scratch — you need only adjust certain parameter values in the databases pro-
vided, to adapt them to your particular plant control needs. This can be done directly via
T640’s front panel, and all the information required to do this is given in the present
manual. The ‘hands-on’ tutorial in Chapter 3 also gives you some practice at this.
An alternative way to parameterise fixed-function databases is to use the PC-based Fixed-
Function Parameterisation Tool (FFPT) supplied in another section of this product manual
— section 4. Software and instructions for the FFPT, and also for the file-handling pack-
age LINfiler, are given there. You will need LINfiler to be able to download/upload data-
bases to/from the T640 via an ALIN link, as well as perform several other useful filing op-
erations.
Full block-structured strategy configuration using LINtools

If you wish to go on to create and configure your own strategies — or simply adapt exist-
ing ones — for running in non fixed-function versions of the T640, you will need to refer
to the LIN Product Manual (Part No. HA 082 375 U999) for details on all the LIN-based
function blocks, their parameters and input/output connections. You will need this data to
be able to select, interconnect, and parameterise the blocks in your control strategies.
How to use the PC-based LINtools database configurator to create and download control
strategies and sequences is described in the T500 LINtools Product Manual (Part No. HA
082 377 U999).
General information on installing, commissioning and using the LIN is given in Section 2
of the product manual you are now reading, in the LIN/ALIN Installation & User Guide
(Part No. HA 082 429 U005).
Getting started
The quickest way to get going with the fixed-function version of T640 is to turn directly to
Chapter 3 and work through the ‘hands-on’ tutorial set out there. For this, all you will
need is a T640 fitted with an M006 memory module, a power supply, and a piece of wire.
If you are new to the T640, there is no substitute for actual practical experience with the
instrument — just reading about it is not the same!
The tutorial will quickly teach you how to navigate around T640’s user interface — the
front panel — and also introduce you to the simplest of the fixed-function control strate-
gies supplied in the memory module. After that, you will be ready to start customising a
selected T640 strategy to suit your plant control needs, based on the detailed information
given in Chapter 5, Fixed function strategies.

Installation & startup Safety
Chapter 2 INSTALLATION & STARTUP
This chapter presents important safety and EMC information and describes how to install,
configure, and power up the loop processor.
The main topics covered are:
■ Safety & EMC information

■ Unpacking your T640
■ Installation
■ Connections & wiring
■ Hardware configuration
■ Binary RS422 configuration
■ Modbus RS422/485 configuration
■ Software file types
■ Control strategies & sequences
■ Powerup routine
■ Powerup displays.
SAFETY & EMC INFORMATION

Please read this section before installing the processor.
This unit meets the requirements of the European Directives on Safety and EMC. How-
ever, it is the responsibility of the installer to ensure the safety and EMC compliance of
any particular installation.
Installation requirements for EMC

This unit conforms with the essential protection requirements of the EMC Directive 89/
336/EEC, amended by 93/68/EEC, by the application of a technical construction file.
This unit satisfies the emissions and immunity standards for industrial environments.
To ensure compliance with the European EMC directive certain installation precautions
are necessary as follows:
■ General guidance. For general guidance refer to the Eurotherm Process Auto-
mation EMC Installation Guide (Part No. HG 083 635 U001).
T640-FF Reference Manual & User Guide HA 083 235 U003 Issue 4 2-1
Safety Installation & startup
■ Relay outputs. When using relay or triac outputs it may be necessary to fit a fil-
ter suitable for suppressing the conducted emissions. The filter requirements will de-
pend on the type of load. For typical applications we recommend Schaffner FN321 or
FN612.
■ Use with standard mains socket. If the unit is plugged into a standard
power socket, it is likely that compliance to the commercial and light industrial emis-
sions standard is required. In this case to meet the conducted emissions requirement, a
suitable mains filter should be installed. We recommend Schaffner types FN321 and
FN612.
■ Routing of wires. To minimise the pickup of electrical noise, the low voltage
DC connections and the sensor input wiring should be routed away from high-current
power cables. Where it is impractical to do this, use shielded cables with the shield
grounded at both ends.
Installation safety requirements

This controller complies with the European Low Voltage Directive 73/23/EEC, amended
by 93/68/EEC, by the application of the safety standard EN61010-1:1993/A2:1995.
Personnel
Installation must be carried out only by authorised personnel.
Protective earth connection

NOTE. A protective earth terminal (see symbol inset), in contrast to a
functional earth terminal, is one that is bonded to conductive parts of an
equipment for safety purposes and is intended to be connected to an ex-
ternal protective earthing system.
The following safety measures should be observed:

■ Before any other power input connection is made, the protective earth terminal shall
be connected to an external protective earthing system.
■ Whenever it is likely that protection has been impaired, the unit shall be made inopera-
tive. Seek advice from the nearest manufacturer’s service centre.
■ The mains supply wiring must be terminated in such a way that, should it slip in the
cable clamp, the earth wire is the last wire to become disconnected.
WARNING!
Any interruption of the protective conductor inside the unit, or of the external pro-
tective earthing system, or disconnection of the protective earth terminal, is likely
to make the unit dangerous under some fault conditions. Intentional interruption
is prohibited.
2-2 T640-FF Reference Manual & User Guide HA 083 235 U003 Issue 4
Wiring
It is important to connect the controller in accordance with the wiring data given in this
handbook. Wiring installations must comply with all local wiring regulation. Any wiring
that is ‘Hazardous Live’ (as defined in EN61010) must be adequately anchored.
Disconnecting device
In order to comply with the requirements of safety standard EN61010, the unit shall have
one of the following as a disconnecting device, fitted within easy reach of the operator,
and labelled as the disconnecting device for the equipment:
■ A switch or circuit breaker complying with the requirements of IEC947-1 and

IEC947-3
■ A separable coupler that can be disconnected without the use of a tool
■ A separable plug, without a locking device, to mate with a socket outlet in the build-
ing.
Overcurrent protection
To protect the unit against excessive currents, the AC power supply to the unit and power
outputs must be wired through independent external fuses or circuit breakers. A minimum
of 0.5mm2 or 16awg wire is recommended. Use independent fuses for the instrument sup-
ply and each relay output. Suitable fuses are T type, (IEC 127 time-lag type) as follows;
■ Instrument supply: 85 to 264Vac, 2A, (T).

■ Relay outputs: 2A (T).
Installation category voltages

The unit should not be wired to a three phase supply with an unearthed star connection.
Under fault conditions such a supply could rise above 264Vac with respect to ground and
the unit would not be safe.
Voltage transients across the power supply connections, and between the power supply
and ground, must not exceed 2.5kV. Where occasional voltage transients over 2.5kV are
expected or measured, the power installation to both the instrument supply and load cir-
cuits should include transient limiting devices, e.g. using gas discharge tubes and metal
oxide varistors.
Conductive pollution
Electrically conductive pollution (e.g. carbon dust, water condensation) must be excluded
from the cabinet in which the unit is mounted. To ensure the atmosphere is suitable, in-
stall an air filter in the air intake of the cabinet. Where condensation is likely, for example
at low temperatures, include a thermostatically controlled heater in the cabinet.
Ventilation
Ensure that the enclosure or cabinet housing the unit provides adequate ventilation/heating
to maintain the operating temperature of the unit within the limits indicated in the Specifi-
cation (see Chapter 9).
Electrostatic discharge handling precautions
Caution
Electrostatic sensitivity. Some circuit boards inside the unit contain electro-
statically sensitive components. To avoid damage, before you remove or handle
any board ensure that you, the working area, and the board are electrostatically
grounded. Handle boards only by their edges and do not touch the connectors.
Safety symbols marked on the unit

Various safety/warning symbols are marked on the unit, which have the following mean-
ings:
Caution! Refer to Protective earth Caution! Mains

! the accompanying
documents
terminal voltages present
Alternating current Direct current
Keeping the product safe

To maintain the unit in a safe condition, observe the following instructions.
Misuse of equipment
Note that if the equipment is used in a manner not specified in this handbook or by Euro-
therm Process Automation, the protection provided by the equipment may be impaired.
Service and repairs

This unit has no user-serviceable parts. Contact your nearest Eurotherm Process Automa-
tion agent for repair.
Cleaning instructions
Use a suitable antistatic vacuum cleaner to keep the unit and all associated air inlets/out-
lets clear of dust buildup. Wipe the front panel with a damp cloth to keep it clean and the
operator legends and displays clearly visible. Mild detergents may be used to remove
grease, but do not use abrasive cleaners or aggressive organic solvents.
Safe usage of alkaline manganese batteries

The 12V alkaline manganese batteries used in the T950 security key must be stored in a
suitable manner, handled and used correctly, and disposed of safely when spent. Read the
information given in the following COSHH statement.
ALKALINE MANGANESE BATTERIES — COSHH STATEMENT

Product: 12V ALKALINE MANGANESE DIOXIDE CELLS
Part numbers: Duracell™ MN21, Panasonic™ RV08, or equivalents
HAZARDOUS INGREDIENTS
Name % by weight OSHA PEL ACGIH TLV
Potassium hydroxide (KOH) 8 2mg/m3 (C) 2mg/m3 (C)
Manganese dioxide (MnO2) 37 5mg/m3 (C) 5mg/m3 (C)
Zinc (Zn) 15 15mg/m3 (C) 10mg/m 3(C)
Carbon (C) 4 3.5mg/m3 (C) 3.5mg/m3 (C)
Steel 18 10mg/m 3(C) 10mg/m 3(C)
Brass 2 10mg/m 3(C) 10mg/m 3(C)
Mercury none added 0.05mg/m3 (C) 0.05mg/m3 (C)
PHYSICAL DATA
Property KOH MNO2 Zn
Boiling point (°C) 1320 N/A 907
Vapour pressure (mm Hg) N/A N/A 1mm @ 487°C
Vapour density (air=1) N/A N/A N/A
Solubility in water 50% 0% 0%
Specific gravity (water=1) 2.0 5.0 7.14
Melting point (°C) 360 535 420
State & colour Clear liquid Black powder Grey powder
FIRE AND EXPLOSION DATA
Flash point (method used) N/A Extinguishing media N/A
Flammable limits (LEL & PEL) N/A
Special fire-fighting procedures Fire-fighters should use self-contained breathing apparatus when
and unusual fire hazards a large number of cells are involved in a fire.
Cells may release toxic zinc fumes when exposed to fire.
HEALTH HAZARD DATA
NOTE. These compounds and metals are contained in a sealed can. Potential for exposure
should not exist unless the battery leaks, is exposed to high temperature, is swallowed, or is
mechanically, physically, or electrically abused.
Routes of entry Inhalation: YES. Skin: YES. Ingestion: YES.
Acute/chronic health hazards The most likely risk is acute exposure when a cell leaks.
Potassium hydroxide (KOH) is caustic and skin contact can
cause burns. Eye contact with KOH may cause permanent eye
injury. Potential does not exist for chronic exposure.
Carcinogenity NTP: NO. IARC Monograph: NO. OSHA Regulated: NO.
Signs/symptoms of exposure Skin and eye contact with KOH may cause chemical burns.
Medical conditions generally An acute exposure will not generally aggravate
aggravated by exposure any medical condition.
continued…
…continued
FIRST AID PROCEDURES
Skin contact If leakage from a cell contacts the skin, flush immediately with
water and cover with dry gauze.
Eye contact Flush with copious amounts of water for 15 minutes and
seek medical assistance.
Inhalation of vapour If vapour is inhaled, remove to fresh air.
REACTIVITY DATA
Stability Stable.
Conditions to avoid DO NOT heat, disassemble, or recharge.
Hazardous decomposition or byproducts When heated, cells may emit caustic vapours of KOH.
PRECAUTIONS FOR SAFE HANDLING, USE, AND DISPOSAL
Spill or leak procedures Avoid skin and eye contact. Do not inhale vapours. Neutralise
leaked material with weak acidic solution (e.g. vinegar), and/or
wash away with copious amounts of water.
Waste disposal method Dispose of spent batteries in small quantities with normal waste.
Do not accumulate, but if unavoidable, quantities of 5 gallons or
more should be disposed of in a secure landfill, as should leaking
cells, regardless of quantity. Do not incinerate batteries since
cells may explode at high temperature. Disposal should be in
accordance with all applicable national and local regulations.
Handling and storage Avoid mechanical or electrical abuse. Use neoprene, rubber, or
latex-nitrile gloves when handling leaking cells. Store at room
temperature.
Other precautions Do not attempt to recharge. Install cells in accordance with
equipment instructions. Do not dispose of in fire. Replace all
batteries in equipment at the same time. Do not mix battery
systems such as alkaline and zinc carbon in the same
equipment. Do not carry batteries loose in pocket or bag.
SPECIAL PROTECTION INFORMATION
Respiratory protection None under normal conditions.
Ventilation Subsequent to a fire, provide as much ventilation as possible.
Protective gloves Use neoprene, rubber, or latex-nitrile gloves when handling leaking cells.
Eye protection Wear safety glasses when handling leaking cells.
Other protective None.
clothing/equipment
ABBREVIATIONS USED IN THIS DOCUMENT

ACGIH American Council of Governmental Industrial Hygienists
IARC International Agency for Research on Cancer
OSHA Occupational Safety and Health Administration (US)
NTP National Toxicology Program (US)
PEL Permissible Exposure Limit
TLV Threshold Limit Values
Installation & startup
UNPACKING YOUR T640

Unpack the instrument and accessories carefully and inspect the contents for damage.
Keep the original packing materials in case re-shipment is required. If there is evidence of
shipping damage, please notify Eurotherm Process Automation or the carrier within 72
hours and retain the packaging for inspection by the manufacturer’s and/or carrier’s repre-
sentative.
Handling precautions
Caution
Electrostatic sensitivity. Some circuit boards inside the T640 contain electro-
statically sensitive components. To avoid damage, before you remove or handle
any board ensure that you, the working area, and the board are electrostatically
Package contents
Check the package contents against your order codes, using the labels on the components
to help you. Product labelling includes:
■ Outer packaging label. Shows the full instrument order code, instrument serial
number, hardware build level, and software issue number.
■ Antistatic bag label. Shows the full instrument order code, instrument serial number,
and hardware build level.
■ Sleeve labels. Two labels, one outside and one inside showing the sleeve order code
and sales order number.
■ Instrument label. One on the instrument, identical to the antistatic bag label.
■ Memory module label. One label showing the software issue number.
■ Security key label. Shows access, area, and ID code.
Dimensions Installation & startup
INSTALLATION
Dimensions
Figure 2-1 shows the DIN-size aperture needed for panel-mounting the T640. Also shown
are the unit’s overall dimensions, the mounting clamps, panel section, terminal cover and
screw, and the access for cabling.
Panel aperture
mm
DIN
138 – 0
+1
43700 Terminal cover Terminal screw
67.5
68 +0.7
–0
72 10.6 258
137.4
144
Panel section 1.5 - 25 Mounting clamp Cable access
Figure 2-1 T640 principal dimensions
Installation & startup Panel mounting
Panel mounting
Insert the sleeve in the aperture and fit the two clamps as shown in Figure 2-2. To fit a
clamp, position it flat on the sleeve, locating the hook in the slot. Slide the clamp away
from the panel to engage the hook firmly, and snap the two feet into the two small re-
cesses. Screw the clamp rod in to hold the sleeve lightly in position. Fit the second clamp
in the same way. Finally, tighten up both clamps to exert a moderate retaining force. To
avoid panel distortion, do not overtighten. The maximum recommended torque is 0.6Nm.
Feet
Hook
Figure 2-2 Fitting a clamp to the sleeve
Clamp removal
See Figure 2-3. Slacken off the clamp by at least 2mm and insert a screwdriver blade be-
tween the feet at the end of the clamp body. Lift the screwdriver handle to lever the clamp
towards the panel and disengage it. Do not press downwards — this could cause dam-
age!
LIFT!
Figure 2-3 Removing a clamp from the sleeve
Connections & wiring Installation & startup
Removing T640 from sleeve

Withdrawing the T640 from its sleeve is done entirely from the front of the mounting
panel, without disturbing any of the system wiring.
Caution
Repeated removal/replacement of the T640 under power erodes the connectors.
Anti-static precautions must be observed when handling the unit out of its sleeve.
See Figure 2-4. To unlock the T640 insert a small screwdriver blade into the slot in the
retaining clip at the bottom of the fascia and slide the clip to the left as far as it will go.
Repeat this for the clip at the top of the fascia, but slide it to the right. To withdraw the
unit use the extractor tool supplied in the accessory kit (Part No. BD 082253). Hold the
tool at an angle of about 45°, insert the hook into the opening under the ‘SP-W’ pushbut-
ton, then level the tool and pull the unit from the sleeve. Remember to lock both retaining
clips after refitting the unit in the sleeve.
INS R A
??
ALM SP-W M
Extractor tool Slot in Opening

retaining clip
Figure 2-4 Withdrawing T640 from the sleeve
CONNECTIONS & WIRING

Electrical connections to the T640 are made via three blocks of customer screw terminals
at the rear of the sleeve, protected by a terminal cover. Wiring passes through the opening
in the base of the terminal cover. All connections are low current and a 16/0.20 cable size
is adequate. The maximum cable size for these terminals is 2.5mm2. ‘Bootlace’ type fer-
rules are strongly recommended.
Power input. The instrument supply should be fused externally in accordance with
local wiring regulations. The mains option accepts 90 - 265 Vac, 45 - 65 Hz, the DC op-
tion 19 - 55 Vdc. Power input depends on the application and configuration, and on the
I/O cards fitted, but is a nominal maximum of 25VA per T640. Please refer to Chapter 9,
Specifications, for further details.
Installation & startup Customer terminals
Terminal cover removal

See Figure 2-5. With the sleeve upright unscrew the retaining screw and pull the cover
away from the cover bracket and cable clamp assembly. To remove the bracket, lift it to
free the hooks from the tabs, then withdraw it from the sleeve. Refitting the bracket and
cover is the reverse procedure.
Hooks
Retaining
screw
Cable clamp
Cover Cover bracket Tab
Figure 2-5 Removing the terminal cover
Customer terminals
Figure 2-6 shows the customer terminals (example). Other configurations are possible de-
pending on the I/O and power supply ordered. The Figure shows the MAINS option
motherboard terminal block with safety cover, and Site 1 I/O and Site 2 I/O terminal
blocks. Wire connectors, securing screws, and terminal identification labels are also
shown. Connect a good local earth to the M4 screw terminal. Do not connect an external
earth directly to terminals 1 and 2.
Mains safety cover

This fits over the mains screw terminals to prevent accidental contact with the live screws.
To remove the cover loosen the two screws and pull it off. To replace the cover insert its
two legs fully into the corresponding terminals and tighten up the screws securely.
Customer terminals Installation & startup
Internal earth GND

Earth screw
connection 1A terminal
2A
wires 1B (M4)
2B
1C
2C 1
1D
2D 2
1E
2E
1F
2F LL Safety cover
1G
2G NN screws
1H
2H
1J
2J
1K
2K
1L
2L
1M
2M
1N
2N 11
1P
2P 12
1Q
2Q 13
1R
2R 14 Safety cover
1S
2S 15
1T
2T 16
1U
2U 17
1V
2V 18
1W
2W 19
1X
2X 20
1Y
2Y 21
1Z
2Z 22
MAINS option
Site 2 I/O Site 1 I/O motherboard ter-
terminals terminals minal block
Figure 2-6 Customer terminals (example)
Terminal designations
Motherboards
Table 2-1 shows the terminal designations for two motherboard terminal block options,
with the ac MAINS option on the left and the DC option on the right of the table.
The uses of these terminals and how they connect to T640’s internal circuitry are de-
scribed in later sections.
Installation & startup Customer terminals
GND GND
Earth screw terminal (M4) Earth screw terminal (M4)
1 Internal earth* 1 Internal earth*

2 Internal earth* 2 Internal earth*
L Mains live
N Mains neutral
7 DC input 1 +
8 DC input 1 –
9 DC input 2 +
10 DC input 2 –
11 RS422 TX+ 11 RS422 TX+
12 RS422 TX– 12 RS422 TX–
13 RS422 & RS485 Gnd 13 RS422 & RS485 Gnd
14 RS422 RX+ & RS485 + 14 RS422 RX+ & RS485 +
15 RS422 RX– & RS485 – 15 RS422 RX– & RS485 –
16 Watchdog/User relay 16 Watchdog/User relay
17 OPEN = fail 17 OPEN = fail
18 Alarm relay 18 Alarm relay

19 OPEN = fail 19 OPEN = fail
20 ALIN Ground 20 ALIN Ground

21 ALIN phase A 21 ALIN phase A
22 ALIN phase B 22 ALIN phase B
*Factory-connected externally
Table 2-1 Customer terminals for AC (left) & DC (right) T640 motherboard options
Customer terminals Installation & startup
High-level I/O boards

Table 2-2 shows terminal designations for the high-level I/O board options, fitted in sites 1
(right) and 2 (left). Note that Site 1 terminals are labelled 1Ato 1Z, and Site 2 terminals
are 2A to 2Z. Also shown are the software ‘function blocks’ in the control database that
link to each terminal or set of terminals, and the required value of their output/input type
parameters. (You are introduced to function blocks in the tutorial in Chapter 3.)
Terminal ( iteNo
S =2) Linked block Terminal ( iteNo
S =1) Linked block
2A Current out AN_OUT 1A Current out AN_OUT
Chann Chann
2B Current ou OutType= mA 1B Current ou OutType= mA
2C TX power su 1C TX power su
2D TX power s 1D TX power s
2E Analogue Chann AN_IP:
InType= Vol 1E Analogue Chann AN_IP:
InType= Vol
2F Analogue Chann AN_IP:

InType= Vol 1F Analogue Chann AN_IP:
InType= Vol
2G Analogue g 1G Analogue g
2H Analogue Chann AN_IP:
InType= Vol 1H Analogue Chann AN_IP:
InType= Vol
2J Analogue Chann AN_IP:

InType= Vol 1J Analogue Chann AN_IP:
InType= Vol
2K Analogue g 1K Analogue g
2L OutType= Volt 1L
Analogue o Chann AN_OUT: Analogue o Chann AN_OUT:
OutType= Volt
2M Analogue o Chann AN_OUT:

OutType= Volt 1M Analogue o Chann AN_OUT:
OutType= Volt
2N Analogue g 1N Analogue g
2P Digital i Bit 1P Digital i Bit
2Q Digital i Bit 1Q Digital i Bit
DG_IN:
InType= Vol DG_IN:
InType= Vol
2R Digital i Bit 1R Digital i Bit
2S Digital i Bit 1S Digital i Bit
2T Digital ou Bit 1T Digital ou Bit
DG_OUT, DGPU
2U Digital ou Bit 1U Digital ou Bit
2V Digital ou Bit DG_OUT 1V Digital ou Bit N.B. In DGPULS
Bit0 - Bit3 corres
2W Digital ou Bit 1W Digital ou Bit Chan1-Chan4,resp
2X (Not connect 1X *Pullup: 15V out O
2Y Digital gr 1Y Digital gr
2Z Digital gr 1Z Digital gr
NB. SiteNo, Channel, & Bit numbers refer to the associated I/O function block’s corresponding parameters
*Pullup connects internally to digital outputs of both sites
Table 2-2 Customer terminals for high-level I/O options — Site 2 (left) & Site 1 (right)
Installation & startup Zero volt schematics
Power supply bus

L
PSU PSU +5V
Main I/O Front
N CPU boards panel
RS422/
485
GND
13
0V
1 RS422/485
2 PSU
Instrument case
Figure 2-7 T640 internal zero volts & power supplies schematic
External ISB
zero volts
reference I/O
bar control
Non- circuit Non-
isolated isolated
analogue analogue
inputs outputs
Analogue
GND I/O
terminals PSU
0V
Non- Non-
isolated isolated
digital digital
inputs outputs
Digital
GND
terminals
20
13
External zero
volts power
bar
Figure 2-8 T640 I/O zero volts & power supplies schematic
Zero volt schematics Installation & startup
T640 zero volts schematic

Figure 2-7 shows schematically T640’s internal zero volts and power supply arrange-
ments, and associated customer screw terminals. The power supply units feed the main
CPU, I/O board(s), front panel, and RS422/485 power supply unit, via a power supply bus.
The GND terminal connects directly to the instrument case, and via wires to terminals 1
and 2, which must not be connected to externally.
I/O zero volts schematic

Figure 2-8 shows the (generalised) I/O zero volts and power supply arrangements, and as-
sociated customer screw terminals. The number and designations of terminals associated
with the non-isolated analogue inputs and outputs depend on what I/O options are fitted
(Table 2-2 shows those currently available). The I/O control circuit communicates via the
ISB (Internal Serial Bus). Connect the analogue ground terminal(s) to an external zero
volts reference bar as shown.
The number and designations of terminals associated with the non-isolated digital inputs
and digital outputs also vary with I/O option. Connect the digital ground(s) to an external
zero volts power bar, which should be connected to a clean instrument earth.
Communications zero volts schematic

Figure 2-9 shows the RS422/485 and ALIN comms connections with associated customer
screw terminals. The main CPU is opto-isolated from the RS422/485 transmit/receive ter-
minals. Factory-set jumpers (J4, J5, and others not shown) configure the motherboard for
RS422, RS485, or external ISB (Internal Serial Bus) operation. See next section.
NOTE. The ALIN cable screen and the RS422/485 cable screen should each be
grounded at one point only.
Installation & startup Zero volt schematics
+5V
J5 422/485
14 – 422/485 J4
Main
CPU
15 + EXISB EXISB
13
RS422/RS485 +5V
ground TX+
– 11
Terminal func-
tions depend 12
on SW1 set-
tings TX–
RS422/485
ALIN
phase A 21
Main
CPU
ALIN
phase B 22
ALIN interface
ALIN circuitry
ground 20
ALIN
Figure 2-9 T640 communications zero volts schematic
Hardware configuration Installation & startup
HARDWARE CONFIGURATION
Internal layout
Figure 2-10 shows T640’s internal layout (example). The motherboard is the main elec-
tronics board on which all I/O board options are mounted. It carries two configuration
DIL switchbanks 1 and 2, and the memory module in its socket. The figure shows an I/O
board in Site 1, and an expansion-type I/O board in Site 2. Other I/O options and arrange-
ments are possible, depending what was ordered.
Memory module removal

See Figure 2-10. Use a screwdriver blade to slide the retaining clip towards the front
panel as far as it will go, then pull the module out of its socket. Replacement is the re-
verse procedure.
Caution
The module can be pushed fully home only if it is the right way round.
Check this before applying excessive force, which can damage the pins.
Retaining Memory I/O expansion

clip module board
Front
panel
1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8
ON ON
Memory
module DIL DIL Site 1
socket switchbank 1 switchbank 2 Motherboard I/O board
Figure 2-10 T640 internal layout (example)
Installation & startup Main fuse
Main fuse
See Figure 2-11. The motherboard carries the T640 main fuseholder. The fuse is a
20 × 5 mm 250Vac antisurge cartridge fuse rated at 500mA (AC option), or 2A (DC op-
tion). Unscrew the fuse cap anticlockwise to remove.
Daughter
1
board
J2 2
J6 J5
321 3 21
Jumper links
(note polarity)
Main fuse-
holder 12 3
J4
Figure 2-11 T640 motherboard showing fuse & jumper locations
Switchbank 1 Installation & startup
Switchbank 1
Figure 2-12 shows the location and functions of the eight switches in DIL switchbank 1.
1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8
ON ON
Comms selection
(see Table 2-4)
on-value
1 2 4 OFF
SW1
1 2 3 4 5 6 7 8 ON
Cold start enable Strategy selection
Warm start enable

