Tait accessories

TMAA01-01 Line-Interface Board

Installation Instructions

Introduction
Note: These instructions refer to line-interface PCB issue IPN 220-65202-02 or later. On
earlier issue PCBs, SK1 pin 5 is ground.
The TMAA01-01 line-interface board provides both audio D-range hood parts
and digital interfaces for a variety of systems. The interfaces
available are:
■ an isolated 600Ω audio interface which is capable of
both simplex operation on a two-wire system, or duplex
operation on a four-wire system D-range plug
■ a keying interface which allows for two-wire keying or Line-interface board
single line bi-directional keying internal options connector
■ a variable delay timer
■ a logic sense control.

The line-interface board fits inside the radio in the options

cavity and is connected to the main PCB by the internal
options loom. The high-density 15-way D-range connector
mounted on the line-interface board fits through the external external options connector
options connector hole provided in the radio chassis. Installation parts

Important: The radio does not meet the

IP54 protection standard once a line-
interface board has been installed unless the
external options cover seal is installed. external options internal
cover seal options loom

Operation
One of the control head function keys may be programmed to toggle the line-interface
board on and off. When the function key LED is glowing, the line-interface board is on and
when the LED is off, the line-interface board is off.

Antistatic Precautions
Important: This equipment contains devices that are susceptible to static charges. The
procedures outlined in this installation guide should therefore be carried out in a static-safe
environment. You can obtain information on antistatic precautions and the dangers of
electrostatic discharge (ESD) from standards such as ESD S4.1-1997 (revised) or BS EN
100015-4 1994. The Electrostatic Discharge Association website is http://www.esda.org/.
402-00012-02 www.taitworld.com
 Adjustment Points on the Line-Interface Board
The following table describes the line-interface adjustment points. Adjustments are made by setting
the DIP switches on S1 to either “on” or “off” and by three variable resistors (RV1, RV2 and RV3).
Line-interface board adjustment points

Function Selection 1 Selection 2

two-wire audio interface DIP1 on DIP2 off
four-wire audio interface DIP1 off DIP2 on
line-interface board - top side
busy/gate = busy DIP3 on DIP4 off
busy/gate = rx-gate DIP3 off DIP4 on
busy/gate logic (active high) DIP5 on DIP6 off
busy/gate logic (active low) DIP5 off DIP6 on
bi-directional keying line DIP7 on
two-wire keying DIP 7 off
enable gate/keying delay DIP8 on
gate/keying delay adjust RV1
audio line out level adjust RV2
audio line in level adjust RV3
time delay range W1 open

Test Equipment Setup

The following diagram shows the setup of test equipment used when adjusting RV1, RV2 and RV3.
Line-interface test equipment setup

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Radio Configuration
The line-interface board configuration must be completed before the board is installed in
the radio, as the top side of the line-interface board is not accessible once the board is screwed
to the radio lid.
To configure the line-interface board, carry out the following steps.
1. Program the radio in which the line-interface board is being installed with default line-
interface test settings. The default test settings are explained in the following tables.
Line-interface default test settings in the Programmable I/O form, Digital tab:

Pin Direction Label Action Active Debounce Signal State Mirrored

IOP_GPIO1 Input None External PTT 1 Low 60 None None
IOP_GPIO2 Output 0 No Action Low None None None
IOP_GPIO3 Output BUSY Busy Status High None None None
IOP_GPIO4 Output FKEY F1 Key Statusa Low None Latching None
a. One of the four control head function keys may be selected to control the line-interface AUX
line, which turns the line-interface board on and off. For the associated LED to reflect the status
of the line-interface board, the Function Key Action field on the Key Settings form must be
set to Action Digital Output Line.

Line-interface settings in the Programmable I/O form, Audio tab :

Rx/PTT Type Tap In Tap In Type Tap In Unmute Tap Out Tap Out Type Tap Out Unmute

Rx None A-Bypass In On PTT R7 D - Split Busy Detect

EPTT1 T5 A-Bypass In On PTT None C-Bypass 0 On PTT

Line-interface settings in the PTT form, External PTT (1) tab:

Field Setting

Advanced PTT PTT Transmission Type Voice

Audio Source Audio Tap In

2. Set the DIP switches on the line-interface board (S1) to the following default test settings:
■ DIP1 on (two-wire audio interface) ■ DIP5 off (busy/gate logic active low)
■ DIP2 off ■ DIP6 on
■ DIP3 off ■ DIP7 off (two-wire keying)
■ DIP4 on (busy/gate = rx-gate) ■ DIP8 off (time delay disabled)

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3. Disassemble the radio in order to gain access to the options cavity. For detailed disassem-
bly instructions, refer to the disassembly procedure in the service manual.
Connect the internal options loom between SK2 on the line-interface board and SK102
on the radio’s main PCB.
4. Set up the test equipment shown in the diagram on page 2, and follow the adjustment
procedure for RV1, RV2 and RV3 described in the following section.

Setting the Keying Time Delay (RV1)

The keying time delay circuit is used to prevent the burst of noise occurring before a mobile
is able to mute the audio when the carrier signal disappears. The keying time delay is used
in conjuction with the keying signal (SK1 pin 1).
1. Set DIP8 on.
2. Adjust RV1 for the required time delay.
Rotate RV1 clockwise to increase the delay, and counterclockwise to reduce the delay.
Note: If the W1 link is fitted, the maximum time delay available is reduced from 5 seconds
to approximately 2.5 seconds.

link W1

Setting the Line Output Level (RV2)

1. Monitor the line output (SK1 pins 14 and 15).
2. Apply an on-channel signal from the RF signal generator at an output level of -47dBm,
modulated to 60% of system deviation, at 1kHz AF.
3. Adjust the RV2 for a line output level of -10dBm.

