A350 Ata 42
A350 Ata 42
A350 Ata 42
Network
CH 42
STUDENT LEARNING OBJECTIVES:
TABLE OF CONTENTS:
Computers only used electronic logic cards. No software.(e.g. MARKER Common Remote Data Concentrators (CRDCs)
BEACON receiver).
Traditionally the function of a Data Concentrator was to convert analog or
Second Generation discrete input data into a digital ARINC 429 protocol such as the SDACS
do on the A330. The CRDCs fulfill this traditional role in addition to
This generation of computers used electronic logic cards hosting software collecting, conversion and exchanges of data between the AFDX network
elements (A/C system application) that were hosted in On-Board and the equipment without AFDX capability such as sensors, switches,
Replaceable Modules (OBRMs) that were line replaceable. Some other potentiometers, cockpit panels, etc. and communicating through ARINC,
parts contained resident software that could only be replaced in the shop. CAN, analog or discrete means. The CRDCs host no avionics application.
The A330 FMGEC is a good example of this type of computer. The
system functions are carried out from the OBRM. The CPIOMs and the CRDCs dialog through the AFDX network. They use
a protocol equivalent to Ethernet communication technology, which is
Third Generation adapted to the aviation constraints (integrity of data, redundancy and
reliability).
Processing and storage resources that use electronic logic cards, resident
software and A/C system application. This application does an A/C
function and can be uploaded into the computer on the flight line. The
A350 FMC is a third generation type computer.
With the new (Fourth Generation) avionics concept, Integrated Modular This technology is called Avionics Full DupleX switched ethernet
Avionics (IMA), most of the A/C systems functions that were done by (AFDX) and is the component that links the IMA together. The AFDX
conventional LRUs are now done by avionics applications. These harnesses will be discussed in more detail later in this chapter.
independent applications are hosted in shared IMA modules called Core
Processing Input/Output Modules (CPIOMs). With the IMA concept, a
smaller number of computers is necessary for the A/C systems. The
maintenance costs are lower as a result.
The CPIOMs and the CRDCs dialog through the AFDX network. They use
a protocol equivalent to Ethernet communication technology, which is
adapted to the aviation constraints (integrity of data, redundancy and
reliability).
INTEGRATED MODULAR AVIONICS
There are seven clusters of CPIOMs divided into two types: Air Conditioning System (ACS)
Cabin Pressure Control System (CPCS)
Type H (12 units) Wing Ice Protection System (WIPS)
Type J (9 units + 1 optional) Supplemental Cooling System (SCS)
Ventilation Control System (VCS)
The CPIOMs are different in the definition of their physical interfaces Overheat Detection System (OHDS)
(I/Os). For example, CPIOM J can generate audio signals (e.g. FWS Engine Bleed Air System (EBAS)
application function), but CPIOMs H can supply a wider variety of signals.
All CPIOMs are installed in the main avionics compartment. CPIOMs H6 host the applications of the systems that follow:
There are three groups (also named clusters) of CPIOMs type H (H3, H4 Brake Control System (BCS)
and H6) and four groups of CPIOMs type J (J1, J2, J5 and J7). Landing Gear Management System (LGMS)
Landing Gear Extension and Retraction System (LGERS)
Each CPIOM is identified by one letter and two digits (e.g. H31). The letter Wheel Steering Control System (WSCS)
gives the CPIOM type H or J. The first digit gives the CPIOM group to
which it belongs from 1 to 7. The second digit gives the CPIOM number in There are four clusters of CPIOMs J (J1, J2, J5 and J7).
this group from 1 to 4.
CPIOMs J1 host the applications of the Flight Warning System (FWS)
The CPIOM-H and CPIOM-J are not interchangeable because they do not
have the same hardware. The CPIOMs of the same type and of the same CPIOMs J2 host the applications of the systems that follow:
group can be swapped with no other requirement than A/C systems
applications uploading. The CPIOMs of the same type but of different Fire Protection System (FPS)
group can be swapped if their core software is uploaded and if the A/C Engine Interface Function (EIF)
system applications are uploaded. Nacelle Anti-Icing (NAI)
Functional Description One CPIOM J5 hosts the applications of the systems that follow:
CPIOMs H3 host the applications of the systems that follow: Air Traffic Control (ATC)
Avionics Communication Router (ACR)
Hydraulic Monitoring and Control (HMC)
Inert Gas Generation System (IGGS) CPIOMs J7 host the applications of the systems that follow:
Door and Slide Control System (DSCS)
Fuel Quantity and Management System (FQMS) Flight Control Unit Back-Up (FCU Backup)
Crew and Cabin Oxygen Flight Control Data Concentrator (FCDC)
Electrical Load Management (ELM)
Exterior Light Controller (ELCO)
Electrical System BITE (ESB)
CORE PROCESSING INPUT/OUTPUT MODULE
The CPIOMs give memory and computation resources to hosted avionics Shells A and B are for non-AFDX signals
applications. Each CPIOM has a set of field loadable software that includes Shell C is for the signals that follow: AFDX inputs/outputs, 28VDC,
a module software and a system software. ground and pin programming
The module software contains: The interactive mode gives a set of interactive functions for aircraft
maintenance and troubleshooting:
Core software that manages CPIOM resources (memory, I/O) and gives
an interface between these resources and the hosted systems CRDC test
Configuration table software which supplies configuration data CRDC interface test
(memory, Central Processing Unit (CPU) time, input/output allocations) Resource BITE memory download
Resource BITE (RB) configuration-table software, which is connected to
the RB The maintenance operator can do a CRDC power-on safety-test to confirm
internal faults detected during flight. Safety tests are also automatic during
The system software includes: CRDC power-up. With safety tests, the operator can make sure that there
is no fault in the CRDC before it starts to operate.