Enable loop/database watchdog
3 4 Action at startup*
ON ON Warm start if possible, else cold start if possible, else idle
ON OFF Cold start if possible, else idle
OFF ON Warm start if possible, else idle
OFF OFF Idle
*See Table 2-5 for a more detailed summary
Figure 2-12 SW1 location and functions
■ Switches 1 and 2, together with four jumper links, configure the type of communica-
tions used by the T640 via its serial port. See Table 2-3 below in the section Serial
communications jumper links & switches. These switches and links are set at the fac-
tory according to the comms option ordered and should generally be left as supplied.
Installation & startup Switchbank 2
■ Switches 3 and 4 configure the way the T640 powers up, and are usually both set to
ON for normal operation. T640’s power-up routine is explained in detail later in the
section Power-up routine.
■ Switch 5, when set to ON, causes the watchdog relay contacts — customer terminals
16 & 17 — to open if a loop (user task) stops running or if the database halts. This
function is in addition to the relay’s normal actions, i.e. CPU failure watchdog (closed
= healthy, open = failure), and user alarm (via the T600 block’s UsrAlm field). With
switch 5 OFF, the relay does not respond to loop or database halts.
■ Switches 6, 7, and 8 select the number of a preconfigured fixed-function strategy to be
loaded to RAM and if possible run in the T640. The strategy selected is the sum of the
‘values’ of the three switches (OFF = 0, ON = ‘value’ as shown in Figure 2-12). E.g.
strategy #3 has been selected in the figure. Setting these three switches all OFF pre-
vents any standard strategy being loaded. Running standard strategies is explained in
Chapter 5, Fixed function strategies.
Switchbank 2
Figure 2-13 shows the ALIN address DIL switchbank 2, and an example setup (7A hex).
1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8
ON ON
SW2 (ALIN Address)

OFF=0
hex
7 A address
ON=1
1 2 3 4 5 6 7 8 binary
0 1 1 1 1 0 1 0 address
0 1 0 1 1 1 1 0
BINARY HEX
0 0 0 0 0
0 0 0 1 1
0 0 1 0 2
0 0 1 1 3
0 1 0 0 4
0 1 0 1 5
0 1 1 0 6
0 1 1 1 7
1 0 0 0 8
1 0 0 1 9
1 0 1 0 A
1 0 1 1 B
1 1 0 0 C
1 1 0 1 D
1 1 1 0 E
NOTE. Addresses 00 and FF are reserved and must not be used. 1 1 1 1 F
Figure 2-13 SW2 — ALIN address setup (example)
MODBUS configuration Installation & startup
This bank of switches is used to set up the address of the T640 on the ALIN. Figure 2-13
shows how to set them up and read them, using the hexadecimal address 7A as an exam-
ple. Note that switch 1 is the least significant bit, and switch 8 the most significant, i.e.
they are in ‘reverse order’. Note also that addresses 00 and FF must not be used.
Serial communications jumper links & switches

Four jumper links (J2, J4, J5, and J6), together with switches 1 and 2 of Switchbank 1, are
factory-set to configure the motherboard according to what serial comms option was or-
dered. You can check that these are set as required — the jumpers and switches are lo-
cated on the motherboard where shown in Figure 2-11. Table 2-3 shows the switch set-
tings and jumper links for the five possible comms options.
Required DIL switch Jumper links

comms option SW1/1 SW1/2 J2 J4 J5 J6
Binary RS422 OFF OFF Not fitted 2-3 2-3 2-3
Modbus RS422 ON OFF Not fitted 2-3 2-3 2-3
Modbus RS485 ON OFF 1-2 2-3 2-3 2-3
External ISB (RS422)* Don’t care ON Not fitted 1-2 1-2 1-2
External ISB (RS485)* Don’t care ON 1-2 1-2 1-2 1-2
*Not implemented at current issue
Table 2-3 Comms option switch & jumper link settings
BINARY RS422 CONFIGURATION

Table 2-3 shows the hardware settings required for communication via an RS422 serial
link using binary (BISYNC) protocol.
Each T640 fixed-function strategy database has an S6000 category function block running
in it, allowing it to emulate a TCS System 6000 instrument, or to be supervised by a
T1000 or other suitable instrument over the serial link. Addresses (instrument numbers, 0-
127) are allocated via the S6000 block’s Instr_No parameter, and baud rates via the T600
header block’s BinSpd1 and BinSpd2 parameters.
Chapter 5, Fixed function strategies, explains how to set up these parameters.
MODBUS RS422/485 CONFIGURATION

To configure the hardware for MODBUS comms, set up the motherboard switches and
jumper links as shown in Table 2-3. Note that jumper link J2 determines the medium used
— RS422 or RS485.
A MODBUS configuration — ‘gateway file’ — must be created and downloaded to the
T640 to run alongside the regular LIN control database. This gateway file (.GWF
filename extension) defines the communication between the LIN database (.DBF file) and
Installation & startup Software file types
the MODBUS device(s) connected to the T640 via the serial link. The MODBUS con-
figuration also specifies slave/master status, slave address, comms data rate and parity/
stop bits.
Using the LINtools MODBUS configurator is fully described in the T500 LINtools Prod-
uct Manual (Part No. HA 082 377 U999), together with general information on MOD-
BUS.
SOFTWARE FILE TYPES

Table 2-4 lists the different file types that are found in the T640’s EEPROM and EPROM
(ROM) memory areas, that you may see via the LINfiler package. Some of these files are
supplied already installed — those marked with * in the table. Others appear automati-
cally when you use the instrument, or may be downloaded from a PC. EEPROM and
ROM reside in a removable memory module, which allows a new strategy to be plugged
directly into an existing controller, or conversely allows a strategy to remain if the control-
ler must be changed. (Accessing and replacing the memory module was described earlier
in this chapter, in the section Hardware configuration. T640’s internal architecture is de-
scribed in Chapter 7, Inside T640.) Further details on these files are given in the relevant
sections of this manual.
Filename Extension File type

Control strategy name .DBF Control strategy database (parameters, connections, etc.)
Control strategy name .RUN T640 coldstart filename (i.e. last database run)
Control strategy name .GWF MODBUS configuration file (‘GateWay File’)
Sequence name .SDB Sequence database
System filename .LIB *Library of system routines in ROM area
Factory-set filename .FFn *Fixed-function strategy in compressed format (n = 1-4)
Control strategy name (current) .TPD Tepid data file
Control strategy name .Lnn Logfile of database changes via the INS pushbutton (nn = 01 - 99)
Language name .LNG Non-English language front-panel messages
Table 2-4 T640 file types
Power-up routine Installation & startup
POWER-UP ROUTINE
This section outlines what happens when a T640 powers up and how its final state is ar-
rived at. You do not not generally need to understand the power-up process fully to use a
T640, but a general conception of what occurs is useful — especially if something goes
wrong.
I/O cards
I/O cards power up with their outputs ‘killed’ (i.e. tri-stated or low, depending on the par-
ticular card). The T640 ISB (internal serial bus) starts before the user tasks start, although
initially the I/O card outputs are not written to, and hence remain in their killed state.
Database acquisition
The database is acquired in a manner depending on the type of startup:
■ If a warm start occurs the database is the one in RAM, provided it is uncorrupted. If it
is corrupted, the last-loaded database file (.RUN, stored in EEPROM), overlaid with
‘tepid data’, is used. Please refer to the section below for more details on tepid data.
■ If a cold start occurs the database is loaded from EEPROM
■ Otherwise, the database is loaded from one of the standard pre-configured strategies
■ If no valid source is found, a null database is created.
Figure 2-14 charts the events that occur when T640 is powered up. Figure 2-15 shows the
warm start routine that may be called during power-up, and should be read in conjunction
with Figure 2-14. As there is no hardware realtime clock in the T640, it must derive
elapsed time since power-down (needed in the warm start routine) from a clock it main-
tains over the peer-to-peer communications. If this is not possible, power-up follows the
alternative route shown in Figure 2-15. After loading, the entire database is subjected to a
sumcheck test.
User task startup

Before user tasks (‘loops’) start, the output blocks execute their power-up defaults, as de-
fined by their OPTIONS/PwrFlLo parameters, or in the case of a cold start, as specified by
the strategy. This is needed to ensure that the InitDmnd value (in the MAN_STAT block)
is itself initialised, and causes the real plant outputs to attain their power up states. Output
blocks with sumcheck errors do not execute at all; hence their outputs remain ‘killed’.
The loops now start executing. The MODE block selects manual mode — if ManPwrUp
is TRUE — and the manual station initialises the Demand parameter.
Installation & startup Power-up routine
POWER-UP
Standard
Yes
strategy
selected?
No Yes .RUN file match

selected .PKn
file?
Database in No No
RAM?
Yes
Warm Start No
SW1/4 ‘ON’?
Yes
GOTO
Warm Start routine
(see Figure 2-15)
Yes
Success?
No
Cold Start No
SW1/3 ‘ON’?
Yes
Yes Standard No
strategy
selected?
Scan EEPROM then
Find unique .RUN
ROM for chosen .PKn
file & copy .DBF
file. Copy .DBF name
name from it
from it
No
Success?
Yes
Search EEPROM
for .DBF file &
load it to RAM
Yes Successful
.DBF file load?
No
Standard No
strategy
selected?
Yes
Unpack .PKn file
and load to RAM
RUN DATABASE NULL DATABASE
Figure 2-14 T640 power-up routine
Warm start routine Installation & startup
WARM START
Does
EEPROM .RUN filename No
match RAM database
filename (memory module
changed)?
Yes
Yes
RAM OK?
No
Get .DBF file that
matches .RUN
file (EEPROM)
Yes
Success?
No Overlay
‘Tepid Data’
RETURN FAIL
T600 block’s Yes

ColdStrt = 0?
No
Derive time
elapsed since
power-down
Yes No
Success?
No Cold Start Yes

Cold Start
SW1/3 ‘ON’? SW1/3 ‘ON’?
Yes
No
No RETURN FAIL
Cold Start time
Flag Brownout
exceeded?
No Brownout time Yes

exceeded?
RETURN FAIL
RETURN SUCCESS
Yes
Flag Brownout
RETURN SUCCESS
Figure 2-15 T640 warm start routine (& see Figure 2-14)
Installation & startup Power-up displays
Tepid data
At the end of each task iteration a package of data is assembled in a .TPD file in RAM,
ready to be written to EEPROM should a power-down occur. This data — ‘tepid data’ —
includes each loop’s local setpoint (SL), output (OP), and operating mode (MODE). In
the event of a power-down, there is enough time for the tepid data in the .TPD file to be
transferred rapidly to EEPROM, ready to be used if required during a subsequent warm
start routine (see Figure 2-15).
Motherboard DIL switchbanks

DIL switchbank SW1, switches 3 and 4, determine how T640 starts up after a power inter-
ruption — as charted in Figures 2-14 and 2-15. For normal T640 operation both switches
should be ‘ON’ to provide full warm start and cold start capability.
The location of SW1 was shown in Figure 2-12, and the functions of switches 3 and 4
briefly summarised. Table 2-5 below provides more detail on the effect of the four possi-
ble switch setting combinations.
Sw 3 Sw 4 T640 power-up routine & final state

OFF OFF T640 idle; database not loaded.
OFF ON Do warm start, i.e. checksum database in memory. If OK, run database from where it stopped.
If corrupted, try tepid start, i.e. get .RUN file if possible, overlay tepid data and run database.
If tepid start fails, clear memory and idle without running database.
ON OFF Do cold start, i.e.: count xxx.RUN files. If exactly one exists, try to load and run xxx.DBF.
If this fails, or unique xxx.RUN file does not exist, idle without running database.
ON ON Power interruption < ColdStrt: do warm or tepid start. If this fails, do cold start (as above).
Power interruption ≥ ColdStrt: do cold start
Table 2-5 T640 switchbank SW1, switches 3 & 4 functions
POWER-UP DISPLAYS
This section describes the messages normally displayed on T640’s front panel during
power-up. For full details of all the front-panel displays and controls, refer to Chapter 4,
User interface. The hands-on tutorial presented in Chapter 3 also familiarises you with
the front panel power-up messages.
Power-up displays Installation & startup
Tag display ε T640

10
Units display
80
PV-X
5-digit display
60
Output bargraph
OUT-Y
40
PV bargraph
SP bargraph
20
Deviation bargraphs
Mode letter
0%
‘Displayed loop’ PV-X SP

arrowhead
INS R A
??
Pushbuttons
ALM SP-W M
Figure 2-16 T640 front panel — principal features
Normal power-up
Figure 2-16 shows the principal features of T640’s front panel.
A Power-on Reset message normally flashes briefly in the red tag display when T640 is
powered up, while the front panel awaits communications from the main CPU. Then,
WarmStrt Trying, TepidSrt Trying, or ColdStrt Trying, flash to tell you the type of
startup procedure T640 is attempting. If a fixed-function strategy is being loaded for the
very first time, Un Pack DataBase flashes in the tag display as the .FFn file is being de-
compressed. Finally, the fascia adopts the normal display as described in Chapter 4.
Error conditions
A number of error conditions can arise during the power-up process, which are reported
on the front-panel displays as messages or error codes. These are described in Chapter 8,
Error conditions & diagnostics. Please refer there for details.
Tutorial
Chapter 3 HANDS-ON TUTORIAL
AIMS OF THIS TUTORIAL

This tutorial will give you ‘hands-on’ experience of the T640, and at the same time ac-
quaint you with the simplest of the four in-built ‘fixed-function’ control strategies sup-
plied in ROM. This is #1, a single control loop. The other three fixed-function strategies
are all designed around this loop, so what you learn here can be applied to configuring
them as well, via T640’s front-panel pushbuttons and displays.
Note that in this tutorial the T640 operates as a stand-alone instrument — no network or
communications are involved.
Much of the information given here can also be found in other parts of this manual. Refer
there if you need more comprehensive information.
HARDWARE REQUIRED FOR THE TUTORIAL

■ T640 fixed function instrument — fitted with the M006 option memory module.
■ Short wire link, terminated (ideally) with bootlace ferrules.
■ Terminal screwdriver.
■ Digital multimeter (optional).
■ An appropriate power supply — DC: 19-55V (25W), MAINS: 90-265Vac, 45-65Hz.
INSTALLING YOUR T640

If you have not already done so, please refer to Chapter 2, Installation & startup, for de-
tails on unpacking your T640.
Note that for this tutorial there is no need to panel-mount the instrument — it can simply
rest on a bench in its sleeve, with the rear terminal cover removed.
Connecting the power supply

Remove the terminal cover and cable clamp from the rear of the T640 to access the cus-
tomer terminals. Figure 3-1 shows the cover and clamp.
First determine which option you have — DC or AC mains. You can see this from Figure
3-2 and also from the order code label on the sleeve (the second field is DC or MAINS,
respectively).
With the power switched off, wire the power supply to the terminals shown in the figure,
according to your option. Do not power up yet!
Tutorial
Figure 3-1 Terminal cover removal
Mains EARTH 1A GND
1B GND DC EARTH
1C
1
1D
(L) Mains LIVE 1E
2
1
1F 2
LL
1G
NN
1H
(N) Mains NEUTRAL 1J
1K
(7) DC +ve
1L 7
1M 8
1N 9
1P
11 (8) DC –ve
10
12
1Q 11
13
1R 12
14
1S 13
15
1T 14
Site 1 I/O 1U
16
15
customer 1V
17
16
terminals (1A-1Z) 1W
18
17
19
1X 18
20
1Y 19
21
1Z 20
22
21
22
Figure 3-2 Customer terminals — MAINS (left) and DC (right) options
Tutorial
SWITCH SETTINGS
A bank of eight on-board switches must be configured for this tutorial. To access them
you have to remove the T640 from its sleeve.
Removing the T640 from its sleeve
Caution
Handling precautions. Some of the circuit boards inside the T640 contain elec-
trostatically sensitive components. To avoid damage, before you remove or han-
dle any board ensure that you, the working area, and the board are electrostatically
See Figure 3-3. To unlock the T640 insert a small screwdriver blade into the slot in the
retaining clip at the bottom of the fascia and slide the clip to the left as far as it will go.
Repeat this for the clip at the top of the fascia, but slide it to the right. To withdraw the
unit use the extractor tool supplied in the accessory kit (Part No. BD 082253). Hold the
tool at an angle of about 45°, insert the hook into the opening under the ‘SP-W’ pushbut-
ton, then level the tool and pull the unit from the sleeve.
0%
PV-X SP
INS R A
??
ALM SP-W M
Extractor tool Retaining clip
Figure 3-3 Removal of T640 from sleeve
Setting the switches

Figure 3-4 shows the location of switchbank 1 (SW1) on the T640 motherboard, and also
SW1 in detail. Set the switches as shown. Note that for this tutorial the settings of the
switchbank SW2 switches are ‘don’t care’.
Replace the unit in its sleeve. You are now ready to power up the T640, but before doing
this you should be introduced to control strategy #1 — a single control loop.
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1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8
ON ON
1 2 4
OFF
SW1
ON
1 2 3 4 5 6 7 8
Cold start enable
Warm start enable Strategy selection

(#1 selected)
Figure 3-4 SW1 location and settings
STRATEGY #1 — SINGLE LOOP CONTROLLER

This simple strategy is a single loop controller using one ‘I/O site’, i.e. the column of ter-
minals labelled 1A to 1Z. Figure 3-5 shows an example P & I (piping and instrumenta-
tion) diagram for the strategy, with the T640 connected to a flow-control valve and an ori-
fice-plate flow sensor. The measured flow PV is input to the T640, where a PID (propor-
tional-integral-derivative) calculation compares PV with the setpoint to produce a 3-term
control output 3T OUT. This is fed to the valve controlling the flow.
Figure 3-6 shows the same control scheme but highlights very schematically the three
main areas of software inside the T640 that are responsible for running the strategy. The
‘PV input’ software takes in the measured PV as an analogue voltage and applies ranging,
conditioning, limiting, and alarms, before passing the signal to the ‘PID control’ area.
Here, the setpoint and PV are fed into the PID algorithm which calculates a value for the
control output needed to be applied to the valve to achieve optimum flow control. Other
operations done in the PID control area include ranging, limiting, alarm detection, control
mode selection, manual intervention, and application of PID algorithm tuning constants.
Tutorial
Local
setpoint
PV
3-term
output
Figure 3-5 Example P & I diagram for strategy #1
PV PID CONTROL
INPUT CONTROL OUTPUT
area area area
Flow sensor Flow control

(orifice plate) valve
Figure 3-6 Main software areas — strategy #1
The last area — ‘Control output’ — handles output conditioning, ranging, power-up and
failure modes.
This tutorial will show you how to access these software areas — via T640’s front-panel
buttons and displays — and configure their parameters to suit your particular plant control
requirements.
Tutorial
POWER-UP
Power-up messages
Switch on the power to the instrument. You may be quick enough to see the message
Power-on flashing briefly in the red tag display at the top of the fascia (see Figure 3-7).
Then ColdStrt Trying flashes, telling you that T640 is attempting a ‘cold startup’ of the
single loop database (strategy #1). Next, if the strategy is being loaded for the very first
time, you will see Un Pack Database flashing in the tag display as the strategy #1 file
(which you selected via SW1) is being decompressed from storage in ROM. You may
also hear the clicking of a relay closing and opening just after these messages.
Finally, the fascia adopts the normal display shown in Figure 3-7.
NOTES. 1) Slightly different power-up messages may appear if someone else

has used the T640 before you — e.g. TepidSrt Trying or WarmStrt Trying.
2) If what has just been described fails to happen and you get an error
message (e.g. Err 6001), first check that you have set SW1 correctly. If necessary
refer to Chapter 8, Error conditions & diagnostics, for further information.
Tag display ε T640

10
Units display
80
PV-X
5-digit display
60
Output bargraph
OUT-Y
PV bargraph 40
SP bargraph
20
Deviation bargraphs
Mode letter
0%
‘Displayed loop’ PV-X SP

arrowhead
INS R A
??
Pushbuttons
ALM SP-W M
Figure 3-7 T640 front panel — initial power up
Tutorial
The initial display

Refer to Figure 3-7. FIC-001 in the red tag display is the loop’s ‘tagname’, appropriate to
a flow controller. Note that you can select an alternative tagname if you wish — see Table
5-5 in Chapter 5 — but ‘FIC-001’ will do for this tutorial. The green 0.00 appearing in
the units display — accompanied by the glowing green SP-W legend — shows the loop’s
setpoint (SP) value. The red 5-digit display shows the current PV value (also 0.00), ac-
companied by the glowing red PV-X legend.
The two bargraphs at the left of the fascia, sharing a 0-100% scale, also display PV and
SP as red and green vertical bars, respectively. They presently indicate zero — only the
bottom LEDs are lit.
Note the brownish-yellow letter M flashing above the green arrowhead just above the set
of pushbuttons, together with the flashing yellow LED in the M (Manual) pushbutton.
The brown letter M means that the loop displayed on the fascia is in Manual mode, and its
flashing — together with the flashing button yellow LED — means that manual mode se-
lection has been forced by an alarm condition.
Finally, note that the ALM (alarm) button shows a steadily-glowing red LED. This draws
your attention to the fact that an alarm condition exists somewhere in the instrument.
INVESTIGATING THE ALARM CONDITION

Whenever the ALM button LED is lit you can quickly trace the source of the alarm as fol-
lows. (Figure 3-8 shows these how the ALM button works.)
1 Press ALM briefly. The tag display shows LOOP 1, and LOOP appears in the green
units display. This tells you that the alarm is in Loop 1.
2 Press ALM again. The tag display shows SETP1, and BLOCK appears in the green
units display. This localises the alarm condition to a specific area of the control data-
base called a ‘function block’, the name of the block in this case being ‘SETP1’.
(Function blocks are explained in more detail below.)
3 To see if there are any other Loop 1 blocks in alarm, press the ‘raise’ ▲ button. The
tag display now shows PV__1, indicating that a block called ‘PV__1’ is also in alarm.
4 Investigate the PV__1 block’s alarm by pressing ALM again. The tag display shows
Hardware, with SubFd showing in the units display. This tells you that the particular
type of alarm involves the T640 hardware in some way, ‘Hardware’ being the name of
the Alarm ‘subfield’ within the affected block. (Subfields are explained in the Func-
tion blocks section below.)
5 To see if there are any other alarms in the PV__1 block, press the ‘lower’ ▼ button.
This changes the tag display to OCctdel, which indicates that an open circuit has been
detected on the PV input. This is not surprising since you have not connected any-
thing to the input terminals other than the power supply! Note that the hardware alarm
you just saw is itself due to the open-circuit condition rather than to any other hard-
ware fault, though this would not always be the case.
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ALM
Enter ALARM INSPECT mode
Select other LOOP in alarm

LOOP 1 LOOP 2 LOOP 4
LOOP
ALM
Select other BLOCK in alarm

PV1 SWS1 TRIM1 SETP1
BLOCK
ALM
HighAbs
Select other Alarm SUBFIELD in alarm

Hardware Combined LowAbs
SubFd
UnAcd
ALM
Hardware Hardware
AlAck AlAck
UnAcd ACKNOWLEDGE Alarm
ALM ALM
Figure 3-8 Alarm inspect button functions — ALM
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6 Press ▼ again. Combined appears in the display. This is the ‘combined’ or ‘com-
mon’ alarm that is always asserted when any other alarm in a block trips.
7 Finally, escape from the ‘alarm inspect mode’ by briefly pressing any one of the R, A,
M, or SP-W buttons. If you do nothing for two minutes a timeout will in any case op-
erate to revert the fascia to its normal display automatically.
WATCHDOG RELAY
The clicking you may have heard when you powered up the T640 was due (in part) to the
closing and opening of the Watchdog relay. The contacts of this relay are connected to
customer terminals 16 and 17. The watchdog relay is normally closed when the T640 is
running and its CPU is healthy. It opens on CPU or power failure, but has also been con-
figured to open if an alarm occurs and remains open until the alarm condition has been
cleared.
You can check this by connecting a multimeter set to measure resistance across terminals
16 and 17. These will be open circuit, indicating an alarm condition — the hardware
alarm in the PV__1 block.
FUNCTION BLOCKS
Blocks
Figure 3-6 (on page 3-5) divided the control database into three broad areas. In fact, each
of these areas is further subdivided into pre-defined packages of software, having defined
and specialised functions in the running of the control strategy. These are the function
blocks, or ‘blocks’ for short. Every block has a tagname for reference, and can perform its
own specific task in the strategy, e.g. the block called PV__1 is an analogue input block
type that takes in analogue signals from the plant, processes them, and passes the results
on to other blocks in the strategy via ‘wiring’ between the blocks.
Other block types perform such tasks as setpoint generation, PID calculation, digital input,
analogue output, mathematical and logical operations, and so on.
Fields & subfields

Each block includes a collection of database values — fields — some of which are subdi-
vided into subfields. Note that in the four fixed-function strategies, all the necessary
blocks have been installed and wired together for you — all you need do is set some of the
block fields to specific values to tailor the strategy to your own plant requirements.
Tutorial
PV INPUT PID CONTROL CONTROL OUTPUT

area area area
PV__1 SETP1 OUTP1 1A (+)

analogue setpoint analogue 4-20mA
input block output 1B (–)
1E block block
3TRM1
OP__1
3-term
analogue
block
output 1L 0-10V
block
MANS1
manual
station
block
1N
Clean instrument earth
Figure 3-9 Strategy #1 schematic
Alarm fields
Alarm conditions are represented in each block by an Alarms data field. This field is fur-
ther divided into subfields, which become TRUE when the corresponding alarm condition
arises. It was these subfields that you just inspected via the ALM pushbutton.
Figure 3-9 shows strategy #1 in a little more detail, with some of the blocks named and
their block types indicated. Also, some of the customer terminals are shown, where plant
can be connected. You will need this information to progress with the tutorial.
Block functions
PV input area
As already stated, PV__1 is an analogue input block that takes in a voltage signal from the
plant (the orifice plate in this example) via terminal 1E. PV__1 ranges the input signal to
engineering units, filters, characterises, and conditions it (e.g. applies square-root for an
orifice plate signal). PV__1 also checks for alarm conditions including I/O hardware, out-
of-range and open-circuit inputs. And as you have just seen, the block detected the fact
that its input is in open-circuit.
PID control area

In the PID control area of the database, the SETP1 (setpoint) block generates a resultant
setpoint from the local setpoint you can enter via the front panel, and subjects it (and PV)
to ranging, high/low limits, trim, rate limits, and also provides absolute and deviation
alarms. The 3TRM1 (3-term) block generates a 3-term control output from PV and SP,
and lets you alter the loop’s tuning constants. The MANS1 (manual station) block applies
high and low limits to the control output.
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Control output area

