DOC AIRBUS | AMM A320FDISPLAY MANAGEMENT COMPUTER (DMC) / LIQUID CRYSTAL DISPLAY (LCD) CONTROL AND INTERCONNECTION - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
A. EIS Sections
(1) EIS breakdown
Here after are listed all the EIS sections as well as a summary or their contents:
31-60-00 Electronic Instrument System (EIS)
Here after are listed all the EIS sections as well as a summary or their contents:
31-60-00 Electronic Instrument System (EIS)
- The purpose of this document is to give a general description of the EIS (EIS components, display functions, reconfiguration capabilities...).
31-61-00 Electronic Instrument System (EIS)/ Control - The purpose of this document is to give a description of the EIS Controls.
31-62-00 Display Management Computer (DMC) - Acquisition/Interface - The purpose of this document is to give the detailed characteristics of all the Input/Output signals of the DMCs. This document does not deal with the DMC/DU connections (Ref. to 31-63-00).
- The purpose of this document is to give the detailed description of the DMC/DU, the Inputs/Outputs of the DUs and the DMC/DU interconnection.
31-64-00 Primary Flight Display (PFD) - The purpose of this document is to give the detailed description of the PFDs, the logics and the associated controls.
- The purpose of this document is to give the detailed description of the NDs, the logics and the associated controls.
31-66-00 Engine/Warning Display (EWD) - The purpose of this document is to give the detailed description of the EWD, the logics and the associated controls.
31-67-XX System Display (SD) - The purpose of this document is to give the detailed description of the SD, the reasons for the colors changes of the graphic symbols and parameters, the associated controls.
- The purpose of this document is to give the detailed operation of the various switching possibilities (manual or automatic reconfiguration) and the associated DMC/DU connections.
31-69-00 EIS test/Built-In Test Equipment (BITE) - The purpose of this document is to give the description of the DMC BITE for maintenance purpose.
2. Component location
The 3 DMCs are mounted in the electronic rack of the avionics compartment. The six display units are mounted in the instrument panel of the cockpit.
** ON A/C NOT FOR ALL The 3 DMCs are mounted in the electronic rack of the avionics compartment. The six display units are mounted in the instrument panel of the cockpit.
EIS Component Location3. System description
The EIS display functions are performed by the 3 DMCs and the 6 DUs.
The DMCs receive data from different avionics systems in the aircraft, decode them and process them in such a way so that the externally connected full color DUs in the cockpit can use them to generate symbols and pictures on their LCD displays.
In normal operation, each DMC, with respect to sensor and computer inputs, acquires data/parameters through its ONSIDE sources to generate the symbologies of the displays presented on its associated display units.
The OFFSIDE sources and/or THIRD sources (if any) are redundancy information sources.
In normal operation, each DMC drives the following display units:
The EIS display functions are performed by the 3 DMCs and the 6 DUs.
The DMCs receive data from different avionics systems in the aircraft, decode them and process them in such a way so that the externally connected full color DUs in the cockpit can use them to generate symbols and pictures on their LCD displays.
In normal operation, each DMC, with respect to sensor and computer inputs, acquires data/parameters through its ONSIDE sources to generate the symbologies of the displays presented on its associated display units.
The OFFSIDE sources and/or THIRD sources (if any) are redundancy information sources.
In normal operation, each DMC drives the following display units:
- the DMC 1 drives the CAPT PFD DU, the CAPT ND DU, the EWD and the SD
- the DMC 2 drives the F/O PFD DU and the F/O ND DU
- the DMC 3 is a hot spare
A. DMC description
The 3 DMCs are identical and interchangeable.
The DMCs are able to perform the EFIS function or the ECAM function.
Each DMC is independent from the other and has its own:
The 3 DMCs are identical and interchangeable.
The DMCs are able to perform the EFIS function or the ECAM function.
Each DMC is independent from the other and has its own:
- power supply module
- acquisition modules
- processing channel.