One or more avionics application(s). An application is software which
does a specific avionics function or a part of an avionics function For the CRDC test, all interfaces of the tested CRDC are set to the default
One or more database(s) if applicable configuration. This test is completed in less than 30 seconds.
Component Description The operator can do this test to confirm external faults detected during
flight.
The CPIOM has the electronic components that follow:
The Resource BITE memory download function is used to download the
A core-processor unit board, which includes a processor, memories content of the CRDC RB NVM. The downloaded data is stored in the CMS
and inputs/outputs. This board hosts an Avionics Full Duplex Switched memory and can subsequently be downloaded to a media.
Ethernet (AFDX) end-system board for AFDX communication
An input/output board, which receives, processes and manages the Power Supply
inputs/outputs. This board hosts a power supply board, which generates
the voltages for the module from the 28VDC supply The CPIOMs are supplied with 28VDC through electro-mechanical circuit
breakers or Solid-State Power Controllers (SSPCs).
An interboard for the internal communication between the core-processor
unit board and the inputs/outputs board
CPIOM-H34 is supplied through an external relay to have two power
supplies
CPIOM INTERNAL ARCHITECTURE
General Description
CRDC Types
Hardware for data conversion and I/O processing block, in charge of CRDC BITE
data acquisition, concentration and transfer
A computation part that includes the boolean logic and a gateway to the The BITE function of the CRDC:
AFDX network (AFDX end system)
Makes an analysis of the monitoring and test results of the CRDC
Data Load Generates the related fault messages
Sends these fault messages to the CMS and memorizes them
Each CRDC has three field loadable software units: Dialogs with the CMS to start interactive tests
A core software, which gives a standard and common environment CRDC Power Supply
A configuration table software, which supplies configuration data (input/
output connection and routing, combinatorial logic) CRDCs are supplied with 28VDC through electro-mechanical circuit
A Resource BITE (RB) configuration table software, which contains the breakers or Solid State Power Controllers (SSPC).
list of maintenance messages related to the CRDC
Discrete Output (DSO) Power Supply
It is necessary to upload software to the CRDCs through the Data Loading
and Configuration System (DLCS) after: Some components are electrically supplied by DSO signals from the
CRDC through specific electro mechanical breakers or SSPCs up to 1.5A.
A CRDC replacement, if there is no software pre-loaded or if the
software configuration is incorrect Each C/B or SSPC supplies a group of DSO signals. If there is a fault of
A software update one DSO signal, the CRDC inhibits the DSO-group power supply.
General Description
General Description
Several avionics applications are hosted in the same IMA component. For
this reason, an IMA component failure can be a common cause for several
system failures.
Should this occur, the triggering of multiple ECAM messages can occur.
There is no ECAM message dedicated to each IMA component failure.
A second line in the ECAM message indicates that the root cause is an
IMA common resource failure.
Dispatch Principles
Single or multiple IMA module failures (when one or some modules are
impacted)
ATA XX alarms, triggered or not by IMA module failures.
IMA ALARM MANAGEMENT PRINCIPLES (CONT)
CPIOM H (12)
CPIOM J (10), including one optional (CPIOM J52 (ACR2)
AFDX ARCHITECTURE
The Avionics Full Duplex Switched Ethernet (AFDX) network uses a The AFDX network can manage the data traffic through the VL concept.
technology based on the Ethernet protocol adapted to aeronautical A VL isolates the data transfers between a transmitter and receivers
constraints. It is used for data exchange between computers. (segregated channels within the network).