In the control output area, OUTP1 is an analogue output block configured to provide an
isolated 4-20mA control output to the plant, via T640’s hardware. This is available on
customer terminals 1A and 1B, as shown in the Figure. Also available — via another ana-
logue output block OP__1 configured to output volts — is a 0-10V control output on ter-
minal 1L. (Any of terminals 1G, 1K, and 1N provide the analogue ground.) The 0-10V
output follows the 4-20mA output. Figure 3-2 showed the I/O customer terminals 1A-1Z.
SIMULATING A FEEDBACK LOOP

Figure 3-9 shows that the 0-10V control output appears on terminal 1L — which could in
a real plant be connected to a suitable control valve. The PV input from the orifice plate
would be connected to terminal 1E for input to the PV__1 block. You can simulate this
control loop by feeding the control output back to the PV input. Do this by simply con-
necting a wire between terminals 1L and 1E.
Note that within a few moments of connecting the wire the red ALM button light goes out
(showing the alarm condition has cleared), the M button’s yellow LED stops flashing
(meaning that normal ‘un-forced’ manual mode now operates), and the watchdog relay
closes (which you may see on the multimeter if still connected).
If you now press the ALM button, the message NoAlm appears in the tag display, mean-
ing no detected alarm condition now exists in the instrument.
With the control loop complete, you can now investigate the strategy further.
DISPLAYING & ALTERING THE LOCAL SETPOINT

The resultant setpoint is currently 0.00 units, as shown in the green units display (see Fig-
ure 3-7). Alter this to about 50 units as follows:
1 Press the SP-w button to display the local setpoint (0.00) in the red 5-digit display.
With SP-w pressed, SetLocal appears in the tag display to remind you what is being
displayed. The setpoint’s units (‘Eng1’) are shown in the green units display.
2 Keeping SP-w pressed, hold down the ▲ button and watch the local setpoint value
increase — slowly at first, then more and more rapidly. Raise it to about 50 units, then
release both buttons. The new resultant setpoint shows in the green units display — it
should equal the local setpoint you just configured. Also, the green SP vertical bar-
graph now displays the resultant setpoint in percentage units. (These happen to equal
the engineering units, with the default ranges currently configured.)
Note the negative value now displayed by the Loop 1 deviation bargraph — i.e. the
red LEDs are lit below the central green zero LED. Full-scale (all 3 segments lit) rep-
resents about 10% deviation (PV–SP).
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3 Try lowering SP again to zero, by pressing SP-w and ▼ together. Note how the green
units display shows Limit if you try to reduce SP below zero. This tells you that you
have hit a configured low limit of 0.00 on the setpoint value. Similarly, you meet an-
other limit if you try to raise SP above 100.00 units.
4 Finally, restore SP to about 50 units.
NOTE. While you have been varying SP, the PV value — as shown by the PV
bargraph and the red 5-digit display — has remained at zero. This is because the
control loop is still in manual mode and is therefore exerting no control action.
Automatic mode will be looked at next.
SELECTING ANOTHER OPERATING MODE
Automatic mode
With SP still at about 50 units, p ress the A button to select automatic mode. Its green
LED lights — confirming that auto mode has been adopted — and the M button’s yellow
LED goes out. As soon as auto is selected the control output begins to rise due to the ac-
tion of the PID algorithm in the PID control area of the strategy.
NOTE. While A is pressed, OUTPUT appears in the tag display and the fascia
shows the current control output value and its units (%).
You can see the control output displayed in the horizontal output bargraph, labelled OUT-
Y. Each of its yellow segments represents about 10% of full range output.
The (simulated) PV value also rises, of course, and shows itself on the red PV-X vertical
bargraph at the left of the fascia, and also in the 5-digit display. Once the controller has
settled down in auto, PV and SP should adopt the same value in this simulation.
The deviation bargraph now shows zero deviation, with just the central green LED lit.
The letter A glows in green below the deviation bargraph denoting automatic mode for this
loop.
Manual mode
You can press the M button at any time to select manual mode. Note that pressing M also
displays the control output value and units. But in manual mode you can alter the output,
not just display it.
Try raising the control output to 100% by pressing M and at the same time pressing the ▲
button. You will see the PV and deviation bargraphs rise to their maximum indications.
‘Limit’ appears in the green units display, because PV has reached its configured limit.
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Remote mode
Pressing the R button cannot select remote mode in this simple loop simulation. Instead,
the A button’s green LED (and the letter A below the deviation bargraph) flashes indicat-
ing that ‘forced automatic’ mode has been adopted. This happens if you try to select re-
mote when it has not been enabled, or if the remote setpoint is invalid. Control action is
still exerted in this mode. If you don’t want remote mode to be selectable you can disable
(‘mask’) the R button. This is explained later under Pushbutton masking on page 3-23.
Press A to restore normal automatic mode.
POWER INTERRUPTIONS
Warm start
Remember when you powered up the T640 at the start of the tutorial you saw the message
ColdStrt Trying, and the instrument performed a cold start. After a cold start the data-
base is initialised and therefore in its default state. Remember also that you set the SW1
switches to enable both cold and warm starts. This enables the T640 to perform a warm
start if possible. After a successful warm start the instrument resumes running the control
strategy having remembered or regenerated all the database values as they were at the mo-
ment of power interruption. Try a warm start now:
1 Check that you have automatic mode selected, and a PV value other than the default of
0.00.
2 Switch off the power to the T640, either at source or by withdrawing the instrument
from its sleeve.
3 Restore the power after a few minutes. The message WarmStrt Trying flashes in the
tag display, and after a few moments the fascia adopts the state it had at power-down,
i.e. a warm start has been performed.
Cold start
Now try interrupting the power with the warm start enable switch OFF:
1 Access the interior of the T640 and set SW1 switch 4 to OFF — but leave switch 3
ON.
2 Re-insert the T640 in its sleeve to restore power. A cold start is performed, and the
strategy starts in its default state, having ‘forgotten’ your modifications to it.
Tepid start
A ‘tepid’ start is a type of warm start, but not quite as good because only some of the data-
base values are restored at power up — including local setpoints, control outputs, and op-
erating modes. Tepid starts occur when the RAM database has been corrupted; it’s possi-
ble that you may have seen one when you powered up the T640 at the start of this tutorial.
(For more information please refer to Chapter 2, under Power up routine.)
Tutorial
INSPECTING & EDITING THE DATABASE

Using INS
This section of the tutorial shows you how to inspect and modify parts of the database to
tailor the strategy to your particular needs. The first thing you will look at is ranging the
setpoint and process variable engineering units. After that you will go on to apply high
and low limits to the local setpoint (SL), and then configure absolute and deviation alarms
on PV. Finally in this section, you will set up a new decimal point position for the front-
panel display.
The function block concerned with this part of the control strategy is the SETP1 (setpoint)
block, which was shown in Figure 3-9 in the ‘PID control area’ of the database. To carry
out modifications you must access the relevant fields inside the SETP1 block. To do this
you use the INS (‘inspect’) pushbutton on the front panel.
Table 3-1 lists each of the configurable fields within the SETP1 block, together with its
default value, target setting, and a brief description of its function in the strategy. This list
will be useful when you are navigating around the fields to configure them. Note that a
complete list of blocks and fields for each of the fixed-function strategies is given in the
setup sheet included in this manual (at the end of Chapter 5).
Block Field Subfield Default Setting Description

SETP1 HR_SP 100.00 75.00 Engineering unitshigh for SP and PV
LR_SP 0.00 Engineering units low for SP and PV
HL_SP 100.00 High limit on SP
LL_SP 0.00 Low limit on SP
HL_SL 100.00 60.00 High limit on SL
LL_SL 0.00 Low limit on SL
Alarms HighAbs 2 Alarm priority on HAA
LowAbs 2 Alarm priority on LAA
HighDev 2 Alarm priority on HDA
LowDev 2 Alarm priority on LDA
HAA 100.00 70.00 High absolute alarm on PV
LAA 0.00 30.00 Low absolute alarm on PV
HDA 100.00 10.00 High deviation alarm on PV
LDA 100.00 10.00 Low deviation alarm on PV
Dis_DP 2 3 Decimal point position
Table 3-1 Configurable fields in the SETP1 (setpoint) block
Configuring ranges and limits

Figure 3-10 shows how the INS button works.
1 Press the INS button briefly. LOOP 1 appears in the tag display — this is the loop
ready to be inspected, and it is the loop that contains the SETP1 block. The green
units display shows LOOP (meaning ‘loop access mode’).
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INS
Enter INSPECT mode
??
LOOP 4
Select LOOP
LOOP
INS
??
Select BLOCK
BLOCK
INS
?? Options
Select FIELD
Alarms HR_in LR_in
FIELD
INS
?? Hardware
(Select SUBFIELD)
Software Combined UCharErr
SubFd
+ 1
INS
??
Software
Select VALUE
VALUE INCREMENT value (or set TRU
+ 1
DECREMENT value (or set FALS
INS
??
Figure 3-10 Inspect button functions — INS
Tutorial
NOTE. If you now press either ▲ or ▼ you will see another ‘loop’ — LOOP 4
— in the tag display. Loop 4 is not actually a control loop, but is a second inde-
pendently-running section of the database (‘user task 4’) that you can access via
the INS button. Loop 4 contains, among other items, configuration data on T640
communications, which do not concern us here.
2 With LOOP 1 in the display, press INS again. The units display changes to BLOCK,
denoting ‘block access mode’, and the tag display now shows the name of the first
block in the Loop 1 (i.e. ‘User task 1’) area of the database. This block may or may
not be the one you want (SETP1) depending on how the T640’s memory module has
been programmed at the factory.
3 In any case, now press the ▼ button to move down to the next block in Loop 1 and see
its name in the tag display.
4 Press ▼ again repeatedly to see all the blocks in Loop 1 that you can access for in-
spection or modification. There are 13 altogether. Use ▲ to move up the list again, if
you go past the block you require. Access the SETP1 block.
5 With SETP1 in the tag display, press INS again. This gets you into ‘field access
mode’ as shown by FIELD in the units display. The tag display now shows the first
accessible field in the SETP1 block, which is called HR_SP. This field stores the high
range in engineering units for SP and PV. Its current (default) value is shown in the
red 5-digit display as +100.00. In the next step you will alter this value, but before do-
ing this try accessing the other fields in the SETP1 block using the ▲ and ▼ buttons
to move around the list. There are 12 fields in all (see Table 3-1). Get back to HR_SP
for the next step.
6 With the HR_SP field selected, press INS again. VALUE appears in the units display,
telling you that you can update the field value. Press ▲ to raise the value, or ▼ to
lower it, to the one you require (subject to any configured limits). For this tutorial,
lower the high range to 75.000 engineering units.
7 You now want to move on to the HL_SL field in the block, which specifies a high
limit value for the local setpoint SL. Press INS three times to return to ‘field access
mode’ with HR_SP still accessed (T640 has remembered your selections). Then press
▼ once to access LR_SP (which you will leave at zero) and then three more times to
reach HL_SL. Adjust this to 60.000 by pressing INS to get into ‘value update mode’
as before, then use ▲ or ▼ as needed. Then return to field access mode by pressing
INS three times.
Tutorial
Configuring absolute and deviation alarms

In this stage of the tutorial you set new values for the high and low absolute and deviation
alarms.
1 Access the HAA field in the SETP1 block, as before. (If you’ve forgotten how to do
this, have a look at the previous section again to remind yourself!). HAA specifies the
high absolute alarm limit on PV, i.e. the PV value which if exceeded trips the high ab-
solute alarm (which you will inspect soon). Its default value is 100.00. Press INS to
access value update mode and lower the HAA value to 70.000 units. Press INS three
times to return to field access mode.
2 In the same way, set LAA (low absolute PV alarm) to 30.000, and set HDA & LDA
(high and low deviation alarms, respectively) to 10.000 each.
Configuring the decimal point

1 Access the Dis_DP field, which stores the decimal point position used in the 5-digit
and the units displays. To do this quickly you can, once into field access mode, just
press the ▲ button once to get you directly to the end of the field list, which is cyclic.
2 Set Dis_DP to 3 (decimal places), then press A to return to the normal display and see
the effect of this change.
Alarm subfields
In this next stage of the tutorial you inspect the subfields of the Alarms field in the SETP1
block. To do this:
1 Use the INS button as before to access the Alarms field in the SETP1 block.
2 Press INS again. This time, instead of entering ‘value update mode’ you see SubFd in
the green units display, denoting ‘subfield access mode’. This is because the Alarms
field consists of a set of subfields, unlike the range and limit fields you have met so
far. The first subfield accessed is shown in the tag display — Software — and its cur-
rent value appears in the 5-digit display — 1. This is the priority of the Software
alarm, which you should not alter at this stage. (You would alter it in the same way as
described above, using the INS and ▲/▼ buttons.)
3 Still in subfield access mode, press ▼ to move to the next subfield in the Alarms field
— HighAbs. This is the PV high absolute alarm, which trips if PV exceeds the high
limit (specified in the HAA parameter). Its priority of 2 should be left as is.
4 Go on to inspect the rest of the Alarm subfields in the same way. Finally return to the
normal fascia display by pressing the A button. You may have noticed that if you do
nothing for two minutes a timeout operates automatically to escape from ‘inspect
mode’.
Tutorial
EFFECT OF THE ALARM SETTINGS AND LIMITS ON THE

FRONT-PANEL DISPLAYS
You can see the effects on the fascia displays of the limits and alarm levels just config-
ured. Start by setting SP to about 50 units with the loop in auto. Let the displays settle.
Inspecting absolute and deviation alarm settings

1 To see these values directly on the PV-X and SP-W bargraphs, press and hold down ▲
and ▼ together. ALM_SET (‘alarm settings’) appears on the tag display. On the PV
bargraph the upper and lower limits (HAA and LAA) appear as a pair of reverse-lit
segments superimposed on the bar. This display lets you see immediately where PV is
in relation to the limits. At the same time the high and low deviation limits (HDA and
LDA) are superimposed on the SP bargraph as reverse-lit segments. These mark the
levels above and below the current SP-value, which move up and down with it. If PV
goes outside these levels a deviation alarm trips.
Effect of local setpoint limit

The setpoint limit you set up (in HL_SL) shows itself when you try to adjust the local set-
point:
1 Raise the setpoint as far as possible by pressing SP-w together with ▲. When the
value reaches 60.000, Limit appears in the units display.
Annunciation of absolute and deviation alarms

Produce alarm conditions and see the effects on the displays:
1 Lower the setpoint (from 60) to about 20 engineering units. The green SP-W bar-
graph starts to flash as soon as the setpoint has fallen far enough to trip the high devia-
tion alarm. At the same time the deviation bargraph also flashes, and the ALM button
light comes on. Shortly after this, when PV has fallen below its low limit (in LAA),
the PV-X bargraph starts flashing to warn you that the low absolute alarm has tripped.
NOTE. You may also have heard the watchdog relay click open, which it is con-
figured to do by any priority 2 alarm.
2 After a while, when the fascia has settled and control has been regained (PV = SP),
only the low absolute alarm remains. Trace this alarm via the ALM button. You
should find LowAbs (and Combined) alarms in the SETP1 block.
3 Finally, restore the setpoint to about 50 units to clear all alarms.
Tutorial
INSPECTING & EDITING THE PV INPUT AREA

This section gives you some more practice at using the INS button to access the fields in
the PV__1 (analogue input) block. Remember, PV__1 takes in and conditions the signal
from the orifice plate (in this example). Specifically, you will inspect and edit the input
filter time constant, and apply a square root function to the signal from the orifice plate.
Table 3-2 lists the PV__1 block’s configurable fields and target settings.

PV__1 Filter 1.00 2.00 Input filter
RomChar None Input conditioning
Alarms Hardware 2 Alarm priority
OutRange 2 Alarm priority
OCctdel 2 Alarm priority
HR_in 10.00 Input voltage high
LR_in 0.00 Input voltage low
Options Invert FALSE Input conditioning
Sqrt FALSE TRUE Input conditioning
Table 3-2 Configurable fields in the PV__1 (analogue input) block
Start this section with the T640 set up as at the end of the previous section.
1 Press INS twice to access block inspect mode, then press ▼ (if needed) to bring up the
PV__1 block.
2 Press INS again to access the first field in the PV__1 block — Filter.
3 Press INS again, then increase the value of the filter time to 2.00 (seconds) using the
▲ and ▼ buttons.
4 Press INS three times to return to field inspect mode.
5 Access the RomChar field and inspect its contents by pressing INS again (to access
VALUE mode) and using ▲/▼. As you edit the ROM-based characterisation func-
tions stored in the RomChar field you may notice the front-panel displays altering to
re-establish control under the new conditions you are creating! Return the RomChar
value to None (the default) before continuing.
6 Access the Options field in the usual way. This field lets you apply an inversion to
the input signal, and/or a square root function.
7 Press INS to see the Options subfields. The first is Invert which is FALSE by default
— i.e. no inversion.
8 Press ▼ to move to the second subfield — Sqrt (square root).
9 Press INS again and set the value to tru (TRUE) using ▲. (▼ restores FALSE.) You
will see the front panel respond as PV changes value.
10 Finally, press the A button to return to the normal display.
Tutorial
SAVING A DATABASE
Now that you have reconfigured several of the fields in the control strategy you will want
to save it to EEPROM, where it will be safe and effectively permanent. At the moment
your customised strategy exists only in RAM, which although battery-backed in the T640
is inherently a volatile memory medium.
To save your database currently in RAM you must access a function block called T60_00.
(The last two digits are the node number, and may differ from ‘00’. Ignore this in the tuto-
rial!) This block contains a field called Options. Within Options is a subfield called
FullSave. You set this TRUE to effect the save to EEPROM.
1 Press INS to access loop inspect mode.
2 Press ▲ or ▼ to move to LOOP 4, which is the user task containing the T60_00
block.
3 Press INS again to inspect the blocks in Loop 4. The first one is USR_ALM, which
stores the alarm priority needed to trip the watchdog alarm relay (currently set at 2).
4 Move to the next block — T60_00 — and press INS to see the Options field, which is
the only accessible field in this block.
5 Press INS again to see the Options subfields, and move down the list until you reach
FullSave.
6 Pres INS and set the value to tru by pressing ▲. The message SAVING . . appears in
the tag display as the save is executed, and the value of the subfield automatically re-
turns to FALSE. After a few moments the tag display reports Save OK. Press A to
return to normal mode.
Saved databases
Your customised database is now safely stored in EEPROM — under the same filename
that the original default database had. But note that the original fixed-function default
strategies will always reside in ROM and could be made to overwrite your customised
strategy!
To avoid this, if you intend to keep a customised strategy in EEPROM, do not reset the
SW1 strategy-select switches (switches 6, 7, and 8 in Figure 3-4). If you do, there is a
risk that at power-up a new strategy will replace your customised one in EEPROM.
It is OK to power up with the switches set to the original strategy that you subsequently
customised (#1 in this case). This is because when the T640 sees that the EEPROM al-
ready contains the strategy indicated by the switches, it loads it directly from EEPROM to
RAM and runs it without ‘unpacking’ (decompressing) a default database from ROM.
You can test the effect of your save as follows:
1 Remove the T640 from its sleeve and set the warm start enable switch to OFF. (Leave
the cold start enable switch at ON, and the strategy-select switches at #1.) Figure 3-4
shows the required SW1 switches. This action now ensures that the T640 cannot do a
warm start, only a cold start.
Tutorial
2 Power up again by replacing the T640 in its sleeve. You will see a cold start per-
formed but all your saved field values are preserved in your customised strategy.
Check this using INS.
3 Finally, return the warm start enable switch to ON.
INVESTIGATING THE LOOP SETUP ‘SWITCHES’

There is a set of 16 ‘software switches’ or bits within a block called SWS_1, in the PID
control area of the strategy. You can use them to specify the way the control loop oper-
ates. The SWS_1 bits select such things as the T640 power-up mode, inversion of control
output action, on/off control action, pushbutton disabling (‘masking’), and the tagname
that appears in the loop’s tag display. Table 3-3 lists the SWS_1 bitfields.
Try switching some of these bits from their default states (all but one are FALSE) to see
how they affect the control action.
Power-up/power-fail mode
1 Press INS twice to access block inspect mode, then press ▼ as required to bring up the
SWS_1 block.
2 Press INS again to see the only accessible field in the SWS_1 block — W Field1.
This consists of 16 subfields called Bit0 to BitF (hexadecimal ‘F’ is decimal ‘15’).
3 Press INS again, to access Bit0. Table 3-3 tells you that this bit selects the power-up
mode. Remember that power-up occurs after unexpected power interruptions — not
just when you switch on the T640. TRUE causes the loop to adopt manual mode on
power-up with zero electrical output for safety — i.e. 0V or 4mA. FALSE (the de-
fault) causes the loop to maintain its last mode and output value on power-up.

SWS_1 W Field1 Bit0 FALSE tru Power up mode
Bit1 FALSE PV fail mode
Bit2 FALSE tru - inverse output action
Bit3 FALSE tru - inverse PID
Bit4 FALSE tru tru - On/Off control
Bit5 FALSE tru - setpoint tracks PV if not AUTO
Bit6 FALSE tru - PV/SP Out = SP
Bit7 FALSE tru - inverse ratio setting
Bit8 FALSE tru - Mask R
Bit9 FALSE tru - Mask A
BitA FALSE tru - Mask M
BitB tru Tag FIC-001
BitC FALSE Tag LIC-001
BitD FALSE Tag PIC-001 If all bits FALSE, tag is LOOP 1
BitE FALSE Tag TIC-001
BitF FALSE Tag AIC-001
Table 3-3 Configurable fields in the SWS_1 (digital connection) block
Tutorial
4 Press INS and alter Bit0’s value to tru, then return to the normal display by
pressing A.
5 Now simulate a power interruption by switching the power off then on, and watch the
front panel displays. The T640 powers up in manual mode, and the control output
falls to zero. Check this by pressing the M button and reading the 5-digit display,
which should indicate 0.00% output. Restore control by re-selecting auto mode
(press A). Restore Bit0 to FALSE.
PV fail mode
1 Use the INS button to access Bit1 of the SWS_1 block. This bit determines what hap-
pens to the control output should the process variable input PV fail. In Bit1’s default
state (FALSE), the control output holds at its last value on PV failure. With Bit1
TRUE, however, the output falls to electrical zero (i.e. 0V or 4mA) on PV fail.
2 Set Bit1 to tru and press A to return to automatic mode. While A is pressed, note the
control output value in the 5-digit display.
3 Now simulate a PV failure by disconnecting the wire attached to terminal 1E. Notice
that the control loop adopts ‘forced manual’ mode — indicated by the flashing yellow
LED in the M button, and that the control output drops immediately to zero. (Press M
to check this.)
4 Reconnect terminal 1E and press A to restore control.
5 Reset Bit1 to FALSE, return to auto mode, then repeat the PV fail simulation. This
time the control output holds at its current value despite the loss of PV and adoption of
forced manual mode.
6 Finally, reconnect PV, press A, and allow equilibrium to return.
On/off control
1 Use the INS button to access Bit4 of the SWS_1 block. This bit selects on/off control
action (TRUE) or normal continuous control action (FALSE). With on/off action the
control output is either at 0% or 100% of range, with nothing in between.
2 Set Bit4 to tru and watch the chaos on the front panel as the simulated PV oscillates
above and below the setpoint trying to attain equilibrium! Restore Bit4 to FALSE.
NOTE. With a suitable Deadband value selected (via the 3TRM1 block), on/off
control can be applied successfully in appropriate plant situations.
Tracking of PV by the setpoint

1 Access Bit5 of the SWS_1 block. When TRUE, this bit forces the local setpoint to
track (i.e. follow) the process variable PV whenever the controller is not in automatic
mode. (It may be safer for SL to keep equal to PV in the event of a loss of control, so
that when control is eventually restored and auto mode resumed, there will not be a
sudden and possibly damaging change in control output value.)
Tutorial
2 Set Bit5 to tru and return to the normal display in auto mode (press A).
3 Now select manual mode by pressing the M button, then attempt to change the local
setpoint by pressing SP-w together with either ▲ or ▼. You won’t be able to!
4 Get back to auto mode and try again. Alter the setpoint to be as far as possible from
the current PV-value — e.g. to zero — then quickly switch back to manual mode.
Note how the setpoint rapidly equalises with PV.
5 Now raise the control output, by pressing M and ▲ together. Remember that in this
simulation the output is being used as a PV input, so you are also raising PV. Notice
how the green SP bargraph tracks the rising red PV bargraph, but not further than the
limit you configured earlier.
Pushbutton masking
This may be necessary if you want to prevent an operator selecting a particular mode via
the front-panel pushbuttons. Note that button-masking does not prevent modes being
changed by other means, e.g. automatically during a failure mode, or over the comms net-
work. When TRUE, Bit8, Bit9, and BitA disable the R(emote), A(uto), and M(anual)
mode select pushbuttons, respectively.
1 Access the Bit9 subfield of the SWS_1 block, and alter its value to tru. Return to the
normal display by pressing M.
2 Now try to select auto by pressing A. You will not succeed, and the message
MASKED appears in the tag display for about 3 seconds to tell you why.
NOTE. You may have seen the MASKED message at the start of this tutorial if
you pressed R or A before you connected the piece of wire to close the control
loop. These buttons are automatically masked in this strategy as a safety precau-
tion in certain alarm conditions.
3 Restore Bit9 to FALSE.
Tutorial
1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8
ON ON
1 2 4
OFF
SW1
ON
1 2 3 4 5 6 7 8
Cold start enable
Warm start enable Strategy selection

(#4 selected)
Figure 3-11 SW1 location and settings — strategy #4
HANDLING MORE THAN ONE CONTROL LOOP

You have nearly completed this tutorial, which has used as its example strategy #1 — a
single control loop. When there are two, three, or four control loops in a strategy the
front-panel display is able to show you a summary of the status of all the loops at once,
together with a more detailed display of one selected loop.
To see how this works in practice, load strategy #4, which has three control loops in it.
1 Withdraw the T640 from its sleeve and set the strategy select switches to #4.
Figure 3-11 shows the required SW1 switch positions.
2 Replace the T640 in its sleeve to power it up. After the initial database unpacking,
strategy #4 starts to run, and you now see three deviation bargraph displays illumi-
nated, instead of just one, each applying to one of the control loops.
Under one of the deviation bargraphs will be the green arrowhead; this identifies the
loop currently selected to occupy the main fascia displays. Its loop tagname is dis-
played in the tag display at the top of the fascia, and the rest of the displays refer only
to this selected loop.
3 Select a different loop for main display by holding down ▲ or ▼ to cycle around the
available loops. Let go when the required loop is indicated by the green arrowhead.
The main display now applies to your selected loop, whose tagname appears in the tag
display.
4 Try altering a variable of the current loop, e.g. raise its setpoint (by pressing SP-w and
▲ together). Note that the front-panel buttons also work only on the currently-se-
lected loop. This applies also to the ALM and INS pushbuttons.
User interface
Chapter 4 USER INTERFACE
This chapter describes how to use the T640 front-panel pushbuttons and displays to carry
out all the basic operations. The front-panel can also indicates failure states; please refer
to Chapter 8, Error conditions & diagnostics, for details. The present chapter concentrates
on the normal running of the T640.
Figure 4-1 shows the front panel, with a typical display.
Tag display
ε T640
10 Units display
80
5-digit display PV-X

Output bargraph
60
Deviation
OUT-Y bargraphs
40
PV bargraph
Central green
SP bargraph LED
20
R A A
M
Mode letter
0%
PV-X SP T
‘Displayed loop’
green
INS R A arrowhead
??
Pushbuttons Raise/lower
ALM SP-W M buttons
Figure 4-1 T640 front panel — the operator interface

Displays & controls User interface
OPERATOR DISPLAYS & CONTROLS
Summary loop displays

Figure 4-1 shows the front panel. Four summary displays show red deviation bargraphs of
T640’s four loops — Loops 1 to 4 from left to right. DevnBar, in the SETPOINT block,
specifies the bargraph span as ±3, ±10 (default), or ±30% deviation. PV can be displayed
instead, to 100% of range, if DevnBar = Abs_PV. The central green LED glows if the bar-
graph is showing deviation; the bottom red LED glows if PV is being displayed. A flash-
ing bargraph means the loop is in absolute or deviation alarm.
Operating mode letters glow to show selected modes for each loop: R = Remote,
A = Auto, M = Manual, T = Track, H = Hold). Flashing signifies a ‘forced’ mode. A to-
tally blank loop summary display and inaccessible main display mean the loop contains no
configured blocks, or the related T600 block FPdisn parameter is TRUE.
Main loop display

This details the status of one of the four loops, indicated by a green arrowhead under the
related summary bargraph. To select a loop for main display, hold down a raise ▲ or
lower ▼ button. If a loop’s MODE block SelDisp parameter is TRUE it will always oc-
cupy the main display and cannot be deselected. The following features apply only to the
loop selected for main display.
Tag display
This red display normally shows the TAG block’s TAG field. With no TAG block, the
PID/PID_CONN block name, or SETPOINT block name, or the default LOOP n message
appears. Special displays can override the normal display, as described in later sections.
PV-X bargraph display

Red display normally showing the SETPOINT (or PID) block’s PV value in 2% steps.
SP-W bargraph display

Green display normally showing the SETPOINT (or PID) block’s SP value in 2% steps.
5-digit display
Red display normally showing the PV value of the SETPOINT (or PID) block in engineer-
ing units. The PV-X legend (see Figure 4-1) glows red only when PV is being displayed.
Units display
Green display normally showing the engineering units associated with the 5-digit display.
It can also show the SETPOINT block’s SP value (Show_SP TRUE). In this case the
SP-W legend glows green.
NOTE. Pressing ▲ or ▼ displays units in this case.