Setting the Line Input Level (RV3)

1. Apply a line input signal of -10dBm and key the transmitter.
■ For a two-wire configuration: apply the line input signal to pins 14 and 15 on SK1.
■ For a four-wire configuration: apply the line input signal to pins 4 and 10 on SK1.
2. Adjust RV3 until 60% of system deviation at 1kHz is achieved.

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Installing the Line-Interface Board
Note: The line-interface board link options must be set before the board is installed in the
radio, as the top side of the line-interface board is not accessible once the board is screwed
to the radio lid.

Parts Required
The following table describes the parts required to install an line-interface board in a radio.
The parts marked with an asterisk (*) are not shown in the diagram on page 6, and are used
to connect to the radio’s external options connector.
Line-interface installation parts required
Quantity Internal Part Number Description Reference
1 362-01111-XXa foam seal d
1 362-01108-XXa cover seal 1!
2 347-00011-00 4-40x3/16 screws 1@
2 354-01043-00 screw-lock fasteners h
4 349-02062-00 M3x8 screws j
*1 240-00010-80 D-range plug —
*1 240-06010-29 D-range hood —

a. Contact Technical Support for the exact IPN (Internal Part Number)

Installation Procedure
1. Disassemble the radio in order to gain access to the options cavity.
For detailed disassembly instructions, refer to the disassembly procedure in the
service manual.
The circled numbers in the following instructions refer to items in the diagram on page 6.
2. Remove the top cover and lid b from the radio to access the options cavity.
3. Remove the external options connector bung c, if it is fitted.
4. On the inside of the radio lid place the foam seal d over the external options connector
cavity e.
5. With the top side of the line-interface board f facing the radio lid, guide the external
options connector g into the external options connector cavity.
6. Screw the external options connector to the radio lid using the two screw-lock
fasteners h.
Tighten the fasteners to a torque of 0.9N·m (8lbf·in).

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 Important: The external options connector screw-lock fasteners must be tightened
correctly before screwing the line-interface board onto the mounting posts i.
7. Screw the line-interface board to the mounting posts on the radio lid using four M3x8
self-tapping screws j.
Tighten the M3x8 screws to a torque of 1.9N·m (17lbf·in)
Important: For the line-interface board to be installed correctly in the radio’s
options cavity, the internal options connector loom 1) must be looped in the way
shown in the diagram below.
8. Plug the unattached end of internal options connector loom 1) into the internal options
connector on the radio main PCB.
9. Refit the radio lid and top cover to the radio and screw the external options cover seal
1! over the external options connector, using the two 4-40x3/16 screws 1@.
Line-interface board installation

c 1@ h b
e
1!

i
d f

g
1)
j
b radio lid h screw-lock fasteners
c external options connector bung i mounting posts
d foam seal j M3x8 self-tapping screws
e external options connector cavity 1) internal options loom
f line-interface board 1! external options cover seal
g external options connector 1@ 4-40x3/16 screws

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Interface Specifications
The following tables summarize the signals used for the line-interface board on the internal
options connector (SK2 on the line-interface board) and the external options connector
(SK1 on the line-interface board).
Internal options connector (SK2)— pins and signals

Line-interface
Pin Radio signal Description
signal

1 13V8_SW 13V8 FROM RADIO Switched 13V8 supply from the radio
2 AUD_TAP_OUT AUDIO TAP OUT Programmable tap point out of the receive or
1&1* transmit audio chain.

1%1^ 3 AGND AGND Analogue ground

1#1$ 4 AUX_MIC_AUD — Not connected

1!1@ 5 RX_BEEP_IN — Not connected

J1) 6 AUD_TAP_IN AUD_TAP_IN Programmable tap point into the receive or
HI transmit audio chain.

FG 7 RX_AUD — Not connected

DE 8 RSSI — Not connected
BC 9 IOP_GPIO1 PTT FROM OPT IOP_GPIO1 from the radio
3V3 logic level, 5V tolerant
top view 10 IOP_GPIO2 SECONDARY BUSY IOP_GPIO2 from the radio
3V3 logic level, 5V tolerant
11 IOP_GPIO3 BUSY IOP_GPIO3 from the radio
3V3 logic level, 5V tolerant
12 IOP_GPIO4 AUX IOP_GPIO4 from the radio
3V3 logic level, 5V tolerant
13 IOP_GPIO5 GPIO5 IOP_GPIO5 from the radio
3V3 logic level, 5V tolerant
14 IOP_GPIO6 — Not connected
15 IOP_GPIO7 — Not connected
16 DGND AGND Analogue ground
17 IOP_RXD RXD Asynchronous serial port - receive data
18 IOP_TXD TXD Asynchronous serial port - transmit data

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External options connector (SK1)—pins and signals

Pin Signal Description

1 KEYING Signal line keying

2 RS-422/RS-232 Serial data TX-/RS-232 TXD
11 RS-422 Serial data TX+
3 PTT-IN Bi-directional keying input
4 4W_LINE_IN - 4-wire line in negative
front view
10 4W_LINE_IN + 4-wire line in positive
5 RS-422/RS-232 Serial data RX+/RS-232 RXD
6 RS-422 Serial data RX-
7 GND Ground
8 — Not connected
9 13V8 FROM RADIO Switched 13.8V supply from the radio
12 BUSY/GATE Busy or receiver gate output. 5V CMOS logic
level.
13 — Not connected
14 4W_LINE_OUT - 4-wire line out negative or 2-wire line in/out
negative
15 4W_LINE_OUT + 4-wire line out positive or 2-wire line in/out
positive

More Information
Refer to your radio provider for more information about this product.

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