The AFDX network exchanges operational, maintenance and loading data A VL is shown as a one-way pipe in the network.
between the aircraft computers that have an AFDX interface. A VL has:
The AFDX network users are organized in interconnected functional areas: Mono-directional transfer
One transmitter only
Cockpit Avionics One or more users in receive mode
Flight Controls and Auto Flight A fixed maximum bandwidth
Engine Control A maximum guaranteed transfer time of the network for transmission
Fuel A specific path over the network
Energy One specific identifier
Pneumatic and Cabin
Landing Gear
The AFDX network is also used for communication between the aircraft
systems and the Onboard Information System (OIS) through a Secure
Communication Interface (SCI).
The AFDX network uses the redundancy principle meaning it has two
networks, network A and network B.
The AFDX network includes network nodes, called switches. Users are
physically interconnected through these switches.
Network information data, used to send the AFDX package to the correct
address
Data transmitted in the AFDX frame payload (with optional application
level integrity checking)
A Cyclic Redundancy Check (CRC) for high integrity
AFDX ARCHITECTURE
NETWORK
A350-900 ATA 42 TRAINING MANUAL
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A350-900 ATA 42 TRAINING MANUAL
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Type KB The contact is Quadrax to make 10/100 Mbit/s Ethernet signal compatible
Type KD with the connectors used on AIRBUS aircraft: ARINC 600.
This last one is lighter and is used where the EMIs are high. KD24 will be
used more often than KB24 (independently of the application and location).
Four single stranded wires are equally twisted around a center filler
The individual wires are of AWG 24 and have a silver plated copper core
Type KL: KL24 cables have the same wire properties as KD24 wires, but
the isolation material of KL24 is thinner than the isolation of KD24.
There is a protection tape around all four wires
The shield is made of silver plated copper and the cable is fully insulated
by a light blue sheath on which UV Laser marking can be used. The light
blue color makes an easy identification in the aircraft.
AFDX SWITCHES
The AFDX network includes: All the links operate at a speed of 100 Mbits/s, except the links connected
to the EECs, the EMUs and the ETRACs, which operate at a speed of 10
Mbits/s.
AFDX switches
An AFDX harness
Network Bite Function (NBF)
A Network BITE Function (NBF)
The NBF is hosted in the Avionics Server Function Cabinet (ASFC) of the
The AFDX network includes 14 switches (7 switches on each network). Onboard Information System (OIS). It detects and isolates faults on the
A switch has twenty-four identical full duplex ports (reception and AFDX network.
transmission at the same time).
The AFDX network interconnects the users that have an AFDX interface.
The switch receives the AFDX data on its inputs. It does a check of this All the users are connected to the two networks (A and B) through two
data and uses a configuration table to route them to the outputs. redundant switches.
An AFDX switch has these functions: There are two exceptions, the Engine Monitoring Unit (EMU) and the
Centralized Data Acquisition Unit (CDAU) (except the Digital Flight Data
Connect the users (AFDX end systems) to the network from point to Recorder part), which are connected to network B only.
point with cables
Route data transmitted by the users to the recipient(s) The AFDX network is also organized into SIDE1 and SIDE2 (e.g. AESU1
Do checks of the incoming data flows for integrity and correct format and AESU2), but some systems (PRIM, SEC, ADIRS and FMS) use the
Do a check of the data rate (each link has a specific maximum "Triplex" architecture (three AFDX switch pairs and triple user).
bandwidth)
Give protection against physical or environmental damage from lightning,
short-circuits, unwanted current, etc.
An AFDX switch has two software components:
AFDX SW operational program software
AFDX SW configuration table software.
The AFDX switches are all interchangeable.
(2) AFDX Harness
An AFDX link uses a Star Quad cable with two pairs of wires (one pair for
transmission and one for reception).
AFDX SWITCHES
There is no scheduled maintenance and no inspection task necessary on 1. Operational Program software
the AFDX network. The only required action applicable to the AFDX 2. Configuration Table software
network that is necessary is the upload of the field loadable software after
a removal/installation task (operational software and/or configuration If you upload the software to all the AFDX switches, you must do the
table). The switch upload is done through the DLCS and uses the AFDX upload in three steps, in the sequence that follows:
network itself.
1. AFDX switches 09 and 19
Considering the AFDX network architecture and configuration (VL paths 2. AFDX switches 01, 02, 03, 04, 11, 12, 13 and 14
from SCI to the AFDX switches), a special software uploading sequence, 3. AFDX switches 05, 06, 15 and 16
given in the maintenance documentation, must be followed to make sure
that the network is connected during the uploading operation. All the software must be uploaded from the repository. The NBF software
must be uploaded in the ASFC and an AFDX network Maintenance
All the AFDX switches must be uploaded with the same software Part System Load (MSL) file software must be uploaded in the CMS.
Number (P/N) for the operational software and configuration table. The
Network BITE Function (NBF) has the capability to verify that all the
switches have the same software P/N. Also, each AFDX switch makes
sure that there is compatibility between the loaded operational software
P/N and its hardware P/N at power up.