User interface Displays & controls
Output bargraph
Yellow display normally showing the loop’s control output, i.e. the MAN_STAT block’s
MeasPos value, or its OP value if MPosDisp is FALSE, or if absent the PID block’s OP
value. All segments lit represents 95% of full range. Note that each bargraph segment can
also be driven individually via the MAN_STAT block’s UserBar parameter.
Mode changes
You interact with the main display loop via the eight front-panel pushbuttons. Press
M(anual), A(uto) or R(emote) to select the related mode — strategy permitting. The but-
ton’s top-right LED glows if the mode is adopted; both R LEDs glow green in ‘computer
remote’ mode. A flashing LED signifies a ‘forced’ mode. If a mode button is inhibited
(by the MODE block’s PBmasks parameter, or by a SelMode bit), the tag display is over-
ridden by the word MASKED for 3 seconds and no mode-change occurs.
Output display
Holding down a mode button also displays the current value of the control output in the 5-
digit display and its units in the units display. The word OUTPUT or MeasPos appears in
the tag display (with A or R pressed), or MS_Dmnd (with M pressed). For the simple
PID block only OUTPUT appears.
Changing the output

With M pressed and the controller in Manual, press ▲ or ▼ to vary the value of the
MAN_STAT block’s Demand field (or the PID block’s OP field). Full-range change takes
about 12 seconds.
Output parameters — quick access

With any of M, A, or R pressed, press INS (Inspect) repeatedly to scroll the 5-digit dis-
play through the MAN_STAT block’s primary output parameter values.
These are: OP (OUTPUT), Demand (MS_Dmnd), MeasPos (MeasPos), PV (MS_Input),
and Track (MS_Track), identified in the tag display. Only OP and Track are available
from simple PID blocks.
Setpoint display
Press SP-W to display the SETPOINT (or PID) block’s SL value in the 5-digit display.
When in Remote mode the corresponding remote setpoint is seen. With SP-W pressed,
SetLocal or RemoteSP appears in the tag display.
Changing the setpoint

To vary the value of SL, press SP-W together with ▲ or ▼. Full-range change takes about
30 seconds.

Database access User interface
Setpoint parameters — quick access

With SP-W pressed, press INS repeatedly to scroll the 5-digit display through the primary
setpoint parameter values. These are: SL (SetLocal), SP (SetPoint), RemoteSP,
ComRemSP, and TrimSP, identified in the tag display. ComRemSP is not available from
simple PID blocks.
Absolute & deviation alarm settings — viewing

Press ▲ and ▼ together to superimpose the absolute alarm settings on the PV-X bargraph,
and the deviation alarm settings on the SP-W bargraph, as pairs of reverse-lit LEDs. The
tag display shows ALM_SET.
Absolute & deviation alarm annunciation

For the main loop on the display, an absolute alarm flashes the red PV-X bargraph and a
deviation alarm flashes the green SP-W bargraph. For the four summary loop displays,
either alarm flashes the relevant summary deviation bargraph.
DATABASE ACCESS
The INS button lets you inspect and edit database parameters. Two access modes are
available — ‘Full’ and ‘Partial’ — requiring a ‘Full’ or ‘Partial’ security key (unless the
need for a key is overridden in the T600 block). If necessary, refer to the Security key sec-
tion at the end of this chapter for how to use the key.
Both modes work in the same way, but Partial mode can access only a limited set of
blocks and fields. Parameter changes during database access are automatically logged by
the T640 in a special EEPROM file — see Chapter 6, Changes logfile.
To access the current database, press INS repeatedly as required to cycle through the fol-
lowing hierarchy of database access modes; the green units display shows the access level
reached.
Figure 4-2 shows how the INS button works.
1 Loop Access mode

The first INS press selects this mode, and LOOP appears in the green units display. Un-
less overridden, a security key must be active for initial entry into this mode.
NOTE. If the message ‘No Key’ appears in the tag display, you will not be per-
mitted to access inspect mode without a valid security key — see below in the
section Security key for details.
Press ▲ or ▼ to select a loop for inspection, indicated as LOOP n (or Cached) in the red
tag display. The initially selected loop is the same as the main display loop. (Press ALM
to see the loop repeat rate, in seconds, in the 5-digit display.)

User interface INS button
INS
??
Enter INSPECT mode
LOOP 4
Select LOOP
LOOP
INS
??
Select BLOCK
BLOCK
INS
?? Options
Select FIELD
Alarms HR_in LR_in
FIELD
INS
?? Hardware
(Select SUBFIELD)
Software Combined UCharErr
SubFd
+ 1
INS
??
Software
Select VALUE
VALUE INCREMENT value (or set TRU
+ 1
DECREMENT value (or set FALS
INS
??
Figure 4-2 Inspect button functions — INS

Database access User interface
2 Block Access mode

The second INS press selects this mode, and BLOCK appears in the units display. Press
▲ or ▼ to select a block for inspection. Block tagnames appear in the tag display in
execution order. (Press ALM to see the block Type in the Tag display.)
3 Field Access mode

The third INS press selects this mode, and FIELD appears in the units display. Press ▲
or ▼ to select a field for inspection. The tag display shows the field’s name, and the 5-
digit display shows its value (format permitting). (Press ALM to see the field’s units in
the Tag display.)
4 Value Update mode, Connection Enquiry mode, Subfield Access

mode
The fourth INS press selects one of these three modes, depending on the type of field ac-
cessed:
■ Value Update mode. VALUE appears in the units display, or Ronly (read-
only) if update is not permitted. Press ▲ or ▼ to vary the field value, indicated in the
5-digit display (or in the tag display if text). Limit in the units display indicates that a
limit has been reached. Pressing INS at this point returns you to Loop Access mode.
Further INS pressing cycles through the access mode hierarchy, retaining your latest
selections.
■ Connection Enquiry mode. If the field has a connection into it, barring
manual update, Conn. appears in the units display. The tag display shows the first 8
characters defining the source point. Press ▲ or ▼ to see the rest. Press INS to return
to Loop Access mode.
■ Subfield Access mode. If this is a subfield, SubFd appears in the units display.
Press ▲ or ▼ to select a subfield within the current field. The tag display shows the
field’s name, and the 5-digit display shows its value (format permitting).
5 Subfields
If this is a subfield, the fifth INS press selects subfield VALUE or Conn. modes, used as
already described.
Quitting database access modes

Pressing R, A, M, or SP-W immediately reverts the T640 to standard operation. A time-
out can also be set in the T600 block to revert the display after a defined period of no but-
ton activity.

User interface Alarm inspection
ALARM DISPLAY & INSPECTION

Whenever any unacknowledged alarms exist in the loop occupying the main display, the
highest priority alarm name flashes in alternation with the standard message in the tag dis-
play. Unacknowledged alarms elsewhere display LP n ALM, where n is the relevant loop
number.
Any alarm in the instrument — in any of the loops — lights the red LED in the ALM but-
ton. The LED flashes if any alarm is unacknowledged; otherwise it remains steady.
Alarm inspection via the ALM button

The ALM button lets you quickly locate and acknowledge alarms, wherever they are.
Figure 4-3 shows how the ALM button works.
1 Press ALM to enter Loop (Alarm Inspect) mode, indicated by LOOP in the green
units display. The tag display flashes the highest priority alarm name current in the
database, and the corresponding loop is entered for inspection, whether or not it is in
the main display. (If no alarm exists anywhere — ALM button LED unlit — NoAlm
is displayed and you cannot enter loop mode.) Once in loop mode, you can press ▲ or
▼ to select another loop for inspection if required; only loops in alarm are accessed.
2 Press ALM again to display the name of the block with the highest priority alarm in
the entered loop. BLOCK appears in the units display. (The units display will show
NoAlm if the loop has since cleared itself of alarms, and you remain in loop mode. In
this case you can select another loop in alarm using ▲ or ▼.)
3 Press ALM again. The tag display shows the alarm name within the block. The units
display shows SubFd, and the 5-digit display indicates UnAcd if the alarm is unac-
knowledged, or is blank if acknowledged.
4 Press ALM again to enter Alarm Acknowledge mode, indicated by AlAck in the units
display. To acknowledge the alarm, press ▲ or ▼.
5 Press ALM again to return to Loop Alarm Inspect mode.
Quitting alarm inspection modes

Pressing R, A, M, or SP-W immediately reverts the T640 to standard operation. A time-
out (in the T600 block) can also be set for automatic reversion after a defined period of no
button activity.

ALM button User interface
ALM
Enter ALARM INSPECT mode
Select other LOOP in alarm

LOOP
ALM
Select other BLOCK in alarm

BLOCK
ALM
HighAbs
Select other Alarm SUBFIELD in alarm

Hardware Combined LowAbs
SubFd
UnAcd
ALM
Hardware Hardware
AlAck AlAck
UnAcd ACKNOWLEDGE Alarm
ALM ALM
Figure 4-3 Alarm inspect button functions — ALM

User interface Security key
SECURITY KEY
Access to T640’s database via the INS pushbutton is protected by the T950 infrared-oper-
ating security key. (Using INS is described in an earlier section: Database access.)
Key parameters
Each key is factory-programmed with three parameters whose values are marked on the
key label. There is also a space for entering the keyholder’s name. The parameters are:
■ Access. Specifies how much of the database is accessible to the keyholder. Full
accesses all parameters; Partial accesses the limited default set of parameters specific
to each function block (or a set defined during strategy configuration in LINtools).
Note that the T600 block’s NoKeyFul and NoKeyPrt parameters if set TRUE allow full
or partial access respectively without needing a security key.
■ Area. Specifies by an area number (1 - 8) what databases are accessible to the key-
holder. The area number must match the T600 block’s AreaNo parameter to gain ac-
cess (except when AreaNo is zero, allowing any key access the database). A key can
also have an Area of zero, giving it access only to zero-AreaNo databases.
■ ID Code. Identifies each key with a unique 13-bit number (0 - 8191). Every time
the key is used to change a database, a record is logged in a file that includes all the
key’s parameters. This means that all changes are traceable to a particular keyholder.
(See Chapter 6, Changes logfile, for details)
Using the key

Figure 4-4 shows the T950 security key.
Press to operate
Red battery-test
LED
Infrared LED
Figure 4-4 Security key — operation
1 Press INS on the front panel. If no key is needed for access, loop access mode is im-
mediately entered and LOOP shows in the units display. Otherwise, No Key appears
in the tag display and you proceed to step 2.

Battery replacement User interface
2 Hold the key about 15cm from T640’s front-panel, aiming the infrared LED at the
OUT-Y legend to the left of the output bargraph (see Figure 4-1). The IR sensor is
here behind the fascia. Press INS, then squeeze the key briefly to click the internal
switch. If the security key is valid the tag display replies with LOOP, and loop access
mode is entered. Invalid keys display Bad Key.
NOTE. The battery-test LED on the case should glow when the switch is
pressed, indicating a healthy key battery. If not, replace the battery (described be-
low).
While the T640 is in INSpect mode the key is not needed. But if no pushbuttons are
pressed for a time specified by the T600 block’s TimeOut parameter, the fascia reverts
to the normal display. Re-entering INSpect mode then needs a security key again.
Battery replacement
Caution
Observe anti-static precautions when handling the security key with its lid open.
Replace the battery if the battery-test LED fails to light when the key is operated, and at
least every two years. Use a 12V alkaline manganese battery, e.g. Duracell™ MN21,
Panasonic™ RV08, or equivalent of overall length 27.5 - 28.5, diameter 9.62 - 10.62 (mm).
2. Hinge back lid Battery PCB Test LED

& remove
12V
1. Press below catch Tray Switch

Figure 4-5 Security key — battery replacement
1 See Figure 4-5. Press just below the lid catch, hinge back the lid and remove it com-
pletely. The interior of the key is shown on the right of the figure.
2 Extract the battery and fit a replacement, ensuring correct polarity. This is marked on
the tray underneath the battery, and also on the printed circuit board. Test the new bat-
tery by pressing the switch. The battery-test LED should light.
3 Replace the lid by positioning it over the pair of hinges, then snapping it shut securely
over the lid catch.

Fixed-function strategies
Chapter 5 FIXED-FUNCTION STRATEGIES
This chapter describes the four preconfigured ‘fixed-function’ control strategies supplied
with your T640 in its ROM area.
USING THE STRATEGIES

With the fixed-function T640 you do not have to create your control strategies from
scratch. Instead, you just load and run one of the pre-configured fixed-function strategies
stored in the instrument’s ROM. Once a fixed-function strategy is loaded you can, di-
rectly via the front panel, alter any default parameter values to suit your plant require-
ments, then save the customised database for future use (via the T600 block’s FullSave or
PartSave parameters). Accessing the database is described in Chapter 4, User interface.
The tutorial in Chapter 3 also gives you some practice at editing and saving the parameter
values of a fixed-function strategy via the front panel.
Instead of customising a fixed-function strategy from the front panel, you can use the PC
Windows-based Fixed-Function Parameterisation Tool (FFPT) to alter selected parameter
values. Software and operating instructions for the FFPT, and also for the file-handling
package LINfiler, are found in another section of this Product Manual. You use LINfiler to
download your parameterised databases to the T640, and for several other useful filing op-
erations.
You can also create your own entirely new ‘pre-configured’ strategies, loadable via the
motherboard DIL switches in the same way as the regular fixed-function strategies. This
is described later in the section, User-created standard strategies.
SUMMARY OF THE STRATEGIES

The fixed-function strategies are supplied in ROM in a compressed — ‘packed’ — format,
in files called name.FFn, where name is the strategy database name and n is the number
that must be set up on switches 6, 7, and 8 of SW2 to select the strategy (n = 1 to 4). The
T640 ‘unpacks’ a .FFn file to create a regular .DBF file with the same root filename, ready
to be downloaded to RAM and run. Table 5-1 summarises the fixed-function strategies.
n Name Summary
1 SINGLE A single loop controller
2 DUAL A dual loop controller
3 DUAL_CS A dual loop controller internally pre-wired in cascade
4 DUAL_RT A dual loop controller with ratio station
Table 5-1 Summary of the fixed-function strategies supplied in ROM as .FFn files

CREATING YOUR OWN ‘FIXED-FUNCTION’ STRATEGIES

To convert any strategy residing in EEPROM — filename.DBF — into a switch-selectable
‘fixed-function’ strategy #n, you must create a dummy file called filename.FFn and store it
in EEPROM (via the LINfiler utility) in place of the original strategy compressed file.
The dummy .FFn file can be empty, as its only function is to link n to the chosen root
filename.
When you select strategy #n via the motherboard DIL switches (Figure 5-1 reminds you
how to do this) your custom strategy will load and run. The method works because the
T640 does not attempt to unpack (decompress) the dummy .FFn file provided the corre-
sponding .DBF file already exists in EEPROM.
RUNNING A DEFAULT FIXED-FUNCTION STRATEGY

Running a default — as supplied in compressed format — fixed-function strategy from
ROM is a particular case of powering up the T640 and running any other strategy. (For a
more complete picture of what happens when you power-up the instrument, refer to Chap-
ter 2 in the section Power-up routine.)
To run one of the fixed-function strategies:
1 Withdraw the T640 from its sleeve (taking the necessary anti-static precautions — see
Chapter 2) and set switches 6, 7, and 8 of switchbank 1 to the strategy number re-
quired. (Figure 5-1 reminds you of their location and how to set them.)
2 Set switch 3 of SW1 ON to enable a cold start. (Other SW1 switches: Switch 4 should
also be ON if you want warm start capability. Leave other switches as required for
your T640 configuration.)
3 Power up the T640. Assuming that the selected strategy was not previously being run
when power-down occurred, the T640 searches its EEPROM area for a .FFn file with
the same n-value as that specified by switches 6, 7, and 8. If it finds a matching file, it
uses this to establish the name of the required strategy. If no match is found in EEP-
ROM, the T640 then searches the ROM area. (If a match still cannot be found — i.e.
the .FFn file is missing — the T640 adopts an idle state and no database is run.)
4 Having determined the required filename, the T640 then checks if the corresponding
.DBF file is already in EEPROM. (It won’t be if this is the first time the strategy is
being used. If it were found, the database would be loaded directly to RAM and run.)
If not found, the T640 ‘unpacks’ the compressed .FFn file, loads it to RAM and runs
it. An ‘unpacking database’ message appears on the front panel while this happens.

1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8
ON ON
1 2 4
OFF
SW1
ON
1 2 3 4 5 6 7 8
off off off = No new strategy selected

on off off = Strategy #1 (single loop) selected
off on off = Strategy #2 (dual loop) selected
on on off = Strategy #3 (cascade) selected
off off on = Strategy #4 (ratio) selected
(other) = ERROR — invalid selection
Figure 5-1 SW1 switch settings for strategy selection
FIXED-FUNCTION STRATEGY DESIGN PRINCIPLES

The four fixed-function strategies have been designed to be as straightforward to config-
ure and use as possible:
■ All the control loops follow the same design with the same function blocks and the
same I/O allocations on each I/O site (see Table 5-2). The variations are kept to a
minimum and are clearly identified.
■ The number of parameters that must be set up is minimal.
■ All settable parameters have usable default values.
■ Partial access is available without a security key by default.
■ The only connections required to get something happening are the PV and the 3T
OUT terminals.

Running a standard strategy Fixed-function strategies
FIXED-FUNCTION STRATEGIES —
MOTHERBOARD CUSTOMER TERMINALS
Table 5-2 lists the fixed-function strategy motherboard terminal functions, for both the
MAINS and the DC options. Where relevant, the table also indicates the names of func-
tion blocks having parameters that affect the operation of the corresponding I/O.
Pin Assignment Description Blocks

1 Internal earth Do not connect these terminals externally!
2 Internal earth
L Mains live Live & neutral mains input terminals.
N Mains neutral (MAINS option motherboard only — blank in DC option.)
7 DC source 1 +ve DC option power input terminals. PRIMARY supply.
8 DC source 1 –ve (DC option motherboard only — blank in MAINS option.)
9 DC source 2 +ve DC option power input terminals. BACKUP supply.
10 DC source 2 –ve (DC option motherboard only — blank in MAINS option.)
11 RS422 TX+ Serial communication connections. SL661
12 RS422 TX– If RS485 is selected pins 11 and 12 are unused, & pins 14 and 15
13 RS422 (RS485) Gnd become RS485+ and RS485– respectively.
14 RS422 RX+ (RS485+) (See T640 User Guide for details on setting serial comms. switches & jumpers.)
15 RS422 RX– (RS485–)
16 Watchdog 1 Relay output whose contacts are closed in normal operation. USR_ALM
17 Watchdog 2 They open on power loss or CPU failure. They have been configured to also open on alarm.
18 Alarm 1 Relay output whose contacts are closed in normal operation. They open on power
19 Alarm 2 loss or CPU failure. They also open if any alarm of priority 11 to 15 occurs.
20 ALIN Gnd ALIN peer-to-peer communications connections.
21 ALIN Phase A Connections should be made: Gnd to Gnd, Phase A to Phase A,
22 ALIN Phase B and Phase B to Phase B.
Table 5-2 Motherboard terminal assignments (MAINS & DC options)

Fixed-function strategies Design principles
STRATEGY #1 — SINGLE CONTROL LOOP

Strategy #1 is a single-loop controller with a repeat time of about 160ms per scan. Figure
5-2 shows a ‘P & I’ diagram for the strategy, involving a flow-control valve and an orifice
plate flow sensor, by way of example.
Local
setpoint
PV
3-term
output

Customer terminals Fixed-function strategies
Strategy #1 schematic
Figure 5-3 shows schematically the main function blocks in the strategy, the principal sig-
nal flows between them, and their associated customer terminals. Details of each terminal
and block are given in the tables that follow.
LOOP 1 INPUT RE-

area TRANSMITTED
OUTPUT
SWS_1.W Field1.Bit6
TX PSU+ 1C Transmitter area
V power
TX PSU– 1D supply PVOP1
PID CONTROL analogue 1M PV/SP OUT
area output
PV__1 block
analogue
PV 1E input FALSE
block SETP1 PV
setpoint CONTROL
TRIM1 block SP
analogue TRUE
OUTPUT
SP TRIM 1H input area
block
3TRM1 OUTP1 1A 3T OUT+
RSP_1 3-term analogue 4-20mA
analogue block output
REM SP 1F input block 1B 3T OUT–
block
TRCK1 MANS1 OP__1

analogue manual analogue
TRACK 1J input output 1L 3T OUT (0-10V)
station
block block block
COMP EN(0) 1P PROCESS

REM SP EN(1) 1Q DIN_1 ALARM
digital OUTPUT area 1T HI ALM OUT(0)
input Alarm
TRACK EN(1) 1R block DOP_1 outputs
digital
1U LO ALM OUT(0)
HOLD EN(1) 1S output
block 1V REM AUT OUT(0) Cascade
control
1W HOLD+MAN OUT(0) interlocks
NOTE SYSTEM ALARM LOOP 4

(0) or (1) after a terminal designation USR_ALM OUTPUT area
denotes that the designated state is asserted
when the signal is low or high, respectively.
alarm T60_** Watchdog 16 WATCHDOG 1
collection root
block block relay 17 WATCHDOG 2
Examples Priority (= 2)
TRACK EN(1) means that track mode is 18 ALARM 1
enabled by a high input. Alarms of priority ≥ 11
Alarm
For HI ALM OUT(0), a low output signifies a relay 19 ALARM 2
high absolute or high deviation alarm.
Strategy #1 I/O customer terminals

Strategy #1 uses a single I/O board located in site 1 of the T640, accessible via customer
terminals 1A to 1Z. Table 5-3 lists these terminations and their functions, and also where
relevant the names of function blocks having parameters that affect the operation of the
corresponding I/O.

Fixed-function strategies Strategy #1

1A 3T OUT +VE Isolated 4-20mA output signal. This is the control output, limited by the SWS_1
1B 3T OUT –VE manual station block MANS1.
1C TX Power Supply+ Isolated 24 volt transmitter power supply.
1D TX Power Supply–
1E PV Process variable voltage input. PV__1
1F REM SP Remote Setpoint voltage input. If the remote setpoint input is broken or not RSP_1
connected the loop reverts to its local setpoint. (Not Strategy #4)
RAT TRIM Ratio trim input. (Strategy #4 only — see under Strategy #4 — Ratio control for details) TRIM3
1G Analogue Gnd Reference ground for analogue signals
1H SP TRIM Setpoint trim voltage input TRIM1
RATIO BIAS Ratio bias input. (Strategy #4 only — see under Strategy #4 — Ratio control for details)
1J TRACK The control output is forced to this value if the TRACK EN (1) signal is high. TRCK1
1K Analogue Gnd Reference ground for analogue signals
1L 3T OUT Control output signal as a voltage OP__1
SWS_1
1M PV/SP OUT Retransmitted process variable or setpoint output as a voltage. PVOP1
Process variable is the default. SWS_1
1N Analogue Gnd Reference ground for analogue signals
1P COMP EN(0)* When high this digital input disables parameter changes via the comms links. DIN_1
It does not prevent parameters being read. This input does not affect MODBUS.
1Q REM SP EN(1) When high this digital input allows the remote setpoint to be selected from the DIN_1
front panel provided a signal is connected to REM SP.
1R TRACK EN(1) When high this digital input forces the control output to follow the TRACK input DIN_1
1S HOLD EN(1) When high this digital input forces the control output to freeze. DIN_1
1T HI ALM OUT(0) This digital signal goes low if the controller is in high absolute alarm DOP_1
or high deviation alarm
1U LO ALM OUT(0) This digital signal goes low if the controller is in low absolute alarm DOP_1
or low deviation alarm
1V REM AUT OUT(0) This digital output goes low if the controller is not in Auto with its remote setpoint DOP_1
selected. In cascade this signal should be connected from the slave to the
TRACK EN(1) of the master to allow bumpless transfer from local control to cascade.
It is also necessary to connect the retransmitted process variable, PV/SP OUT, of
the slave to the TRACK input of the master.
1W HOLD+MAN OUT(0) This digital output goes low if the controller is in Hold or Manual modes. DOP_1
In cascade this signal should be connected from the master to the REM SP EN(1)
of the slave to allow procedureless changes of mode. It also ensures that if the
master is removed that the slave goes into local control.
1X Ext Supply In The digital outputs pull to 15V. If 24V is connected to this pin, the digital outputs
24 volts pull up to 24V. If not used as an input, this pin may be used as a low-current 15V source to
drive inputs via relays or opto-couplers.
1Y Digital Gnd Reference ground for digital signals.
1Z Digital Gnd Reference ground for digital signals.
*(0) or (1) denotes bit asserted when low or high, respectively
Table 5-3 Site 1 I/O customer terminal assignments

Strategy #1 Fixed-function strategies
Strategy #1 function blocks and parameters

This strategy has two ‘user tasks’ — seen as LOOP 1 and LOOP 4 in the tag display —
that you can access via the INS pushbutton to configure their function blocks. The param-
eters in Loop 1 deal with configuration of the control loop itself, and those in Loop 4
cover system alarms and general instrument setup.
When you come to configure these parameters you will find the setup sheets helpful, be-
cause they list the default values of all fields, and include a spare column for you to record
your customised values where required. You may want to use photocopies of the printed
setup sheets as your working documents. The setup sheets for all strategies are found un-
der Setup sheets — all strategies on page 5-32.
Loop 1
Table 5-4 lists the Loop 1 parameters for strategy #1, together with explanations of their
functions.
NOTE. The order of the blocks in the table may not match their order of appear-
ance when you access them via the INS button.
Block Field Subfield Description

SL661 This block needs attention only if Bisync communications are to be used.
Instr_No Slave address of the control loop’s 6366 emulation on the Bisync communications bus.
SWS_1 This is a set of optional switches for setting up the loop
W Field1
Bit0 This defines the power up mode.
TRUE: the loop goes into manual on power up with ‘zero’ output*.
FALSE: the loop maintains its last mode and output on power up. ‘Zero’ means low electrical output
irrespective of any ranging or loop inversion.
Bit1 On PV fail the loop will go from AUTO into FORCED MANUAL.
This bit determines the action of the control output.
TRUE: ‘Zero’ output will be forced
FALSE: the last output will be maintained.
(‘Zero’ means low electrical output — 0V or 4mA — irrespective of any ranging or loop inversion.)
Bit2 TRUE inverts the output action, and hence the control action, after the manual station.
100% OP ≡ 4mA; 0% OP ≡ 20mA. This should be set TRUE if the actuator has reverse control ac-
tion for safety reasons. This bit affects both the 4-20mA and voltage control outputs. It does not affect
PV/SP OUT.
Bit3 This inverts the control action before the manual station. It does not affect the relationship between
the output reading and the true electrical output. This may be set true to reverse the action of the
loop.
Bit4 This selects On-Off control. See also 3TRM1.Deadband
Bit5 FALSE: the local setpoint will remain unchanged.
TRUE: the local setpoint will track the process variable if the controller is not in AUTO. Note: the
local setpoint will always track the remote setpoint when remote is selected.
*NB. If the HOLD EN(1) input is high at power-up, hold mode wins and the last output is maintained, despite Bit0’s being TRUE.
continued…

…continued
Bit6 FALSE: the second analogue output will be the retransmitted PV
TRUE: the second analogue output will be the retransmitted SP
Bit7 TRUE: Inverse ratio setting is used.
Normal: loop1 SP = loop2 PV / ratio setpoint; Inverse: loop1 SP = loop2 PV * ratio setpoint
Loop1 only - Ratio controller only
Bit8 TRUE: Mask R push-button
Bit9 TRUE: Mask A push-button
BitA TRUE: Mask M push-button
BitB TRUE: loop tag is FIC-001. Note: BitC has priority over BitB, BitD has priority over BitC and BitB etc.
Also loop 2 tags are FIC-002 etc. (If none set, tag defaults to LOOP 1 or LOOP 2.)
BitC TRUE: loop tag is LIC-001
BitD TRUE: loop tag is PIC-001
BitE TRUE: loop tag is TIC-001
BitF TRUE: loop tag is AIC-001
RSP_1* This block processes the remote setpoint input. Status.BrkDtctd is used in conjunction with the input
REM SP EN(1) to enable the remote setpoint. If the remote setpoint input is broken the loop reverts to
its local setpoint. If no remote setpoint is required all parameters in this block can be left as default.
Filter A first order filter with the time constant set will be applied to the input.
HR_in The input voltage representing high range
LR_in The input voltage representing low range
Options Only options believed relevant are described. Some options have defaults relevant to the I/O hard-
ware and should not be changed.
Invert TRUE maps HR_in to SETP1.LR_SP and LR_in to SETP1.HR_SP
Sqrt TRUE applies a square root function to the input
DIN_1 This block processes the digital inputs
Invert This field inverts the sense of the digital inputs on a bit by bit basis. Bit4 to Bit7 are not supported by
the hardware. Setting them will have no effect.
Bit0 TRUE inverts COMP EN(0) If this input is unused do not alter the default. If this input is used it will be
normal to invert its action so that a high input is required to enable parameter changes over the
communication networks.
Bit1 FALSE inverts REM SP EN(1) It should not be necessary to alter the default
Bit2 TRUE inverts TRACK EN (1) It should not be necessary to alter the default
Bit3 TRUE inverts HOLD EN(1) If this input is unused do not alter the default. If this input is used it will be
normal to invert its action.
PV__1 This block processes the process variable input. Alarms.Combined will cause the controller to go into
Forced Manual if an alarm with non-zero priority occurs. See SWS_1.W Field1.Bit0.
RomChar This is used to select input linearisation. The common thermocouple and resistance thermometer in-
puts are available.
*The RSP_1 block is absent from Strategy #4 (ratio controllers)

continued…

…continued
Alarms Although other alarms than those listed below are available, their priority should left at 0. Process
alarms may be set in SETP1. The alarms listed below should be left at the priority set unless there is a
reason to change them. A reason to change them might be to stop individual alarms affecting the
Watchdog relay, or to make alarm acknowledgement necessary (priority ≥6).
Note: if a zero priority is set, the alarm condition will no longer select Forced Manual.
Hardware (Default = 2)
OutRange (Default = 2)
OCctdel (Default = 2)
Invert TRUE maps HR_in to SETP1.LR_SP and LR_in to SETP1.HR_SP.
TRUE will also have the effect of inverting the control loop.
TRIM1 This input provides a trim to the setpoint. This trim input in engineering units is added to the setpoint
whether it is local or re mote. If no trim is required all parameters in this block can be left as default.
MODE This should be left at MANUAL if a manual trim or no trim are required. Set this input to AUTO if a
trim is to be provided as an input signal, SP TRIM
PV If MODE is set to MANUAL this input may be used to manually input a setpoint trim.
HR This sets the high range in engineering units. HR_in maps to HR.
Because trim works in engineering units HR and LR are used to scale the trim input against SETP1
HR_SP and LR_SP.
LR This sets the low range in engineering units. LR_in maps to LR.
It would not be unusual for LR to be the same value as HR but negative to give a symmetrical trim.
Filter A first-order filter with the time constant set applied to the input.
Invert TRUE maps HR_in to LR and LR_in to HR
SETP1 This block provides all the setpoint processing and alarms.
HR_SP The high range of the process variable and setpoint in engineering units. The block is internally con-
nected so that the process variable and remote setpoint share the same ranges as HR_SP and LR_SP
LR_SP The low range of the process variable and setpoint in engineering units.
HL_SP This sets a high limit for the setpoint including any trim whether the setpoint is local or remote.
LL_SP This sets a low limit for the setpoint including any trim whether the setpoint is local or remote.
HL_SL This sets a high limit for the local setpoint.
LL_SL This sets a low limit for the local setpoint.
continued…

…continued
Alarms These are the process alarms of the control loop. Note: Priority 0 disables the alarm completely. An
alarm with 0 priority no longer affects the digital output: HI ALM OUT(0) or LO ALM OUT(0)
Priority 6-15 need to be acknowledged. Priority 11-15 open the Alarm relay.
Alarms with priority set equal to USR_ALM.Priority open the Watchdog relay
HighAbs PV exceeds HAA
LowAbs PV is less than LAA
HighDev PV-SP exceeds HDA
LowDev SP-PV exceeds LDA
HAA High absolute alarm setting
LAA Low absolute alarm setting
HDA High deviation alarm setting
LDA Low deviation alarm setting
Dis_DP Sets the number of digits displayed to the right of the decimal point. This parameter is for display
purposes only and has no effect on the ranging.
DOP_1 This block processes the digital outputs. The default values in this block need not normally be al-
tered.
Invert This field inverts the sense of the digital outputs on a bit by bit basis. Bit4 to Bit7 are not supported
by the hardware. Setting them will have no effect.
Bit0 FALSE inverts HI ALM OUT(0)
Bit1 FALSE inverts LO ALM OUT(0)
Bit2 TRUE inverts REM AUT OUT(0)
Bit3 TRUE inverts HOLD+MAN OUT(0)
PVOP1 This block processes the retransmitted process variable or setpoint. See SWS_1.W Field1.Bit5
HR_out The output voltage representing high range
LR_out The output voltage representing low range
3TRM1 This block performs PID (‘3-term’) control. The default values of XP, TI, and TD allow a measure of
control, but should be set to more appropriate values for your application.
TimeBase This sets the time units for TI and TD
XP This set the proportional band for control
TI This sets the integral time constant
TD This sets the derivative time constant
Deadband This sets the hysteresis band if On/Off control is selected. See SWS_1.W Field1.Bit3. The value set
is applied symmetrically above and below the setpoint.
TRCK1 This input processes the TRACK input.
If TRACK is not required all parameters in this block can be left as default.
MODE If the track input is being provided as an input signal, this should be left AUTO. Selecting MANUAL
will cause the control output to adopt the value set in PV if TRACK EN(1) goes high.
PV If MODE is set to MANUAL this input may be used to manually input a TRACK value.
HR_in The input voltage representing 100% output
LR-in The input voltage representing 0% output
continued…
…continued
MANS1 This block provides output processing from 3TRM1. The output range is fixed at 0-100%.
HL_OP High limit for the control output in %
LL_OP Low limit for the control output in %
OP__1 This block processes the control voltage output. It follows the 4-20mA output. Output inversion can-
not be performed by reversing the values in HR_out and LR_out. SWS_1.W Field1.Bit1 does this.
HR_out The output voltage representing 100% (0% if SWS_1.W Field1.Bit2 is TRUE)
LR_out The output voltage representing 0% (100% if SWS_1.W Field1.Bit2 is TRUE)
Table 5-4 Loop 1 parameters

Loop 4
functions.

USR_ALM This block controls watchdog relay output.
Priority (Range: 0-15) The priority of the alarms that are required to open the relay must match this setting.
T60_** This block contains the basic options of the controller as an instrument. The ** in the name will be
replaced by the node number in hex when the strategy is loaded. E.g. C6
Options Many of the subfields have no relevance to this application. They are included here because they
appear during use of the INS button.
FPdis1 Leave as default (FALSE)
FPdis2 Leave as default: TRUE in the single loop controllers, FALSE in the dual loop controllers
FPdis3 Leave as default: TRUE in all but ratio controller, FALSE in ratio controller
FPdis4 Leave as default (TRUE)
NoKeyPrt The default (TRUE) allows access to the normally settable parameters without using the security key.
This should normally be set to FALSE before the controller is put on to plant.
NoKeyFul This should be left as default (FALSE). Setting this TRUE allows access to all the parameters in the
controller without the use of a full access key.
LEDtest If set TRUE all the LEDs on the front panel light. It resets itself to FALSE
CommsDis This is internally wired and may be used only for reading the state of the ALIN and Bisync communi-
cations. TRUE: parameter ‘writes’ inhibited; FALSE: communications fully enabled
FullSave If set TRUE the parameters in the running database are saved to file. These parameters will be used
on cold start. This or PartSave should be used after configuration to ensure the set up is not lost. It
resets itself to FALSE
PartSave This is the same as FullSave except local setpoints, control outputs and control modes are not saved.
This allows tuning parameters to be set up and saved during commissioning without overwriting the
start up conditions.
BinSpd1 BinSpd1 FALSE FALSE TRUE TRUE
Bisync baud rate:
BinSpd2 BinSpd2 FALSE TRUE FALSE TRUE
Baud rate = 9600* 4800 1200 300 *default
Protectd Leave as default (TRUE)
E2Form1 This and E2Form2 when used together in sequence will reformat the EEPROM filing system. The se-
quence is relatively complex to make it unlikely that the EEPROM is reformatted accidentally.
E2Form2 (See previous)

STRATEGY #2 — DUAL CONTROL LOOP

Strategy #2 is a dual-loop controller. The difference between the single loop (strategy #1)
and the dual loop controllers is simply the inclusion of the second loop. This loop is iden-
tical to the first, except that its I/O is assigned to site 2 of the T640 (terminals 2A to 2Z).
Note that terminal 2P is unused as COMP EN(0), because 1P is used to disable communi-
cations for the whole instrument.
One loop or two?

If only one loop is needed the single loop controller should be chosen in preference to the
dual for the following reasons:
■ With only one loop implemented the single loop has a faster update rate — approxi-
mately 160ms. The update rate of each loop in the dual loop controller is around
300ms.
■ If the second loop in the dual loop strategy is not connected to anything, Loop 2 proc-
ess variable alarms will appear and remain permanently annunciated.
Figure 5-4 shows a ‘P & I’ diagram for the strategy, involving flow-control valves and ori-
fice plate flow sensors, by way of example.
Local
setpoint
PV
3-term
output
Local
setpoint
PV
3-term
output

LOOP 1 INPUT RE-

area TRANSMITTED
OUTPUT
SWS_1.W Field1.Bit6
V power
supply PVOP1
TX PSU– 1D PID CONTROL analogue
output
1M PV/SP OUT
PV__1 area
block
analogue
PV 1E input FALSE
block SETP1 PV
setpoint CONTROL
TRIM1 block SP
analogue TRUE
OUTPUT
block
block
TRCK1 MANS1 OP__1

TRACK 1J input station output 1L 3T OUT (0-10V)
block block block
COMP EN(0) 1P PROCESS

DIN_1
ALARM
REM SP EN(1) 1Q digital OUTPUT area 1T HI ALM OUT(0)
Alarm
input outputs
TRACK EN(1) 1R block
DOP_1 1U LO ALM OUT(0)
digital
HOLD EN(1) 1S output
control
LOOP 2 RE-
INPUT
area TRANSMITTED
OUTPUT
SWS_2.W Field1.Bit6
V power
TX PSU– 2D supply PVOP2
PID CONTROL analogue
2M PV/SP OUT
area output
PV__2 block
analogue
PV 2E input FALSE
block SETP2 PV
setpoint CONTROL
TRIM2 block SP
analogue TRUE
OUTPUT
block
block
TRCK2 MANS2 OP__2

block block block
PROCESS
REM SP EN(1) 2Q DIN_2
digital ALARM
TRACK EN(1) 2R input OUTPUT area 2T HI ALM OUT(0)
Alarm
block outputs
HOLD EN(1) 2S digital
output
control
SYSTEM ALARM LOOP 4

USR_ALM OUTPUT area
collection root
Priority (= 2)
Alarm 18 ALARM 1
Alarms of priority ≥ 11
relay 19 ALARM 2


Strategy #2 uses a pair of I/O boards located in sites 1 and 2 of the T640, accessible via
customer terminals 1A to 1Z (site 1) and 2A to 2Z (site 2). Site 1 terminals are identical
to those given for strategy #1 (see Table 5-3 on page 5-7). Table 5-6 lists site 2 termina-
tions and their functions, and also where relevant the names of function blocks having pa-
rameters that affect the operation of the corresponding I/O.

2A 3T OUT +VE Isolated 4-20mA output signal. This is the control output. SWS_2
2B 3T OUT –VE
2C TX Power Supply+ Isolated 24 volt transmitter power supply.
2D TX Power Supply–
2E PV Process variable voltage input. PV__2
2F REM SP Remote Setpoint voltage input. If the remote setpoint input is broken or not RSP_2
connected the loop reverts to its local setpoint.
RAT TRIM Ratio trim input. (See under Strategy #4 — Ratio control for details) TRIM3
2G Analogue Gnd Reference ground for analogue signals
2H SP TRIM Setpoint trim voltage input TRIM2
2J TRACK The control output is forced to this value if the TRACK EN (1) signal is high. TRCK2
2K Analogue Gnd Reference ground for analogue signals
2L 3T OUT Control output signal as a voltage OP__2
SWS_2
2M PV/SP OUT Retransmitted process variable or setpoint output as a voltage. PVOP2
Process variable is the default. SWS_2
2N Analogue Gnd Reference ground for analogue signals
2P (Unused)
2Q REM SP EN(1) When high this digital input allows the remote setpoint to be selected from the DIN_2
front panel provided a signal is connected to REM SP.
2R TRACK EN(1) When high this digital input forces the control output to follow the TRACK input DIN_2
2S HOLD EN(1) When high this digital input forces the control output to freeze. DIN_2
2T HI ALM OUT(0) This digital signal goes low if the controller is in high absolute alarm DOP_2
or high deviation alarm
2U LO ALM OUT(0) This digital signal goes low if the controller is in low absolute alarm DOP_2
or low deviation alarm
continued…

…continued
2V REM AUT OUT(0) This digital output goes low if the controller is not in Auto with its remote setpoint DOP_2
selected. In cascade this signal should be connected from the slave to the
TRACK EN(1) of the master to allow bumpless transfer from local control to cascade.
It is also necessary to connect the retransmitted process variable, PV/SP OUT, of
the slave to the TRACK input of the master.
2W HOLD+MAN OUT(0) This digital output goes low if the controller is in Hold or Manual modes. DOP_2
In cascade this signal should be connected from the master to the REM SP EN(1)
of the slave to allow procedureless changes of mode. It also ensures that if the
master is removed that the slave goes into local control.
2X (Unused)
2Y Digital Gnd Reference ground for digital signals.
2Z Digital Gnd Reference ground for digital signals.
Table 5-6 Site 2 I/O customer terminal assignments

This strategy has three ‘user tasks’ — seen as LOOP 1, LOOP 2, and LOOP 4 in the tag
display — that you can access via the INS pushbutton to configure their function blocks.
The parameters in Loops 1 and 2 deal with configuration of the respective control loops
themselves, and those in Loop 4 cover system alarms and general instrument setup.
When you come to configure these parameters you will find the setup sheets helpful, be-
cause they list the default values of all fields, and include a spare column for you to record
your customised values where required. You may want to use photocopies of the printed
setup sheets as your working documents. The setup sheets for this strategy are found un-
der Setup sheets — all strategies, on page 5-32.
Loop 1
Loop 1 parameters are identical to those given for strategy #1 (see Table 5-4 on page 5-8).
Loop 2
functions.


SWS_2 This is a set of optional switches for setting up the loop
W Field1
Bit0 This defines the power up mode.
TRUE: the loop goes into manual on power up with ‘zero’ output*.
FALSE: the loop maintains its last mode and output on power up.
‘Zero’ means low electrical output irrespective of any ranging or loop inversion.
Bit1 On PV fail the loop will go from AUTO into FORCED MANUAL this bit determines the action of the
control output
TRUE: ‘Zero’ output will be forced
FALSE: the last output will be maintained.
‘Zero’ means low electrical output irrespective of any ranging or loop inversion.
Bit2 TRUE inverts the output action, and hence the control action, after the manual station.
100% OP ≡ 4mA; 0% OP ≡ 20mA. This should be set TRUE if the actuator has reverse control ac-
tion for safety reasons. This bit affects both the 4-20mA and voltage control outputs. It does not affect
PV/SP OUT.
Bit3 This inverts the control action before the manual station. It does not affect the relationship between
the output reading and the true electrical output. This may be set true to reverse the action of the
loop.
Bit4 This selects On-Off control. See also 3TRM2.Deadband
Bit5 FALSE: the local setpoint will remain unchanged.
TRUE: the local setpoint will track the process variable if the controller is not in AUTO. Note: the
local setpoint will always track the remote setpoint when remote is selected.
Bit6 FALSE: the second analogue output will be the retransmitted PV
TRUE: the second analogue output will be the retransmitted SP
Bit7 TRUE: Inverse ratio setting is used.
Normal: loop1 SP = loop2 PV / ratio setpoint; Inverse: loop1 SP = loop2 PV * ratio setpoint
Loop1 only - Ratio controller only
Bit8 TRUE: Mask R push-button
Bit9 TRUE: Mask A push-button
BitA TRUE: Mask M push-button
BitB TRUE: loop tag is FIC-001. Note: BitC has priority over BitB, BitD has priority over BitC and BitB etc.
Also loop 2 tags are FIC-002 etc.
BitC TRUE: loop tag is LIC-001
BitD TRUE: loop tag is PIC-001
BitE TRUE: loop tag is TIC-001
BitF TRUE: loop tag is AIC-001
*NB. If the HOLD EN(1) input is high at power-up, hold mode wins and the last output is maintained, despite Bit0’s being TRUE.
continued…

…continued
RSP_2 This block processes the remote setpoint input. Status.BrkDtctd is used in conjunction with the input
REM SP EN(1) to enable the remote setpoint. If the remote setpoint input is broken the loop reverts to
its local setpoint. If no remote setpoint is required all parameters in this block can be left as default.
Invert TRUE maps HR_in to SETP2.LR_SP and LR_in to SETP2.HR_SP
DIN_2 This block processes the digital inputs
Invert This field inverts the sense of the digital inputs on a bit by bit basis. Bit4 to Bit7 are not supported by
the hardware. Setting them will have no effect.
Bit0 (Unused)
Bit1 FALSE inverts REM SP EN(1) It should not be necessary to alter the default
Bit2 TRUE inverts TRACK EN (1) It should not be necessary to alter the default
Bit3 TRUE inverts HOLD EN(1) If this input is unused do not alter the default. If this input is used it will be
normal to invert its action.
PV__2 This block processes the process variable input. Alarms.Combined will cause the controller to go into
Forced Manual if an alarm with non-zero priority occurs. See SWS_2.W Field1.Bit0.
RomChar This is used to select input linearisation. The common thermocouple and resistance thermometer in-
puts are available.
Alarms Although other alarms than those listed below are available, their priority should left at 0. Process
alarms may be set in SETP2. The alarms listed below should be left at the priority set unless there is a
reason to change them. A reason to change them might be to stop individual alarms affecting the
Watch Dog relay. Note: if a zero priority is set the alarm condition will no longer select Forced
Manual.
Hardware (Default = 2)
OutRange (Default = 2)
OCctdel (Default = 2)
Invert TRUE maps HR_in to SETP2.LR_SP and LR_in to SETP2.HR_SP.
TRUE will also have the effect of inverting the control loop.
continued…

…continued
TRIM2 This input provides a trim to the setpoint. This trim input in engineering units is added to the setpoint
whether it is local or re mote. If no trim is required all parameters in this block can be left as default.
PV If MODE is set to MANUAL this input may be used to manually input a setpoint trim.
HR This sets the high range in engineering units. HR_in maps to HR.
Because trim works in engineering units HR and LR are used to scale the trim input against SETP1
HR_SP and LR_SP.
LR This sets the low range in engineering units. LR_in maps to LR.
It would not be unusual for LR to be the same value as HR but negative to give a symmetrical trim.
Filter A first order filter with the time constant set applied to the input.
Invert TRUE maps HR_in to LR and LR_in to HR
SETP2 This block provides all the setpoint processing and alarms.
HR_SP The high range of the process variable and setpoint in engineering units. The block is internally con-
nected so that the process variable and remote setpoint share the same ranges as HR_SP and LR_SP
LR_SP The low range of the process variable and setpoint in engineering units.
HL_SP This sets a high limit for the setpoint including any trim whether the setpoint is local or remote.
LL_SP This sets a low limit for the setpoint including any trim whether the setpoint is local or remote.
Alarms These are the process alarms of the control loop. Note: Priority 0 disables the alarm completely. An
alarm with 0 priority no longer affects the digital output: HI ALM OUT(0) or LO ALM OUT(0)
Priority 6-15 need to be acknowledged. Priority 11-15 open the Alarm relay.
Alarms of priority equal to USR_ALM.Priority will open the Watchdog relay.
HighAbs PV exceeds HAA
LowAbs PV is less than LAA
HighDev PV-SP exceeds HDA
LowDev SP-PV exceeds LDA
continued…

…continued
DOP_2 This block processes the digital outputs. The default values in this block need not normally be al-
tered.
Invert This field inverts the sense of the digital outputs on a bit by bit basis. Bit4 to Bit7 are not supported
by the hardware. Setting them will have no effect.
Bit0 FALSE inverts HI ALM OUT(0)
Bit1 FALSE inverts LO ALM OUT(0)
Bit2 TRUE inverts REM AUT OUT(0)
Bit3 TRUE inverts HOLD+MAN OUT(0)
PVOP2 This block processes the retransmitted process variable or setpoint. See SWS_2.W Field1.Bit5
HR_out The output voltage representing high range
LR_out The output voltage representing low range
3TRM2 This block performs PID control. The defaults for XP, TI and TD are provided only to allow control to
happen. These require setting to appropriate values.
TimeBase This sets the time units for TI and TD
XP This set the proportional band for control
TI This sets the integral time constant
TD This sets the derivative time constant
Deadband This sets the hysteresis band if On/Off control is selected. See SWS_2.W Field1.Bit3. The value set
is applied symmetrically above and below the setpoint.
TRCK2 This input processes the TRACK input.
If TRACK is not required all parameters in this block can be left as default.
MODE If the track input is being provided as an input signal, this should be left AUTO. Selecting MANUAL
will cause the control output to adopt the value set in PV if TRACK EN(1) goes high.
PV If MODE is set to MANUAL this input may be used to manually input a TRACK value.
HR_in The input voltage representing 100% output
LR-in The input voltage representing 0% output
MANS2 This block provides output processing from 3TRM2. The output range is fixed at 0-100%.
HL_OP High limit for the control output in %
LL_OP Low limit for the control output in %
OP__2 This block processes the control voltage output. It follows the 4-20mA output. Output inversion can-
not be performed by reversing the values in HR_out and LR_out. SWS_2.W Field1.Bit1 does this.
HR_out The output voltage representing 100% (0% if SWS_2.W Field1.Bit2 is TRUE)
LR_out The output voltage representing 0% (100% if SWS_2.W Field1.Bit2 is TRUE)
Loop 4
Loop 4 parameters are identical to those given for strategy #1 (see Table 5-5 on page
4-10).

STRATEGY #3 — DUAL CONTROL LOOP (CASCADE)

Strategy #3 is a dual-loop controller. The difference between it and strategy #2 is that the
two controllers are internally pre-wired for remote setpoint cascade operation with bump-
less transfer.
Figure 5-6 shows a ‘P & I’ diagram for the strategy in which — by way of example — the
outflow from a tank is controlled by the slave loop, according to a remote setpoint output
from the master loop. The master loop derives its output from a local setpoint and a meas-
ured variable from the tank (e.g. fluid level).
MASTER
Local
Loop 2
setpoint
PV
3T OUT
Interlocking
signals
REM SP
SLAVE Local
Loop 1 setpoint
PV
3T OUT

The purpose of the interlocking signals indicated in the Figure is to provide bumpless, pro-
cedureless transfer between modes of operation. Table 5-8 shows the pin assignments cor-
responding to these interlocks, with Loop 2 as the master controller and Loop 1 the slave.
For completeness the Figure also lists the 3T OUT to REM SP connection — not strictly
an ‘interlock signal’.
MASTER SLAVE
Pin Function Pin Function
2L 3T OUT 1F REM SP
2J TRACK 1M PV OUT
2W HOLD+MAN OUT(0) 1Q REM SP EN(1)
2R TRACK EN(1) 1V REM AUT OUT(0)
Table 5-8 Cascade interlocking signals — strategy #3
Note that Table 5-8 is given for information only. All the interconnections shown have
been made within the strategy in software, so you do not need to wire them externally.
Cascading a pair of loops

Although you don’t need to physically wire the interlock signals between Loops 1 and 2 if
you are using strategy #3 as supplied, you will find Table 5-8 useful if you want to cascade
a different pair of loops. As examples, you may want to cascade the disconnected pair of
loops supplied in strategy #2 (dual loop), or even two loops running in different instru-
ments.
NOTE. All Eurotherm Process Automation controllers have these interlocks

available.
In these cases you decide which loop is to be the master and which the slave, then wire-
link the customer terminals associated with each loop — as indicated in Table 5-8. Re-
member that the number prefix in customer terminal designations must match the I/O site
involved — e.g. 2L is the 3-term output for site 2 I/O, but 1L is the 3-term output for site
1 I/O, so you will have to interpret the table according to your I/O sites.

LOOP 2
Master SWS_2.W Field1.Bit6
RE-
MASTER TRANSMITTED
INPUT area
PID CONTROL OUTPUT
PV__2 area area
analogue
PV 2E input FALSE
PVOP2
SETP2 PV
block analogue
setpoint
output
2M PV/SP OUT
block SP
TRIM2 block
TRUE
analogue
SP TRIM 2H input
block 3TRM2
3-term
block
PROCESS
RSP_2
analogue ALARM
REM SP 2F input OUTPUT area 2T HI ALM OUT(0)
Alarm
block MANS2 O/Ps
manual digital
REM SP EN(1) 2Q station output
DIN_2 block
TRACK block 2V REM AUT OUT(0)
digital
HOLD EN(1) 2S input
VALUE
2W HOLD+MAN OUT(0)
block
Cascade
REMOTE control
SETPOINT interlocks
ENABLE
REMOTE
PROCESS ALARM
SETPOINT SWS_1.W Field1.Bit6
LOOP 1
OUTPUT area
1V REM AUT OUT(0)
Slave
RE-
DOP_1
1U LO ALM OUT(0) SLAVE TRANSMITTED
digital OUTPUT
output
PID CONTROL
block
1T HI ALM OUT(0) area area
FALSE
1W HOLD+MAN OUT(0) SETP1 PV PVOP1
setpoint analogue 1M PV/SP OUT
block SP output
TRUE block
INPUT area
TRIM1 3TRM1
analogue 3-term CONTROL
SP TRIM 1H input block OUTPUT
block area
PV__1 MANS1 OUTP1
manual
1A 3T OUT+
analogue analogue
PV 1E input station output
4-20mA
block block block 1B 3T OUT–
DIN_1
COMP EN(0) 1P digital
OP__1
analogue
TRACK EN(1) 1R input
output 1L 3T OUT (0-10V)
block
block
HOLD EN(1) 1S
SYSTEM ALARM LOOP 4

USR_ALM OUTPUT area
collection root
Priority (= 2)
Alarm 18 ALARM 1
Alarms of priority ≥ 11
relay 19 ALARM 2

Strategy #3 organisation
Master & slave
The strategy has been internally connected to make Loop 2 the master controller, and
Loop 1 the slave controller.
Blocks & connections

Strategy #3 is similarly-structured to strategy #2, but has the following additions that work
behind the scenes:
■ Two extra database interconnections are present —
3TRM1.Status.HiLimFrc to 3TRM2.Options.FrcHiLim
3TRM1.Status.LoLimFrc to 3TRM2.Options.FrcLoLim
These cause the master, Loop 2, to behave as if in output limit when the slave, Loop 1,
goes into output limit. This has the effect of inhibiting integral term windup in the
master controller, and gives faster return to control.
■ Range blocks have been added to re-range the ‘analogue’ internal connections be-
tween the loops. Loop 2’s output is still ranged 0-100% and loop 1’s PV and SP
ranges are chosen to represent engineering units. Note that these range blocks are not
accessible via the INS button for configuration.
Loop update rates

The loop update rates have been chosen to let the slave run faster than the master. The up-
date rate of Loop 1 is 220ms, and of Loop 2 is 420mS.
Strategy #3 — operator interface

Cascade control is selected by putting the slave Loop1 into Remote mode (press the R but-
ton) and putting the master Loop 2 into Auto mode (press A).
NOTE. If these conditions are not true, Loop 1 will be in the mode selected and
Loop 2 will be tracking it.
The sequence in which the modes are selected does not matter as the interlocking signals
ensure no illegal modes occur:
■ If Loop 1’s R button is pressed before Loop 2’s A button, Loop 1’s A indicator will
flash indicating the mode ‘Primed’. In operation, Primed is identical to Auto, except
that as soon as Loop 2 is put into Auto, Loop 1 goes into Remote.
■ If Loop 2’s A button is pressed before Loop 1’s R button, Loop 2’s A indicator will
light but the T indicator will remain lit indicating that Track is overriding Auto. When
Loop 1’s R button is pressed, Loop 2 is no longer forced to track and cascade control
begins.


customer terminals 1A to 1Z (site 1) and 2A to 2Z (site 2). These terminations and their
functions are almost the same as those for strategy #2, given in Tables 5-3 and 5-6.
The exceptions are that the following terminals have no function in the strategy —
■ Pin 1F, REM SP
■ Pin 1Q, REM SP EN(1)
■ Pin 2J, TRACK
■ Pin 2R, TRACK EN(1)
■ Pin 2P, COMP EN(0)

This strategy has three ‘user tasks’ — seen as LOOP 1, LOOP 2, and LOOP 4 in the tag
display — that you can access via the INS pushbutton to configure their function blocks.
The parameters in Loops 1 and 2 deal with configuration of the respective control loops
themselves, and those in Loop 4 cover system alarms and general instrument setup. The
three loops are almost the same as those of strategy #2, which were tabulated in Tables
5-4, 5-7, and 5-5.
The exceptions are that —
■ The block RSP_1 and its input REM SP, pin 1F, are present but have no function
■ The block TRCK2 and its input TRACK, pin 2J, are present but have no function.
When you come to configure these parameters you will find the setup sheets for this strat-
egy helpful, because they list the default values of all fields, and include a spare column
for you to record your customised values where required. You may want to use photocop-
ies of the printed setup sheets as your working documents. The setup sheets for this strat-
egy are found under Setup sheets — all strategies on page 5-32.

Fixed-function strategies Strategy #4 — Ratio pair
STRATEGY #4 — DUAL CONTROL LOOP (RATIO)

Strategy #4 is a dual-loop controller — Loops 1 and 2 — having in addition a ratio station
in Loop 3. All loop interconnections are internally pre-wired in the database.
Figure 5-8 shows a ‘P & I’ diagram for the strategy in which — by way of example — a
pair of flow rates are controlled to maintain a fixed ratio between them.
MASTER
Local
Loop 2
setpoint
PV
3T OUT
RATIO STATION Loop 3
Measured ratio display
Ratio setpoint trim

Divide by ratio setpoint
SLAVE Local
Loop 1 setpoint
Ratio bias
PV
3T OUT

Strategy #4 — Ratio pair Fixed-function strategies
LOOP 2 INPUT SWS_2.W Field1.Bit6 RE-

TRANSMITTED
Master area
PID CONTROL OUTPUT area
PV__2 area
PVOP2
analogue analogue
PV 2E input 2M PV/SP OUT
FALSE output
block SETP2 PV block
setpoint
TRIM2 block SP
analogue
SP TRIM 2H input
TRUE CONTROL
block OUTPUT area
RSP_2 3-term analogue
analogue 4-20mA
REM SP 2F block output
input block 2B 3T OUT–
block
TRCK2 MANS2 OP__2

block block block
REM SP EN(1) 2Q PROCESS

DIN_2
digital
ALARM
HOLD EN(1) 2S input OUTPUT area 2T HI ALM OUT(0)
Alarm
block outputs
DOP_2 2U
TRACK EN(1) 2R digital
LO ALM OUT(0)
Master’s output
PV block 2V REM AUT OUT(0) Cascade
control
LOOP 3 DCpl3
Calculate
measured T640
Ratio station Ratio SL filter
block SWS_1.W Field1.Bit7
PV ratio SP
PV
TRIM3 TRUE
SETP3 Derive Inverse Slave’s PV
analogue
RAT SP TRIM 1F input setpoint Slave’s PV SP
block REM SP Normal Ratio SP
block
FALSE
PROCESS ALARM
Slave’s Remote SP
LOOP 1
OUTPUT area
1V REM AUT OUT(0) Slave
DOP_1
1U LO ALM OUT(0)
digital RE-
output
block
1T HI ALM OUT(0) TRANSMITTED
OUTPUT
1W HOLD+MAN OUT(0)
area
SWS_1.W Field1.Bit6
PVOP1
INPUT area analogue
1M PV/SP OUT
output
PID CONTROL block
TRIM1 area
analogue
RATIO BIAS 1H input FALSE
block SETP1 PV
setpoint CONTROL
PV__1 block SP
analogue TRUE
OUTPUT
PV 1E input area
block
TRCK1 3-term analogue 4-20mA
TRACK 1J input block 1B 3T OUT–
block
COMP EN(0) 1P OP__1
DIN_1 analogue
REM SP EN(1) 1Q MANS1 output 1L 3T OUT (0-10V)
digital manual
input block
TRACK EN(1) 1R station
block block
HOLD EN(1) 1S

Strategy #4 organisation
Master, slave, & ratio station
The strategy has been internally connected to make Loop 2 the master controller, Loop 1
the slave, and Loop 3 the ratio station.
Normal & inverse ratios

The ratio value may be entered and displayed as the ratio of Loop 1’s PV to Loop 2’s PV,
or the other way round. See SWS_1.Bit7 in Table 5-4 on page 5-8.
Normal and inverse ratio are defined as follows:
■ Normal — Loop1 SP = Loop2 PV / ratio setpoint
■ Inverse — Loop1 SP = Loop2 PV * ratio setpoint
Modes
Loop 1 can to go into ratio mode for all operating modes of Loop2. However if Loop 2’s
process variable PV becomes invalid, Loop 1 reverts to Auto mode. Ratio control will
only resume once Loop 2’s PV has re-established and Loop 1’s R button is re-pressed.
With Loop 2 not used for control, the T640 can be used as a single loop controller with
ratio input.
Ratio setpoint trim

The ratio Setpoint trim input is customer terminal 1F, in place of the unused remote set-
point input for Loop 1. The function block RSP_1 does not exist
Ratio bias
The function of ratio bias is achieved through Loop 1’s SP TRIM. This input operates to
make the bias function as [Ratio + bias], or [(1/Ratio) + bias], depending on the ratio set-
ting option.
NOTE. Ratio bias does not perform the function [1/(Ratio + bias)].
Filtering
SETP2.PV is filtered before calculating the remote setpoint for SETP1. The filter is also
applied prior to the measured ratio calculation. The filter prevents open-loop disturbances
in Loop 2’s PV to affect the closed-loop performance of Loop 1.

Strategy #4 — Ratio pair Fixed-function strategies
Loop update rates

The update rate of each loop is 320ms.
Strategy #4 — operator interface

The ratio setpoint is adjusted by selecting Loop 3 and raising or lowering the setpoint.
Ratio control is achieved by pressing the R button when Loop 1 is selected. If Loop 1 is
not in Remote mode, the two loops will act independently, although the measured ratio is
still shown.

customer terminals 1A to 1Z (site 1) and 2A to 2Z (site 2). These terminals and functions
are almost the same as those for strategy #2, given in Tables 5-3 and 5-5. The exception is
terminal 1F, which is here the Ratio Trim input instead of the Remote Setpoint input.

This strategy has four ‘user tasks’ — seen as LOOP 1, LOOP 2, LOOP 3 and LOOP 4
in the tag display — that you can access via the INS pushbutton to configure their func-
tion blocks. The parameters in Loops 1 and 2 deal with configuration of the respective
slave and master control loops, those in Loop 3 deal with the ratio station, and those in
Loop 4 cover system alarms and general instrument setup. Loops 1, 2, and 4 are the same
as those of strategy #2, which were tabulated in Tables 5-4, 5-7, and 5-5.
Loop 3’s configurable blocks and parameters, associated with the ratio station, are listed in
Table 5-9 below.
When you come to configure these parameters you will find the setup sheets for this strat-
egy helpful, because they list the default values of all fields, and include a spare column
for you to record your customised values where required. You may want to use photocop-
ies of the printed setup sheets as your working documents. The setup sheets for this strat-
egy are found under Setup sheets — all strategies on page 5-32.

DCpl3 This block filters SETP2.PV before calculating the remote setpoint for SETP1. The filter is also applied
prior to the measured ratio calculation.
Filter First-order filter time constant.
continued…

…continued
TRIM3 This input provides a trim to the ratio setpoint. This trim input is added to the setpoint directly. If no
trim is required all parameters in this block can be left as default.
PV If MODE is set to MANUAL this input may be used to manually input a ratio setpoint trim.
HR This sets the high range: HR_in maps to HR. Because trim works by direct addition to the setpoint,
HR and LR are used to scale the trim input against SETP1 HR_SP and LR_SP.
LR This sets the low range: LR_in maps to LR. It would not be unusual for LR to be the same value as
HR but negative to give a symmetrical trim.
Filter A first-order filter with the time constant set applied to the input.
Invert TRUE maps HR_in to LR and LR_in to HR. TRUE also inverts the effect of the trim signal.
SETP3 This block is used to enter the ratio setpoint and calculate the measured ratio for display.
HR_SP The high range of the ratio setpoint. HR_SP and LR_SP should be chosen to give a clear display on
the PV and SP bargraphs of loop 3 which take their ranges from these parameters.
LR_SP The low range of the ratio setpoint.
HL_SP This sets a high limit for the setpoint including any trim.
LL_SP This sets a low limit for the setpoint including any trim.
Alarms These are the process alarms of the control loop. Note: Priority 0 disables the alarm completely.
Priority 6-15 need to be acknowledged. Priority 11-15 open the Alarm relay. Alarms of priority
equal to USR_ALM.Priority will open the Watchdog relay.
HighAbs The measured ratio exceeds HAA
LowAbs The measured ratio is less than LAA
HighDev The measured ratio exceeds the set ratio by HDA
LowDev The measured ratio is less than the set ratio by LDA
Table 5-9 Loop 3 parameters — strategy #4 (ratio station)

Setup sheets Fixed-function strategies
SETUP SHEETS — ALL STRATEGIES

Tables 5-10 to 5-13 list all four strategies’ configurable fields and their default values, to-
gether with a very brief description of their function. The loops apply to all the strategies,
except wher indicated. You may want to photocopy these pages and record your custom-
ised parameter values on them.
Loop 1
SL661 Instr_No 1 BiSynch address
SWS_1 W Field1 Bit0 FALSE Power up mode
Bit4 FALSE tru - On/Off control
BitD FALSE Tag PIC-001
RSP_1 Filter 0.00 Input filter
Sqrt FALSE Input conditioning
DIN_1 Invert Bit0 FALSE tru inverts COMP EN(0)
Bit1 tru FALSE inverts REM SP EN(1)
Bit2 FALSE tru inverts TRACK EN(1)
Bit3 FALSE tru inverts HOLD EN(1)
PV__1 Filter 1.00 Input filter
continued…
Fixed-function strategies Setup sheets
…continued
TRIM1 MODE MANUAL Operating mode (AUTO or MANUAL)
PV 0.00 Trim setting if MANUAL
HR 100.00 Engineering units high
LR 0.00 Engineering units low
Filter 0.00 Input filter
SETP1 HR_SP 100.00 Engineering unitshigh for SP and PV
HL_SL 100.00 High limit on SL
HAA 100.00 High absolute alarm on PV
LAA 0.00 Low absolute alarm on PV
HDA 100.00 High deviation alarm on PV
LDA 100.00 Low deviation alarm on PV
Dis_DP 2 Decimal point position
DOP_1 Invert Bit0 tru FALSE inverts HI ALM OUT(0)
Bit1 tru FALSE inverts LO ALM OUT(0)
Bit2 FALSE tru inverts REM AUT AUT(0)
Bit3 FALSE tru inverts HOLD+MAN OUT(0)
PVOP1 HR_out 10.00 Output voltage high
LR_out 0.00 Output voltage low
3TRM1 TimeBase Secs Control settings time base (TI & TD)
XP 100.00 Proportional band
TI 10.00 Integral time
TD 0.00 Derivative time
Deadband 0.00 Hysteresis for On/Off control
TRK1 MODE AUTO Operating mode (AUTO or MANUAL)
PV 0.00 Track setting if MANUAL
LR-in 0.00 Input voltage low
MANS1 HL_OP 100.00 High limit on control output
LL_OP 0.00 Low limit on control output
OP__1 HR_out 10.00 Output voltage high
Table 5-10 Setup sheet for Loop 1 — all strategies

Loop 2
SL662 Instr_No 1 BiSynch address
SWS_2 W Field1 Bit0 FALSE Power up mode
Bit4 FALSE tru - On/Off control
BitD FALSE Tag PIC-001
RSP_2 Filter 0.00 Input filter
DIN_2 Invert Bit0 FALSE (Unused)
Bit1 tru FALSE inverts REM SP EN(1)
Bit2 FALSE tru inverts TRACK EN(1)
Bit3 FALSE tru inverts HOLD EN(1)
PV__2 Filter 1.00 Input filter
HR 100.00 Engineering units high
LR 0.00 Engineering units low
continued…

Fixed-function strategies Setup sheets
…continued
SETP2 HR_SP 100.00 Engineering unitshigh for SP and PV
HAA 100.00 High absolute alarm on PV
DOP_2 Invert Bit0 tru FALSE inverts HI ALM OUT(0)
Bit1 tru FALSE inverts LO ALM OUT(0)
Bit2 FALSE tru inverts REM AUT AUT(0)
Bit3 FALSE tru inverts HOLD+MAN OUT(0)
PVOP2 HR_out 10.00 Output voltage high
3TRM2 TimeBase Secs Control settings time base (TI & TD)
XP 100.00 Proportional band
TI 10.00 Integral time
TD 0.00 Derivative time
Deadband 0.00 Hysteresis for On/Off control
TRK2 MODE AUTO Operating mode (AUTO or MANUAL)
PV 0.00 Track setting if MANUAL
LR-in 0.00 Input voltage low
MANS2 HL_OP 100.00 High limit on control output
LL_OP 0.00 Low limit on control output
OP__2 HR_out 10.00 Output voltage high
Table 5-11 Setup sheet for Loop 2

Loop 3
SL663 Instr_No 1 BiSync address
DCpl3 Filter 0.00 Ratio Decoupling Filter
HR 100.00 Ratio trim high
LR 0.00 Ratio trim low
SETP3 HR_SP 100.00 Ratio high range for SP and PV
LR_SP 0.00 Ratio low range for SP and PV
HAA 100.00 High absolute alarm on PV (measured ratio)
Table 5-12 Setup sheet for Loop 3 — strategy #4 (ratio)
Loop 4
USR_ALM Priority 2 Watch dog relay alarm setting (0-15)
T60_** Options NoKeyPrt tru FALSE - key required

NoKeyFul FALSE FALSE - key required
BinSpd1 FALSE Bisynch baud rate.
BinSpd2 FALSE Default gives 9600 baud
Table 5-13 Setup sheet for Loop 4 — all strategies

Fixed-function strategies Communications
COMMUNICATING WITH THE T640

There are three ways in which the T640 may be integrated into a system — via the ALIN,
via TCS binary Bisync protocol, and via MODBUS/JBUS. (Please refer to Chapter 2 un-
der Hardware Configuration for communications configuration information.)
Communicating on the ALIN

This is always available and gives tight integration into the Eurotherm Process Automa-
tion LIN system. Blocks have been included in the fixed function strategies specifically
for caching. The most important of these are PID_CONN blocks, which allow interaction
with the control loops. The names of the PID_CONN blocks are:
PIDC1** for Loop 1, PIDC2** for Loop 2, and PIDC3** for Loop 3,
where ** is the instrument node number. For example, if the ALIN address of the instru-
ment were 88, Loop 1’s control block would be named PIDC188. T640 automatically
substitutes the node number for **.
Furthermore, eleven diagnostic blocks are provided for the instrument as a whole. For de-
tails on the operation of these blocks, please refer to the LIN Blocks Reference Manual
(Part No. HA 082 375 U003). Table 5-14 lists these block types and their names.
Block type Block name
DB_DIAG DDIAG_**
EDB_DIAG EDIAG_**
LIN_DEXT LDEXT_**
ALINDIAG ALIND_**
XEC_DIAG XDIAG_**
T600TUNE T600T_**
EDB_TBL ETBL_**
ROUTETBL ROUTE_**
RTB_DIAG RDIAG_**
ISB_DIAG IDIAG_**
ISB_DEXT IDEXT_**
Table 5-14 Diagnostic blocks in the T640 fixed function strategies
TCS binary Bisync protocol

As an option, the T640 can be fitted with RS422/RS485 communications. Each loop will
emulate a 6366 as far as communications is concerned. This allows the T640 to be inte-
grated into existing 6000 instrument-based systems. Setting up the RS422 node address is
done within the SL661, SL662 and SL663 blocks.
MODBUS/JBUS
This too requires the RS422/RS485 option. To set up and download the MODBUS tables
to the T640, you need T500 LINtools. A full explanation of the configuration of the
MODBUS interface is given in the T500 User Guide (Part No. HA 082 377 U005).

Log changes file
Chapter 6 CHANGES LOGFILE
LOGFILES
The T640 maintains in EEPROM a logfile of every parameter change made via the front
panel database access mechanism, i.e. via the INS button. (Please refer to Chapter 4, User
interface, for full details on database access and use of this button.) The logfile contains a
complete record of what was changed, when it was changed, and by whom.
Logfile organisation
The logfile adopts the same root filename as the .DBF file from which the database was
loaded, but with extension .Lnn, where nn is the logfile number, ranging from 01 to 99.
When a logfile becomes full (i.e. has reached 1Kbyte) it closes and its number is written to
the T600 block’s Log_File parameter. The previously held file is deleted. When more
logfile data is generated a new file with incremented logfile number is automatically cre-
ated. Thus the T600 block logfile number defines a file that may be safely uploaded. If
Log_File is ‘0’, there is no file to upload. Only the two most recent logfiles are retained in
memory: the currently open file and the last closed one.
A logfile can be closed before it is full if another type of file (e.g. a strategy file) is added
to EEPROM to make the logfile no longer the latest file. This is because T640’s filing
system allows data to be appended only to the last file in EEPROM.
Logfile records
There are two possible records in a log file:
■ Inspect Mode entry. This record shows the date of entry into Database Inspect
mode, and which security key was used to access the mode. One of these records is
written to file only if parameter changes were actually made.
Each record is a single text line of the format
dd/mm/yy T:aakkkk
where: dd/mm/yy = the date in day/month/year representation
T = type of security key (P = partial, F = full, G = global,
ignoring area no.)
aa = area number (0 - 63)
kkkk = security key number (0 - 4095).

Log changes file
■ Parameter Change entry. This record shows a single instance of parameter

updating. In order to control file size when the operator is ‘nudging’ to the value,
there must be a significant time gap between nudges to result in more than one record.
Where a change in direction occurs the peaks in each direction are logged (as a mini-
mum). The time logged is the time that the final value was written.
Each record is a single text line of the format
hh:mm:ss block.field.subfield = value
or, for a change of mode,
hh:mm:ss LOOP n = X
where: hh:mm:ss = the time in hours/minutes/seconds (24hr) representa-
tion
block … = the full path of the point being modified
value = the new value
n = the loop number
X = the new mode, i.e. M, A, or R.
Example logfile record

21/01/93 F: 3:2345
01:12:15 T640C6C3.Options.FPdisl = TRUE
01:12:18 T640C6C3.Options.NoKeyFul = FALSE
01:12:25 LOOP 4 = M

Inside T640
Chapter 7 INSIDE T640
INTERNAL LAYOUT
Please refer to Chapter 2, Installation & startup, for details of T640’s dimensions, internal
physical and electrical layout, and hardware configuration. The present chapter deals with
the software and hardware blocks functioning within the T640.
FUNCTIONAL BLOCKS
Figure 7-1 shows a functional block schematic of the T640. The main functional blocks
are: the motherboard, the front panel, the I/O sub-assemblies (up to two), and the rear-
panel customer screw terminals.
FRONT PANEL 2-off 12-way MOTHERBOARD

connectors (P4-5)
Display CPU health line

processor ISB Relay 2 Alarm O/P
Outputs 2 Watchdog O/P
+3.8V
+5V
IR
Detector +5V 4 AC mains
Power
RAM Main CPU +12V OR
Supply 4 Dual DC
Displays status
32-way status
Comms 3 ALIN (isolated)
DIN
connector Interface 5 RS422/485 (isol.)
(P1) [option]
12-way
I/O
EPROM connector 22-way terminal
EEPROM (P3) block
Pushbuttons Memory DIL Switchbanks
module ISB +18V, +5V
To I/O board(s)
Figure 7-1 T640 Functional block schematic
Motherboard
The motherboard is the main electronics board in the instrument to which all other sub-
assemblies connect. It carries the main CPU, communications electronics, power supply,
and the two configuration DIL switchbanks.
Main CPU
The main CPU has its own limited I/O to read the configuration DIL switches and the
power supply status. It also provides a watchdog output to indicate the health of the proc-
essor, and a common alarm output. Both these outputs are available at the rear connectors.

Inside T640
Details on the operation of the watchdog and alarm outputs are given in Chapter 8, Error
conditions & diagnostics.
Memory
Memory consists of EPROM for T640 firmware, EEPROM for databases, standard strate-
gies and logfiles, and static RAM for the working memory and operational data (running
database with setpoints etc.). The RAM is maintained by a Supercap. This obviates the
need for a battery in the instrument, and means that the T640 resumes its exact control
conditions in the event of a power failure of up to 24 hours. Key operating parameters,
controller modes, setpoints, etc., are passed to EEPROM on power-down to ensure that the
controller returns to its correct operating conditions if the power fails for more than 24
hours. (Refer to Chapter 2 for details of T640’s power-up routines.)
The EEPROM (and EPROM) memory resides in a removable memory module. This al-
lows a new strategy to be plugged directly into an existing controller, or conversely allows
a strategy to remain if the controller must be changed. (Chapter 2 describes memory-mod-
ule and T640 unit replacement.)
Table 2-4 in Chapter 2 summarised the major T640 file types. Further details on these
files are given in the relevant sections of this manual.
Comms ports
There are three communications ports — two serial, and one peer-to-peer. The two serial
ports are the internal serial bus, and the Bisync/MODBUS port, available as options at the
rear panel via an isolated RS422/485 driver on the motherboard. Jumpers and mother-
board switches select which port is connected via the driver. (Chapter 2 specifies these
jumper and switch configurations.) The third port is the peer-to-peer ALIN channel.
Internal Serial Bus (ISB). The ISB communicates between the main CPU, the
I/O card(s), and the front panel. It also supports remote I/O and external faceplates from
the rear connections (not available at this release). The external link is half duplex, using
a 5-wire RS485-derivative physical and electrical interface to the I/O cards. The front
panel and any internally fitted I/O cards are directly coupled to the main processor at logic
levels.
The ISB is asynchronous, with 1 start bit, 8 data bits, 1 control bit, and 1 stop bit, operat-
ing at 78.125kbits/second. This speed allows messages to be transferred with negligible
delay.
The main processor acts as master on this communications bus; no other nodes can trans-
mit without being invited to. Each slave node on the bus is given a node number, in the
range 0 - 15. Node number 15 is reserved for the front panel, and node numbers 0 - 7 are
allocated to I/O cards. Each I/O card has switches for setting up its ISB node number.
Bisync/MODBUS Port. This port provides a Bisync slave interface for connection
to existing supervisors or to industry-standard MODBUS units (selectable via SW1/1), via
the RS422/485 driver .

Inside T640
LIN PC-based
Bridge to LIN Configurator
(T221) (LINtools)
ALIN Peer-to-Peer Comms
Main CPU
Internal Serial Bus
I/O I/O Front

Panel
T640 UNIT
Figure 7-2 ALIN communications schematic
ALIN peer-to-peer comms. A high-speed (2.5Mbaud) short-distance form of the

LIN, the ALIN is the main communications channel in the instrument, used for configura-
tion, supervision, and inter-instrument communication. See Figure 7-2. It supports all
current LIN features — block attachments, field writes, file transfers, etc. — except chan-
nel redundancy. ALIN and LIN can be interconnected via a T221 bridge.
ALIN is provided by an ARCNET physical layer and uses the same, though enhanced, ap-
plication layer as the LIN. The peer-to-peer enhancements — synchronised realtime clock
and time-stamped alarms — are provided by the T221 bridge.
Power supplies
T640 has two power supply options — DC input, and AC input. See Chapter 9, Specifica-
tions, for details.
DIL switchbanks
Switchbanks 1 and 2 set T640’s comms function and address, startup procedure, standard
strategy selection, and also enable/disable a loop failure watchdog alarm. (Refer to Chap-
ter 2 for switchbank functions.) Chapter 5 details the pre-configured fixed-function strate-
gies stored in the T640.
Front panel
The front panel display sub-assembly is an intelligent unit controlled by its own micro-
processor. It communicates with the main CPU on the motherboard via the internal serial
bus (see Figure 7-1). The display features are specified in Chapter 9. Using the front
panel and the security key are described in Chapter 4, User interface.

Inside T640
I/O sub-assemblies
The T640 can be supplied with several I/O options, in the form of I/O boards that mount
on the motherboard and communicate with it via the ISB. Note that a T640’s I/O is not
restricted to its own direct inputs, as it can access data from other instruments across the
ALIN. For full descriptions and specifications of the available I/O, see Chapter 9, Specifi-
cations. Chapter 2 (Hardware configuration section) shows an example of how I/O
boards fit inside the T640
Customer screw terminals

Full details of the rear-panel screw terminals are given in Chapter 2 in the Connections &
wiring section.

Error conditions & diagnostics
Chapter 8
ERROR CONDITIONS & DIAGNOSTICS
This chapter deals with T640’s error conditions, diagnostic messages, safety features, and
alarm strategy. Power-up messages tell you what T640 is doing or attempting to do when
power is restored, and subsequently database alarms and hardware/software faults are sig-
nalled as special front-panel messages, or 4-digit hex codes which can be looked up in Ta-
ble 8-1.
The aims of T640’s safety features are to report abnormal and fault conditions to the out-
side world, to prevent — as far as is practicable — unsafe conditions occurring, and if
they do occur, to restore the system to a safe state as quickly as possible.
POWER-UP DISPLAYS
Normal power-up
Power-on Reset. normally flashes briefly in the red tag display when T640 is powered up,
while the front panel awaits communications from the main CPU. Then, WarmStrt Try-
ing, TepidSrt Trying, or ColdStrt Trying, flash to tell you the type of startup procedure
T640 is attempting. If a standard strategy is being loaded for the very first time, Un Pack
Database flashes in the tag display as the file is being decompressed. Finally, the fascia
adopts the normal display (as described in Chapter 4).
ERROR CONDITIONS
■ CPU FAIL flashes in the 5-digit display if the CPU fails to establish comms to the
fascia. This message can also mean a watchdog failure (see later under CPU watch-
dog, incorrect motherboard comms option SW1/2 setting (see Table 2-3 in Chapter 2,
Hardware configuration section), or an absent/faulty memory module.
■ HALTED in the tag display, with Error flashing in the 5-digit display, means the user
task in the main display has halted.
■ Err hhhh flashing brightly in alternation with the normal tag display means a filing
system or database system error (e.g. coldstart file access failure) identified by a 4-
digit hex code hhhh. Filing system alarms override database alarms on the front panel.
To clear them, press the ▲ and ▼ keys simultaneously. Table 8-1 lists all the hex code
error numbers and their meanings.

■ Database alarms. Unacknowledged alarms in the loop occupying the main dis-
play cause the tag display to bright flash the highest priority alarm name in alternation
with the standard message. Unacknowledged alarms elsewhere display LP n ALM,
where n is the relevant loop number. Please refer to Chapter 4, Alarm display & in-
spection section, for further details on alarm display, inspection, and acknowledge-
ment.
Error Meaning
6001 Failure to load MODBUS database
6002 Failure to start MODBUS database
8201 Device not mounted/compatible (not formatted, or corrupt)

8202 Invalid device specified
8203 Error performing I/O to device (write/read protected by wrong switch settings)
8204 Feature not implemented
8205 Formatting error
8206 Physical device not present
8207 Device full
8208 File not found
8209 No handles for file (not enough memory to open file and note its state)
820A Bad filename
820B Verify error
820C File locked, already in use
8301 Bad template

8302 Bad block number
8303 No free blocks
8304 No free database memory
8305 Not allowed by block create
8306 In use
8307 Database already exists
8308 No spare databases
8309 Not enough memory
8320 Bad library file (corrupt ROM file)
8321 Invalid template in library
8322 Bad server (corrupt file when loading)
8323 Cannot create EDB entry
8324 Bad file version
8325 Bad template spec
8326 Unable to make block remote
8327 Invalid parent
8328 Corrupt data in .DBF file
8329 Corrupt block spec
832A Corrupt block data
832B Corrupt pool data
832C No free resources
832D Template not found
832E Template resource fault
8330 Cannot start
8331 Cannot stop
8332 Empty database
continued …

… continued
Error Meaning
8333 Configurator in use
8340 .DBF file write failed
8341 More than one .RUN file found
8342 .RUN file not found
834A Connection source is not an output
834B Multiple connection to same input
834C Connection destination not input
834D No free connection resources
834E Bad connection source/destination block/field
834F Invalid connection destination
8350 Warmstart switch is disabled
8351 No database was running
8352 Real-time clock is not running
8353 Root block clock is not running
8354 Coldstart time was exceeded
8355 Root block is invalid
8356 More than two PID or 3_TERM blocks in a 2-loop controller
8357 Coldstart switch is disabled
8360 Unsynchronised Block Types
8361 DB/Filing system mismatch
8362 Unsynchronised Secondary
8363 Operation forbidden whilst CPUs synchronising
8364 Power-up data inhibits run
8365 POST hardware failure
8366 Not fixed-function strategy
8367 Default strategy missing
FFFF (Unspecified error)

Table 8-1 T640 Error numbers & their meanings
ALARM STRATEGY
Alarm priorities
Alarm priorities in the T640 follow the convention established in all LIN-based instru-
ments. They can be set in individual blocks via their Alarms fields and are defined as:
■ 0 (lowest priority) = alarm disabled.

■ 1 -5 = annunciated with auto acknowledge. These alarms are annunciated only while
the alarm condition persists, and clear themselves when the alarm condition clears,
without needing manual acknowledgement.
■ 6-10 = annunciated with manual acknowledge. These alarms do not automatically
clear when the alarm condition disappears, but remain active until manually acknowl-
edged.

■ 11-15 (top priority) = annunciated with manual acknowledge and alarm relay. These
alarms work in the same way as priority 6-10 alarms but in addition they trip the T640
hardware alarm relay (see below) and set the T600 block’s Status/Alarm bit.
Alarm annunciation
Annunciated alarms are indicated on the controller front panel by means of the red LED in
the ALM button, and also via the tag display. Please refer to Chapter 4 for further details.
Alarm events
As an alarm state changes, into or out of alarm, (occurring at block execution time) this
event is advised to an alarm event system where it is date/time stamped (not implemented
at Issue 1). A supervisor may attach to the alarm events of an instrument (not at Issue 1).
Once so attached, the instrument checks at regular intervals to see if any new alarm events
have occurred and transmits them to the supervisor.
To ensure consistent date/time stamping, the date/time is regularly copied across the peer-
to-peer communications link, via the T221 bridge (not implemented at Issue 1).
Alarm relay
The alarm relay’s contacts are closed when energised and in the no-alarm condition.
When a priority 11-15 alarm occurs in the T640, or if the database halts, the contacts open.
They also open if the relay is de-energised, i.e. fail safe operation.
CPU WATCHDOG
Watchdog output
The instrument is provided with a watchdog output on the main processor unit, which
flags an alarm condition if the processor fails. If the watchdog trips, the processor is reset
and restarted.
Watchdog relay
A relay output is provided to indicate that the watchdog has tripped. The contacts are
closed when energised and in the healthy condition, but open if the CPU fails. Addition-
ally, the front panel 5-digit display flashes CPU FAIL until the processor has been re-
started.

Loop fail
The CPU can also force the watchdog into alarm, to flag if a loop (user task) fails to run,
or if the database halts. This facility may be enabled/disabled via the motherboard DIL
switchbank SW1, switch 5 (see Figure 2-12 in Chapter 2, Hardware configuration sec-
tion). If a loop fails to run, the outputs assume the state defined in the OPTIONS/
CPUFlLo field of the output block (e.g. ‘low’).
User alarm
The watchdog relay can also act as a general-purpose user alarm, via the T600 block’s
UsrAlm field. A TRUE input to UsrAlm from the control strategy opens the relay con-
tacts. A FALSE input closes them, but is overridden by a watchdog alarm.
Main processor (CPU) fail

Both I/O cards and the front panel microprocessor can detect failure of the main CPU, by
virtue of there being no activity on the internal serial bus. In this case the front panel re-
places the normal 5-digit PV display with a flashing CPU FAIL message. The I/O cards
can be programmed with action to be performed on main processor fail, e.g. outputs hold
or outputs low. If the database stops, either due to a fault, or as a result of a command
over the LIN, this will also cause the I/O cards to adopt their CPU-fail state.
Forced manual mode

In user tasks with MODE blocks, the block adopts forced manual mode under error condi-
tions (i.e. sumcheck, open circuit PV, or other strategy-defined conditions).

Specifications Base unit
Chapter 9 SPECIFICATIONS
T640 BASE UNIT
Panel cut-out & dimensions

Please refer to Chapter 2, under Installation, for details.
Mechanical
Fascia dimensions: height 144mm, width 72mm.
Mounting panel aperture: height 138 +1 –0 mm, width 68 +0.7 –0 mm.
Behind mounting panel: depth 258mm (measured from panel front).
Front of mounting panel: depth 10.6mm.
Weight: 2.15kg.
Environmental
Storage temperature: –10°C to +85°C, at humidity of 5-95% (non-condensing).
Operating temperature: 0°C to +50°C. The enclosure must provide adequate
ventilation, and heating if required to avoid condensation
at low temperatures.
Atmosphere: Unsuitable for use above 2000m or in explosive
or corrosive atmospheres.
Front panel sealing: to meet EN60529: IP65.
EMC emissions: to meet EN50081-2 (Group 1; Class A).
EMC immunity: to meet EN50082-2.
Electrical safety: to meet EN61010, Installation category II.
Voltage transients on any mains power connected to the
unit must not exceed 2.5kV.
Electrically conductive pollution must be excluded from
the cabinet in which the unit is mounted.
Isolation: All isolated inputs and outputs are double-insulated as
specified in EN61010 to provide protection against electric
shock. (Isolation levels for particular I/O types are stated
in the relevant section of the specification for the I/O board
concerned.)
Vibration: to meet BS2011 Part 2.1, Test Fc, Table CII, ‘Equipment
intended for large power plant and general industrial use’
(2g, 10-55 Hz).
Shock: to meet BS2011 Part2.1, Test Ea, Table II, ‘General test for
robustness, handling and transport’ (15g, 11ms).
Base unit Specifications
Front panel displays

PV bargraph: red 51-segment vertical % display (flashable via block).
SP bargraph: green 51-segment vertical % display (flashable via block).
Output bargraph: yellow 10-segment horizontal display
(segments individually addressable).
Numeric display: 5-digit, red 7-segment.
‘PV-X’ legend: lit red when PV indicated in Numeric display.
Tag display: 8-character, red dot-matrix (user-configurable).
Units display: 5-character, green dot-matrix (eng. units or SP).
‘SP-W’ legend: lit green when SP indicated in Units display.
Loop status summary

deviation/PV bargraph: 4-off red 7-segment vertical displays, settable via block to
1/2/3%, 1/5/10%, or 10/20/30% deviation; or to 100% PV.
Central bicolour LED glows green when deviation shown.
loop mode: A(uto), R(emote/ratio) green lit single letters
M(anual), H(old), T(rack) orange lit single letters.
loop selected: green lit arrow symbol under deviation/PV bargraph.
Pushbuttons
loop control: 6-off membrane pushbuttons with symbols—

R
R (with green LED)
A
A (with green LED)
M
M (with orange LED)
SP-W
SP
‘raise’ ▲
‘lower’ ▼
INS
parameter access: INS pushbutton ??
ALM
alarm acknowledge: ALM pushbutton (with red LED)
Specifications Base unit
Table 9-1 Dot-matrix display character set (representation)
ALIN Specifications
Dot-matrix display character set

Table 9-1 shows (in representative typefaces) the complete set of characters displayable by
the two dot-matrix front-panel displays — the Tag display and the Units display. The
number under each character is its decimal code, used to specify that character for display
via the LINtools configuration package. Codes 0 to 31 are reserved and are not user-ac-
cessible.
Please refer to the T500 LINtools User Guide (Part No. HA 082 377 U005) for further details.
Relays
Alarm relay: SPST. 24V ac/dc at 1A. Absolute maximum rating 30Vrms, 60Vdc.
Watchdog relay: SPST. 24V ac/dc at 1A. Absolute maximum rating 30Vrms, 60Vdc.
Power supplies
Mains version
Input voltage range: 90 - 265 Vac rms.
Input frequency range: 45 - 65 Hz.
Maximum peak input current: 1.1A.
Power rating: 25VA.
Holdup time: 20ms.
Fuse: T-type (IEC 127 time-lag type)
20 ¥ 5 mm 250Vac antisurge cartridge, 500mA.
DC version
Number of inputs: 2 — Channel 1 (main input), channel 2 (backup).
Input voltage range: 19 - 55 V (including rectified 48Vac).
Power rating: 25VA.
Holdup time: 20ms.
Fuse: T-type (IEC 127 time-lag type)
20 × 5 mm 250Vac antisurge cartridge, 2A.
T950 Security key

Battery: 12V alkaline manganese dioxide type, of overall length
27.5-28.5 mm, diameter 9.62-10.62 mm.
E.g. Duracell™ MN21, Panasonic™ RV08, or equivalent.
(Refer to Ch2 for safety precautions.)
ALIN
The ALIN runs on screened twisted pair. Phase A, pin 21, should be bussed to other Phase
A signals and likewise Phase B, pin 22. The cable screen should be connected to ALIN
Gnd, pin 20. The ALIN connections are galvanically isolated within the T640 to assist
with noise rejection and simplify system wiring. The key specifications of the ALIN are
summarised as follows:
Specifications
Cable type: screened twisted pair.

Line impedance: 82 , nominal.
Network topology: single non-branching network.
Network terminations: 82 at each end.
Maximum load: 20 nodes.
Maximum length: 100 metres.
Grounding: single point ground per system.
RS422 COMMUNICATIONS
Selection: Via motherboard DIL SW1 & jumper links (see Chapter 2).
Protocols supported: MODBUS and BISYNC.
Transmission standard: 5-wire RS422 (0-5V).
Line impedance: 120 - 240 twisted pair .
Line length: 1220m (4000ft) maximum at 9600 baud.
Units per line: 16 instruments electrical maximum, expandable to 128
electrical maximum by nesting of 8245 Comms Buffers.
RS485 COMMUNICATIONS
Protocols supported: MODBUS.
Transmission standard: 3-wire RS485 (0-5V).
Line impedance: 120 - 240 twisted pair .
Line length: 1220m (4000ft) maximum at 9600 baud.
Units per line: 16 instruments electrical maximum.
BISYNC PROTOCOL
Conforms to: ANSI-X3.28 - 2.5 - A4 Revision 1976 — binary version.
Medium: RS422.
Implementation: Via appropriate T6000 category function block running in
the T640 (see the LIN Blocks Reference Manual).
Addresses: 128 maximum, software-selectable via the S6000 function
block’s Instr_No parameter.
Data rate: Software-selectable, via T600 function block’s BinSpd1 &
BinSpd2 parameters, from 300, 1200, 4800, & 9600 baud.
Character length: 11 bits made up of —
1 start + 8 data + 1 parity (even) + 1 stop.
Software Specifications
MODBUS PROTOCOL
Transmission mode: MODBUS RTU (8-bit) supported.
Medium: RS422 or RS485.
Implementation: Via ‘gateway’ file (.GWF) configured via T500 LINtools
MODBUS configurator and stored in the T640 together
with the database file (.DBF).
Slave addresses: 254 maximum, software-selectable via T500 LINtools
MODBUS configurator.
Data rate: Software-selectable (via LINtools) from 110, 150, 300,
600, 1200, 2400, 4800, and 9600 baud.
Parity & stop bits: Software-selectable (via LINtools) from none, odd, and
even parity, with 1 or 2 stop bits.
SOFTWARE
Maximum resources supported

The table shows the default maximum resources supported by the T640. (This informa-
tion is also available in the local DB_DIAG blocks.)
Resource Default Maximum

Blocks 256
Templates 50
Libraries 32
EDBs 8
Featts 128
Teatts 10
Servers 5
Connections 512
Note that if a database is loaded having more resources than the default maximum, the
maximum is set to the new value — which may mean there is not enough memory to load
the whole database. In this case it is the connections that disappear first. Featts are an ex-
ception. When a database is saved there are generally no Featts present because they are
created dynamically at runtime, preventing the default maximum from being overridden.
Specifications
Maximum sequencing resources supported
Resource Maximum
Simultaneous independent sequences 10
SFC actions 50
Steps 150
Action associations 600
Actions 300
Transitions 225
Servers 5
Sequence execution rate (determined by repeat rate of User Task 4 loop)
Specifications
[This page intentionally blank]
Specifications High-level I/O
HIGH-LEVEL I/O
Layout
The high-level I/O electronics resides on a main I/O board mounted next to the mother-
board, which plugs into the central rear-panel 24-way terminal block (I/O site 1). These
terminals can carry only half the available I/O; the second half can be accessed at the left-
hand rear-panel 24-way terminal block (I/O site 2) via an expansion I/O board, fitted next
to the main board. (Figure 2-10 in the Hardware configuration section of Chapter 2 shows
this layout.)
T640 rear-panel customer connections

Please refer to Chapter 2, under Connections & wiring (Customer terminals), for details.
Input ranges
The appropriate 0-5 V or 0-10 V range is automatically selected by the software when you
configure the analogue input or output block in the control database. However, you can
override the software and select the 0-1.25 V range specifically by connecting together the
two pins of Jumper 1, and those of Jumper 2, on the main high-level I/O board. These are
located as shown in Figure 9-1. Both analogue inputs and voltage analogue outputs are
forced to the 1.25V range by these jumper links.
Burden resistors. If internal burden resistors have been specified (HIB and HGB
options), or if external burden resistors are fitted to the customer screw terminals, the ana-
logue input block’s range parameters — LR_in and HR_in — must be appropriately con-
figured to suit the plant’s current input range. Consult Table 9-2.
Jumper 1 Jumper 2
Figure 9-1 High-level I/O board showing 0 - 1.25V range jumpers
High-level I/O Specifications
Burden Plant AN_IP block setup:

Option resistor input LR_in HR_in
HIB 250 0 - 20 mA 0V 5V
4 - 20 mA 1V 5V
HGB 62 0 - 20 mA 0V 1.24V
4 - 20 mA 0.248V 1.24V
External 250 0 - 20 mA 0V 5V
4 - 20 mA 1V 5V
50 0 - 20 mA 0V 1V
4 - 20 mA 0.2V 1V
Table 9-2 Range settings for burden resistors
Calibration. The 1.25V range is supplied with a nominal calibration accuracy of bet-
ter than 5%. If required, the board may be recalibrated to an accuracy of 0.05% — please
refer to Eurotherm Process Automation for details.
NOTE. In the T640 HI and HIB options the 1.25V range is uncalibrated at the
present issue of hardware. This state is not flagged by the STATUS/BadCal bit.
LIN blocks parameters not supported

The LIN Blocks Reference Manual (Part No. HA 082 375 U003) describes in generic
terms every block and parameter that can be run in a T640 instrument. However, certain
parameters are not supported, or are only partially supported, by the high-level I/O board.
Table 9-3 lists these board-specific parameters.
Block type Parameter Support

AN_IP InType V option only
CJ_temp Not supported
LeadRes Not supported
STATUS PSUshort Not supported
BrkWarn Not supported
BrkDtctd Not supported when burden resistors in use
AN_OUT STATUS FaultCct Voltage outputs: short circuit only
Current outputs: not supported
OverDrv Not supported
Killed Not supported
ALARMS CctFault Voltage outputs: short circuit only
Current outputs: not supported
OvrDrive Not supported
DG_IN Thresh Not supported
InType Volts option only
DG_OUT Pullup Not supported
DGPULS_4 [1] Pullup Not supported
[1] With high-level boards in both T640 sites, only site 1 can support a DGPULS_4 block.
Table 9-3 High-level I/O board LIN blocks parameter support
Hardware organisation
Figures 9-2 to 9-4 are block schematics outlining the organisation of the high-level I/O
board hardware. Figure 9-2 shows the non-isolated analogue I/O, Figure 9-3 shows the
digital I/O, and Figure 9-4 shows the current outputs and transmitter power supplies.
Analogue inputs
Channels: 8.
Input range: 0-5 V and 0-10 V, with software-selectable range.
0-1.25 V range jumper-selectable (see Input ranges above).
Absolute max. input: 15V.
Resolution: 0.025%.
Accuracy: 0.05% of range.
ANALOGUE INPUTS
Site 2 Chn 4
Site 2 Chn 3
Site 2 Chn 2
Site 2 Chn 1 Input select
Site 1 Chn 4
Site 1 Chn 3 Mux
Site 1 Chn 2
Site 1 Chn 1
A to D
1E 10K
– Break ISB
* 1M detect
Threshold
+
An. gnd. –1.2V
*HIB, HGB options

nG EEPROM I/O MICRO-
nK Analogue
nN calibration data CONTROLLER
Analogue ground
Output select
Mux
Site 2 Chn 2
Site 2 Chn 1
Site 1 Chn 2 – Output
overload
Site 1 Chn 1
+
1L
Mux
Sample & hold D to A
Analogue ground
ANALOGUE OUTPUTS
Figure 9-2 Analogue input & output block schematic
DIGITAL INPUTS
Site 2 Bit 3 Parallel In Serial Out
Site 2 Bit 2
Site 2 Bit 1
Site 2 Bit 0
Site 1 Bit 3
Site 1 Bit 2
Site 1 Bit 1
INPUT
Site 1 Bit 0 +5V Dig LATCH
1P Latching pulses
100K
20ms
100K
Digital ground
I/O MICRO-
nY CONTROLLER
nZ
Digital ground (common to I/O) Serial data IN

2K7 Serial data OUT
24V (nom.)
ext. input Clock
15V digital
or 1X
(internal)
15V (nom.)
output
Digital supply
Site 2 Bit 3
Site 2 Bit 2
Site 2 Bit 1
Site 2 Bit 0
Site 1 Bit 3
Site 1 Bit 2
Site 1 Bit 1
Site 1 Bit 0
OUTPUT
LATCH
2K2
1T 68R
Serial In Parallel Out

Digital ground
DIGITAL OUTPUTS
Figure 9-3 Digital input & output block schematic
Gain drift: 30ppm/°C.

Offset drift: 65µV/°C.
Input impedance: 1 M pull-down to –1.2V .
Break detection: within 1 sample. Protection strategy selected from within
the configuration (up-scale, down-scale, etc.).
Isolation: none.
Sample rate: 9ms per configured input. Only the configured inputs are
scanned. The fastest loop update cannot be less than 20ms.
CURRENT OUTPUTS 60V

Isolation
1A
I+ +28V (isolated) +5V isolated
Pulse-width
1B
I- modulated
output
+ DC
recovery
220R 0V isolated
0V isolated
Isolated
power I/O MICRO-
supplies
CONTROLLER
60V I/O card
Isolation PSU
Isolated
power
supplies
CURRENT OUTPUTS
2A
I+ +28V (isolated) +5V isolated
Pulse-width
2B
I- modulated
output
+ DC
recovery
220R 0V isolated
0V isolated TRANSMITTER PSU

TX+ 22R
1C
+
∆ >0.6V
–
PSU OUTPUT
Vref
24V TX-
1D
TRANSMITTER PSU
TX+ 22R
0V 2C
25mA
+
∆ >0.6V
–
Vref
TX-
2D
Figure 9-4 Current output & transmitter PSU block schematic
Internal burden resistors

Values: HIB option — 250R.
HGB option — 62R.
Power: 0.25W.
Tolerance: 0.1%.
Temperature coefficient: 15ppm/°C.
NOTE. Tolerances and temperature coefficients must be added to the specified

analogue input tolerances.
Transmitter power supplies

Channels: 2.
Voltage: 24V ±5%.
Current: 0-22 mA.
Current limit: 30mA maximum.
Isolation: 60V ac or dc working.
Voltage analogue outputs

Channels: 4.
Output range: 0-5 V and 0-10 V, with software-selectable range
0-1.25 V range jumper-selectable (see Input ranges above).
Resolution: 12 bits.
(1.25 and 2.5 mV, for the 5 and 10 V ranges resp.)
Accuracy: 0.05% of range.
Offset drift: 70µV/°C.
Current drive: ±5 mA.
Overload detection: triggered if the output cannot maintain the desired voltage.
Isolation: none.
Current analogue outputs

Channels: 2.
Output range: 0-20 mA. (Rangeable 0-10 mA, 0-20 mA, 4-20 mA etc.)
Over-range: 22mA.
Resolution: 5µA.
Accuracy: 0.1%.
Offset drift: 0.9µA/°C.
Output drive: 0-1 k .
Isolation: 60V ac or dc working.
Digital inputs
Channels: 8.
Thresholds: logic 1: 7.5V minimum
logic 0: 2.5V maximum.
Hysteresis: 1.0V minimum, 3.5V maximum.
Input voltage: 28V maximum.
Input impedance: 200k for inputs <10V , 100k for inputs >10V .
Isolation: none.
Digital outputs
Channels: 8.
Output levels: logic 0: 0V
logic 1: 15V
(14.0V-15.5V internal supply, or external supply).
External supply: dual function:
as input: 15.5V minimum, 28V maximum.
as output: 14.0V minimum, 15.5V maximum, ( 7mA)
sourced via 2K7 resistor. (Allows hardware
pullup of up to 8 digital inputs.)
Drive impedance: logic 0: 68 , 25mA maximum sink current to maintain
logic 0 output level.
(37mA absolute maximum sink current.)
logic 1: 2.2k .
Isolation: none.
General
The environmental, physical, and electrical specifications for this assembly are the same
as for the base unit.
I/O calibration
Please contact Eurotherm Process Automation if you need to re-calibrate your I/O boards.
NOTE. In the standard (i.e. non fixed-function) version of the T640 you can re-
calibrate I/O boards by installing and running special AI_CALIB and AO_CALIB
function blocks in the database. Full details are given in the standard T640 Prod-
uct Manual (Part No. HA 082 468 U999)
I/O circuits
Figures 9-5 to 9-7 show schematically some ways to use the high-level I/O.
1T
Site 1 1U
Plant
digital logic
outputs 1V
inputs
1W
Pullup input (serves both sites)

1X + Customer’s
PSU
Digital 1Y – (15.5V - 28V)
ground 1Z
Plant logic 0V
2T
Site 2 2U
Plant
digital logic
outputs 2V
inputs
2W
Digital 2Y
ground 2Z
Plant logic 0V
Figure 9-5 Digital outputs driving plant logic using customer’s PSU
NOTE
Customer’s 24V
PSU Each digital input
can sink up to 25mA
– + max. at logic 0.
When output HIGH,
relay OFF.
1T
D RL
LED
Relay
Site 1
outputs
digital 1U
outputs to plant
CAUTION!
1X 24V pullup input (serves both sites) Digital outputs
power up LOW, so
Digital 1Y relays will be ON
ground 1Z till strategy starts
running (up to 3s).
2T
Relay
Site 2
outputs
digital 2U
outputs to plant
Digital 2Y RELAY UNITS

ground 2Z 8-channel (PN LA083352) & 4-channel (LA083351)
relay units complete with indicating LEDs & free-
wheeling protective diodes are available from EPAL.
Figure 9-6 Digital outputs operating relays (current sinks) with pullup via customer’s PSU
SW
+ Customer’s
1P
PSU
R – (7.5V - 28V)
1Q
Site 1
digital
inputs 1R
1S
Digital 1Y
ground 1Z
SW
2P
2Q
Site 2
NOTE
digital
Select resistors R to ensure at
inputs 2R least 2mA wetting current via
contacts SW.
E.g. With 24V supply, input im-

2S pedance = 100k (see spec.),
so max. current without using
resistor = 24V/100k
= 0.24mA, which is too small.
Use R 24V/2mA = 12k
Digital 2Y
(for 2.24mA wetting current).
ground 2Z
Figure 9-7 Digital input contact-sensing using customer’s PSU
Ordering information T640 codes
Chapter 10 ORDERING INFORMATION
ORDERING OPTIONS
The T640 can be ordered as a complete package including sleeve and memory module.
The order codes required for this are given in Table 10-1. Sleeves (T710), security keys
(T950), memory modules (T901), burden resistor/diode kits, and ALIN terminator kits are
separately orderable using the order codes listed in Tables 10-2 to 10-5.
T640 ORDER CODES
CODE DESCRIPTION
Base unit
T640 Integrated Loop Processor
Power supply
MAINS Universal mains 90 to 265 volts ac rms
DC 19 to 55 volts dc power supply
Serial communications
422 RS422 Bi-Synch or MODBUS serial communications
485 RS485 MODBUS comms
ExISB (Not yet available)
— None fitted
Site 1 high-level I/O board
HI 0-5V or 0-10V input range automatically selected by database
HG Jumpers set for 0-1.25V fixed input range
HIB As HI but with internal burden resistors fitted
HGB As HG but with internal burden resistors fitted
Site 2 high-level I/O expansion board [1]
HI Expands board specified in Site 1, but with no burden resistors

HG
HIB Expands board specified in Site 1, but with internal burden resistors fitted
HGB
— No board fitted in Site 2
Site 1 low-level I/O board [2]
TC Thermocouple I/O option

RT (Not yet available)
Site 2 low-level I/O board [2]
TC Thermocouple I/O option

RT (Not yet available)
[1]
The range specified for Site 2 high-level I/O (I or G code) must follow that specified for Site 1
[2]
For standard T640 only; not available for T640-FF version.
continued …
T710 codes Ordering information
… continued
CODE DESCRIPTION
Memory module
M001 2-loop Integrated Loop Processor
M002 4-loop Integrated Loop Processor
M003 (Not yet available)
M004 4-loop Integrated Loop Processor with sequencing
M006 Fixed-function Integrated Loop Processor (High-level I/O only)
— None fitted
Sleeve
T710 Supplied in a T710 sleeve
T750 Supplied in a T750 sleeve
— None supplied
Calibration certificate
CERT Calibration certificate supplied
— None supplied
Configuration sheet
CONF Factory-configured to supplied configuration sheet
— Supplied with I/O settings as specified in the I/O codes
Labelling language
EN English
FR French
GE German
IT Italian
SW Swedish
SP Spanish
PO (Not yet available)
CY (Not yet available)
US American
Example: T640/MAINS/ — /HI/HI/M001/T710/ — / —/EN
Table 10-1 T640 order codes
T710 SLEEVE (ORDERED SEPARATELY)
CODE DESCRIPTION
Base unit
T710 DIN sleeve
Power supply connector assembly
MAINS Universal mains 90 to 265 volts ac rms
DC 19 to 55 volts dc power supply
continued …

Ordering information T950 codes
… continued
CODE DESCRIPTION
Site 1 connector assembly
H High-level I/O
Site 2 connector assembly
H High-level I/O [Only if H specified in Site 1]
— No I/O specified for Site 2
Labelling language
EN English
FR French
GE German
IT Italian
SW Swedish
SP Spanish
US American
Example: T710/DC/H/H/EN
Table 10-2 T710 sleeve order codes
T950 SECURITY KEY
CODE DESCRIPTION
Base unit
T950 Infrared security key
Access
FULL Full access to all parameters provided
PARTIAL Partial access to parameters provided
Area
AREA n Key operates only instruments with specified area code n,
or zero area code. [n =1 to 8]
— Key operates only instruments with zero area code
Labelling language
EN English
FR French
GE German
IT Italian
SW Swedish
SP Spanish
US American
Example: T950/PARTIAL/AREA 3/EN
Table 10-3 T950 security key order codes

T901 codes Ordering information
T901 MEMORY MODULE (ORDERED SEPARATELY)
CODE DESCRIPTION
Base unit
T901 Memory module
Controller function
M001 2-loop control
M002 4-loop control
M003 (Not yet available)
M004 4-loop control with sequencing
M006 Fixed-function Integrated Loop Processor
Labelling language
EN English
FR French
GE German
IT Italian
SW Swedish
SP Spanish
US American
Example: T901/M001/EN
Table 10-4 T901 memory module order codes
BURDEN RESISTOR/DIODE & ALIN TERMINATOR KITS
Encapsulated plug-in modules for insertion in T640’s rear-panel customer screw terminals
are orderable using the codes listed in Table 10-5. Burden resistors, burden diodes, and
ALIN terminating resistors are available.
CODE DESCRIPTION
High-level mA kit
LA 082 728 4-off double 250R burden resistor plug-in modules
2-off burden diode plug-in modules
ALIN terminator kit
LA 082 729 2-off 82R terminating resistor plug-in modules
Table 10-5 Rear-panel plug-in module kits

Index
Index T640-FF REFERENCE MANUAL & USER GUIDE
Symbols Analogue inputs and outputs ............. 2-16

.DBF file ........................................... 5-1 Antistatic bag .................................... 2-7
.FFn ................................................. 5-1 ARCNET ........................................... 7-3
.GWF filename extension ................. 2-22 Area ......................................... 2-7, 4-9
.Lnn ................................................. 6-1 Area number ..................................... 4-9
.RUN ............................................. 2-24 Automatic mode .............................. 3-12
.TPD file .......................................... 2-27
5-digit display ............................ 3-7, 4-2 B
Bad Key ......................................... 4-10
A Bargraph segment ............................. 4-3
Absolute & deviation alarms Bargraph span .................................. 4-2
annunciation ............................... 3-18 Bargraphs ........................................ 3-7
configuring ................................. 3-17 Batteries ........................................... 2-4
Access ...................................... 2-7, 4-9 Battery replacement ......................... 4-10
Access level ...................................... 4-4 Battery-test LED ................................ 4-10
Accessory kit ............................ 2-10, 3-3 Binary RS422 configuration .............. 2-22
AlAck ............................................... 4-7 Bisync Port ........................................ 7-2
Alarm BISYNC protocol ............................... 9-5
absolute & deviation BLOCK ............................................. 4-6
annunciation ............................. 4-4 Block Access mode ............................ 4-6
viewing settings ......................... 4-4 Block-structured strategy ..................... 1-3
absolute/deviation ........................ 4-2 Board-specific parameters ................ 9-10
brownout .................................... 2-27 Burden resistor/diode & ALIN
display & inspection via ALM button . 4-7 terminator kits ............................ 10-4
fields .......................................... 3-10 Burden resistors ................................. 9-9
priorities ....................................... 8-3
relay ............................................ 8-4 C
strategy ........................................ 8-3 Cable screens ................................. 2-16
subfields ..................................... 3-17 Cable size ...................................... 2-10
ALIN ....................................... 5-37, 9-4 Cabling ............................................ 2-8
channel ........................................ 7-2 Cached ............................................ 4-4
comms connections ...................... 2-16 Calibration ..................................... 9-10
peer-to-peer comms ........................ 7-3 procedure ................................... 9-15
terminator kits ............................. 10-4 Cascade interlocking signals
ALIN address .................................. 5-37 — strategy #3 ........................... 5-23
ALIN link .......................................... 1-3 Cascade operation .......................... 5-22
Alkaline manganese batteries ............. 2-4 Cascading a pair of loops ................ 5-23
ALM ................................................. 4-4 Changes logfile ................................. 6-1
ALM (alarm) button ..................... 3-7, 8-4 Character set, dot-matrix display ......... 9-4
ALM_SET .......................................... 4-4 Clamp removal ................................. 2-9
T640-FF Reference Manual & User Guide HA 083 235 U003 Issue 4 Index-1
Index
Clamps ............................................ 2-9 alarm annunciation ........................ 4-4

Cleaning instructions .......................... 2-4 alarm settings, viewing ................... 4-4
Cold start .............................. 2-24, 3-13 bargraphs ..................................... 4-2
Coldstart filename ........................... 2-23 Diagnostic blocks ............................ 5-37
ColdStrt Trying .................. 2-28, 3-6, 8-1 Diagnostic blocks in the T640
Communicating ............................... 5-37 fixed function strategies .............. 5-37
Communications Diagnostics ....................................... 8-1
option jumper link settings ............ 2-22 Digital input contact-sensing
option SW1/2 setting .................... 8-1 using customer’s PSU .................. 9-18
ports ............................................ 7-2 Digital outputs driving plant logic
zero volts schematic ..................... 2-16 using customer’s PSU .................. 9-16
Compressed format ................... 2-23, 5-1 Digital outputs operating relays
Computer remote mode ...................... 4-3 (current sinks) ............................ 9-17
Conductive pollution .......................... 2-3 DIL
Conn. .............................................. 4-6 switchbanks 1 and 2 .................... 2-18
Connection Enquiry mode .................. 4-6 DIL switchbanks ........................ 2-27, 7-3
Connections & wiring ....................... 2-10 Dimensions ....................................... 2-8
Control loop Disconnecting device ......................... 2-3
handling more than one ............... 3-24 Dot-matrix display character set ........... 9-4
Control strategy filename .................. 2-23 DUAL ............................................... 5-1
COSHH statement ............................. 2-4 DUAL_CS ......................................... 5-1
CPU ................................................. 7-1 DUAL_RT .......................................... 5-1
FAIL ...................................... 8-1, 8-4
watchdog ..................................... 8-4 E
Creating your own ‘fixed-function’ Earth connection ................................ 2-2
strategies .................................... 5-2 EEPROM .......................................... 7-2
Customer Electrostatically sensitive
screw terminals ............................. 7-4 components .......................... 2-4, 2-7
terminal designations ................... 5-23 EMC information ............................... 2-1
terminals ....................................... 5-4 Engineering units ............................... 4-2
Customer screw terminals ........ 2-10, 2-11 Err hhhh ........................................... 8-1
Error conditions ............................... 2-28
D Error messages .................................. 8-1
Database Error numbers & their meanings .......... 8-3
access .......................................... 4-4 Expansion I/O board ........................ 9-9
acquisition .................................. 2-24 Expansion-type I/O board ................ 2-18
alarms .......................................... 8-1 External faceplates ............................ 7-2
halt .............................................. 8-4 External ISB .................................... 2-22
inspect mode ................................ 6-1 Extractor tool ............................ 2-10, 3-3
inspecting & editing ..................... 3-14
parameters ................................... 4-4 F
saving ........................................ 3-20 Ferrules .......................................... 2-10
Databases accessible to a keyholder .... 4-9 FFPT .......................................... 1-3, 5-1
Date/time stamped alarms ................. 8-4 FIELD ................................................ 4-6
DC option ....................................... 2-10 Field Access mode ............................. 4-6
Deviation Fields & subfields ............................... 3-9
alarm ........................................... 4-2 File types ................................. 2-23, 7-2
Index-2 T640-FF Reference Manual & User Guide HA 083 235 U003 Issue 4
Index
Filtering .......................................... 5-29 INS button ................................. 4-4, 6-1

Fixed-Function Parameterisation Tool ..... 5-1 Inspect Mode entry ............................ 6-1
Flashing bargraph ............................. 4-2 Inspecting & editing the database ..... 3-14
Flashing LED ..................................... 4-3 Installation ........................................ 2-8
Forced manual mode ......................... 8-5 & startup ...................................... 2-1
Forced mode ..................................... 4-2 category voltages .......................... 2-3
Front panel ....................... 2-16, 4-2, 7-3 safety requirements ........................ 2-2
display Instrument case ................................ 2-16
alarm settings & limits ............... 3-18 Instrument node number ................... 5-37
Full .................................................. 4-9 Instrument supply ............................. 2-10
Full access mode ............................... 4-4 Integral term windup ........................ 5-25
Function blocks .................................. 3-9 Internal Serial Bus (ISB) ...................... 7-2
Fuse ........................................ 2-10, 9-4
J
G JBUS .............................................. 5-37
Gateway file ................................... 2-22 Jumper links .................................... 2-22
GND terminal ................................. 2-16 Jumpers .......................................... 2-16
H K
HALTED ............................................ 8-1 Keeping the product safe .................... 2-4
Handling precautions ........... 2-4, 2-7, 3-3 Key parameters ................................. 4-9
Hardware Killed outputs .................................. 2-24
alarm relay ................................... 8-4
build level ..................................... 2-7 L
configuration ............................... 2-18 Labels .............................................. 2-7
Hardware/software faults ................... 8-1 Limit ................................................. 4-6
High-level I/O ................................... 9-9 LIN .................................................. 1-3
High-level I/O board LIN blocks LINfiler ...................................... 1-3, 5-1
parameter support ...................... 9-10 Local setpoint
High-level I/O boards ...................... 2-14 displaying & altering .................... 3-11
limit ........................................... 3-18
I Logfile ..................................... 2-23, 6-1
I/O LOOP ........................................ 4-4, 4-9
boards ....................................... 2-16 Loop
calibration procedure ................... 9-15 access mode ................................. 4-4
options ....................................... 2-16 fail ............................................... 8-5
site ............................................... 3-4 tagname ....................................... 3-7
sites ............................................. 9-9 update rate ............... 5-14, 5-25, 5-30
sub-assemblies .............................. 7-4 Loop 1 parameters .......................... 5-12
zero volts schematic ..................... 2-16 Loop 2 parameters .......................... 5-21
I/O cards ....................................... 2-24 Loop 3 parameters — strategy #4
I/O circuits ..................................... 9-16 (ratio station) ............................. 5-31
ID Code ........................................... 4-9 Loop 4 parameters .......................... 5-13
ID code ............................................ 2-7 LOOP n ............................................ 4-4
Infrared LED .................................... 4-10 LOOP n message ............................... 4-2
Input ranges ...................................... 9-9 Loop status summary .......................... 9-2
INS ......................................... 3-14, 4-3 LP n ALM ................................... 4-7, 8-2
Index
M Ordering information ....................... 10-1

M (Manual) pushbutton ...................... 3-7 OUTPUT ........................................... 4-3
Main CPU ............................... 2-16, 7-1 Output
Main fuse ....................................... 2-19 bargraph ...................................... 4-3
Main loop display ............................. 4-2 changing ...................................... 4-3
Main processor (CPU) fail ................... 8-5 display ......................................... 4-3
Mains ............................................ 2-10 parameters, quick access ................ 4-3
MAINS option motherboard Overcurrent protection ....................... 2-3
terminal block ............................ 2-11
Mains safety cover ........................... 2-11 P
Manual mode ................................. 3-12 P & I (piping and instrumentation)
MASKED .......................................... 4-3 diagram ...................................... 3-4
Master controller ............................. 5-25 Package contents ............................... 2-7
Master node ..................................... 7-2 Packed format ................................... 5-1
MeasPos ........................................... 4-3 Panel cut-out & dimensions ................. 9-1
Memory ........................................... 7-2 Panel mounting ................................. 2-9
module ............... 2-18, 2-23, 7-2, 8-1 Panel-mounting the T640 .................... 2-8
module label ................................. 2-7 Parameter change ............................. 6-1
module removal ........................... 2-18 Parameterisation tool ......................... 1-3
Misuse of equipment .......................... 2-4 Parameters ........................................ 4-4
MODBUS protocol ............................. 9-6 Partial .............................................. 4-9
Modbus RS422 ............................... 2-22 Partial access mode ........................... 4-4
MODBUS RS422/485 configuration .. 2-22 PID .................................................. 3-4
Modbus RS485 ............................... 2-22 PID_CONN blocks .......................... 5-37
MODBUS/JBUS .............................. 5-37 Power
Mode changes .................................. 4-3 interruptions ................................ 3-13
Modes ............................................. 4-2 supply ............................ 3-1, 7-3, 9-4
Motherboard ........................... 2-18, 7-1 Power input .................................... 2-10
DIL switchbanks ........................... 2-27 Power supply .................................. 2-16
Motherboard customer terminals ......... 5-4 Power-on Reset .................. 2-28, 3-6, 8-1
Motherboard terminal assignments ...... 5-4 Power-up
Mounting clamps ............................... 2-8 & power-fail mode ....................... 3-21
MS_Dmnd ........................................ 4-3 displays ........................................ 8-1
messages ...................................... 3-6
N routine ........................................ 2-24
No Key ............................................ 4-9 Pre-configured strategies ..................... 5-1
NoAlm ............................................. 4-7 Priorities ........................................... 8-3
Node number ................................... 7-2 Process variable alarms .................... 5-14
Normal & inverse ratios ................... 5-29 Protective earth connection ................. 2-2
Normal power-up ............................ 2-28 Pushbutton masking ......................... 3-23
Pushbuttons ....................................... 9-2
O PV
Oerator displays & controls ................ 4-2 tracking of by setpoint .................. 3-22
On/off control ................................. 3-22 PV display ........................................ 4-2
Operating mode selecting ................ 3-12 PV fail mode ................................... 3-22
Options .......................................... 10-1 PV-X bargraph display ....................... 4-2
Order codes ..................................... 2-7 PV-X legend ...................................... 4-2
Index
Q Saving a database .......................... 3-20

Quitting Saving parameter values .................... 5-1
alarm inspection modes .................. 4-7 Screw terminals ................................. 7-4
database access modes ................. 4-6 Security
key ....................................... 4-4, 4-9
R key label ...................................... 2-7
Security key ...................................... 6-1
RAM ................................................ 7-2
Serial comms
Ranges & limits
jumper links ................................ 2-21
configuring ................................. 3-14
option ........................................ 2-22
Ratio
Serial communications ..................... 2-22
normal & inverse ......................... 5-29
Serial number ................................... 2-7
setpoint trim ................................ 5-29
Service and repairs ............................ 2-4
station ........................................ 5-27
SetLocal ............................................ 4-3
Ratio bias ....................................... 5-29
Setpoint
Realtime clock .......................... 2-24, 7-3
changing ...................................... 4-3
Rear-panel
display ......................................... 4-3
customer connections ..................... 9-9
parameters, quick access................ 4-4
plug-in module kits ....................... 10-4
Setup sheet for Loop 3
Records, logfile ................................. 6-1
— strategy #4 (ratio) .................. 5-36
Relay
Setup sheet for Loop 4
alarm ........................................... 8-4
— all strategies .......................... 5-36
watchdog ..................................... 8-4
Setup sheets .................... 5-8, 5-32, 5-34
Relays .............................................. 9-4
Shipping damage .............................. 2-7
Remote mode ........................... 3-13, 4-3
SINGLE ............................................ 5-1
RemoteSP ......................................... 4-3
Single control loop ............................ 3-1
Removing T640 from sleeve .............. 2-10
Site 1 I/O ...................................... 2-11
Ronly ............................................... 4-6
Site 1 I/O customer terminal
RS422 communications ...................... 9-5
assignments ................................. 5-7
RS422 node address ....................... 5-37
Site 2 ............................................. 5-14
RS422/485
terminations ................................ 5-16
comms connections ...................... 2-16
Site 2 I/O ...................................... 2-11
communications ........................... 5-37
Site 2 I/O customer terminal
driver ........................................... 7-2
assignments ............................... 5-17
power supply unit ........................ 2-16
Slave
RS485 communications ...................... 9-5
controller .................................... 5-25
Running a default
node ............................................ 7-2
fixed-function strategy ................... 5-2
Slave/master status .......................... 2-23
Sleeve labels ..................................... 2-7
S
Software ........................................... 9-6
Safe usage of alkaline manganese Software file types ........................... 2-23
batteries ...................................... 2-4 Software issue number ....................... 2-7
Safety SP-W bargraph display ...................... 4-2
& EMC information ........................ 2-1 SP-W legend ..................................... 4-2
cover ......................................... 2-11 Specifications .................................... 9-1
requirements ................................. 2-2 analogue inputs ........................... 9-11
symbols marked on the unit ............. 2-4 current analogue outputs .............. 9-14
Index
digital inputs ............................... 9-15 Tepid

digital outputs ............................. 9-15 data .................................. 2-24, 2-27
dot-matrix display character set ....... 9-4 data file ...................................... 2-23
environmental ............................... 9-1 start ........................................... 3-13
front panel displays ....................... 9-2 TepidSrt Trying ......................... 2-28, 8-1
high-level I/O ............................... 9-9 Terminal
internal burden resistors ............... 9-14 cover ........................................... 2-8
mechanical ................................... 9-1 cover removal ............................. 2-11
power supplies .............................. 9-4 designations ............................... 2-12
relays ........................................... 9-4 Terminals .......................................... 7-4
transmitter power supplies ............ 9-14 Time-stamped alarms ......................... 7-3
voltage analogue outputs .............. 9-14 Tutorial ............................................. 3-1
Strategy #1 ...................................... 3-4
Strategy #1 — Single control loop ....... 5-1 U
Strategy #2 — Dual control loop ....... 5-14 Un Pack Database ............. 2-28, 3-6, 8-1
Strategy #3 — Dual control loop UnAcd ............................................. 4-7
(cascade) .................................. 5-22 Units display .............................. 3-7, 4-2
Strategy #4 — Dual control loop Unlocking the T640 .................. 2-10, 3-3
(Ratio) ....................................... 5-27 Unpacking ........................................ 2-7
Strategy design principles ................... 5-3 Unpacking your T640 ........................ 2-7
SubFd .............................................. 4-6 User
Subfield Access mode ........................ 4-6 alarm ........................................... 8-5
Subfields .......................................... 4-6 task .............................................. 5-8
Summary loop displays ...................... 4-2 startup .................................... 2-24
Supercap .......................................... 7-2
Switch settings ................................... 3-3 V
Switchbanks 1 & 2 ................. 2-20, 2-21 VALUE .............................................. 4-6
Symbols marked on the unit ................ 2-4 Value update mode ........................... 4-6
System filename .............................. 2-23 Ventilation ........................................ 2-3
T W
T221 bridge ..................................... 7-3 Warm start ............................ 2-24, 3-13
T640 WarmStrt Trying ....................... 2-28, 8-1
base unit ...................................... 9-1 Watchdog ........................................ 8-4
connectors .................................. 2-10 failure .......................................... 8-1
internal layout ............................. 2-18 relay ............................................ 3-9
removing from sleeve ..................... 3-3 Watchdog relay contacts ................. 2-21
T640 order codes ............................ 10-2 Wiring .................................... 2-3, 2-10
T710 sleeve order codes .................. 10-3
T901 memory module order codes ..... 10-4 Z
T950 infrared-operating security key ..... 4-9
Zero volts schematic ......................... 2-16
T950 security key order codes .......... 10-3
Tag display ................................ 3-7, 4-2
TCS binary Bisync protocol ............... 5-37

T640FF User Guide and Reference

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T640 (M006)

© 1994-1996 Eurotherm Process Automation Limited. All Rights Reserved.

Issue 4 November 1996 Part Number HA 083 235 U003

Contents T640-FF REFERENCE MANUAL & USER GUIDE

Chapter 1 INTRODUCTION page

Chapter 2 INSTALLATION & STARTUP

Installation ........................................................................................ 2-8

Chapter 3 HANDS-ON TUTORIAL

Configuring the decimal point ............................................ 3-17

Chapter 4 USER INTERFACE

Database access ................................................................................ 4-4

Chapter 5 FIXED-FUNCTION STRATEGIES

Strategy #3 schematic ............................................................... 5-23

Chapter 6 CHANGES LOGFILE

Chapter 7 INSIDE T640

Front panel .................................................................................. 7-3

Chapter 8 ERROR CONDITIONS & DIAGNOSTICS

RS422 communications .................................................................... 9-5

Chapter 10 ORDERING INFORMATION

NETWORK 6000 PROCESS AUTOMATION SYSTEM

OPERATOR COMMAND CONSOLES

DISCRETE DCS INTELLIGENT

Figure 1-1 Network 6000 distributed control system

T640-FF Reference Manual & User Guide Issue 3/A 1-1

Summary of T640-FF’s main features

What’s in this manual

Table 1-1 Topics covered by this manual

1-2 T640-FF Reference Manual & User Guide Issue 3/A

What’s not in this manual

Full block-structured strategy configuration using LINtools

T640-FF Reference Manual & User Guide Issue 3/A 1-3

Chapter 2 INSTALLATION & STARTUP

■ Safety & EMC information

SAFETY & EMC INFORMATION

Installation requirements for EMC

Installation safety requirements

Protective earth connection

The following safety measures should be observed:

■ A switch or circuit breaker complying with the requirements of IEC947-1 and

■ Instrument supply: 85 to 264Vac, 2A, (T).

Installation category voltages

Electrostatic discharge handling precautions

Safety symbols marked on the unit

Caution! Refer to Protective earth Caution! Mains

Alternating current Direct current

Keeping the product safe

Service and repairs

Safe usage of alkaline manganese batteries

ALKALINE MANGANESE BATTERIES — COSHH STATEMENT

ABBREVIATIONS USED IN THIS DOCUMENT

UNPACKING YOUR T640

Figure 2-1 T640 principal dimensions

Figure 2-2 Fitting a clamp to the sleeve

Figure 2-3 Removing a clamp from the sleeve

Removing T640 from sleeve

Extractor tool Slot in Opening

Figure 2-4 Withdrawing T640 from the sleeve

CONNECTIONS & WIRING

Terminal cover removal