B. DU description
The 6 DUs are identical and interchangeable.
Each DU receives digital signals from its related DMC through an A629 Link and also through a particular bus (A453) for the weather radar link.
These digital signals convey instructions and data corresponding to the displays to be presented on the DUs.
The 6 DUs are identical and interchangeable.
Each DU receives digital signals from its related DMC through an A629 Link and also through a particular bus (A453) for the weather radar link.
These digital signals convey instructions and data corresponding to the displays to be presented on the DUs.
(1) DU description
The 6 DUs are identical and interchangeable.
Each DU receives digital signals from its related DMC through an A629 Link, and also through a particular bus (A453) for the weather radar link.
These digital signals convey instructions and data corresponding to the displays to be presented on the DUs.
The 6 DUs are identical and interchangeable.
Each DU receives digital signals from its related DMC through an A629 Link, and also through a particular bus (A453) for the weather radar link.
These digital signals convey instructions and data corresponding to the displays to be presented on the DUs.
C. DMC Technical Data
(1) Housing
- size: 6 MCU
- color: brown.
- Number of boards:
on the face, 5 boards
on the back, 1 mother boards and protection boards. - Number of connectors:
1 ARINC 600, size 3. - Total weight:
5.5 kg.
(a) Input capacity
- discrete: 108 (type: open/ground or 28VDC/open)
- ARINC 429: 99 channels (low speed or high speed)
- ARINC 629: 8 channels (high speed)
- ARINC 453: 4 channels
(b) Output capacity
- discrete: 13 (type: open/ground or 28VDC/open)
- ARINC 429: 8 channels (low speed or high speed)
- ARINC 629: 2 channels
- ARINC 453: 1 channel
- RS232: 2 channels for flight test only
- ETHERNET: 2 channels for data loading
(c) Cooling
Standard ARINC 600 cooling.
Standard ARINC 600 cooling.
(2) DU
(a) Size of the screen
The available size of the screen is a flat square of 6.25 X 6.25 inches, slightly larger than the former CRT technology.
The available size of the screen is a flat square of 6.25 X 6.25 inches, slightly larger than the former CRT technology.
(b) Weight
7.6 kg
7.6 kg
(c) Input capacity
- discrete: 18 (type: open/ground or 28VDC/open)
- ARINC 429: 2 channels (low speed or high speed)
- ARINC 629: 2 channels used, 3 full provision channels and wrap around
- ARINC 453: 1 channel
- discrete: 1 (type: 28VDC/open)
- analog DC: 3 plus 2 reference voltages and one cell provision
(d) Output capacity
- A629: 1
- ARINC 429: 1 channel fot flight test
- discrete: 4 full provision
- RS232: 1 channel for flight test
- video SMPTE259: 2 channels (input/output) and one spare for video DU.
(3) DMC Description
The DMC is composed of 6 printed circuit boards arranged as follows:
Five operational boards are connected mechancally and electrically to a mother board which takes the rear part of the unit.
The DMC is composed of 6 printed circuit boards arranged as follows:
Five operational boards are connected mechancally and electrically to a mother board which takes the rear part of the unit.
(a) ICU Board
This mother board gathers all connections between the operational boards and the connection between the operational boards and the power supply board. Also, the connections between each operational board and the rear connector of the unit are achieved by the mother board, mainly the INPUT/OUTPUT busses and discretes. The lightning protections and the EMI filters are parts of this ICU board.
This mother board gathers all connections between the operational boards and the connection between the operational boards and the power supply board. Also, the connections between each operational board and the rear connector of the unit are achieved by the mother board, mainly the INPUT/OUTPUT busses and discretes. The lightning protections and the EMI filters are parts of this ICU board.
(b) Power supply board
This power supply board ensures that all necessary voltages to the proper operation of each board are provided. To this aim, the voltages 115V X 400 Hz, available at the rear connector level are converted into usable voltages for the operational boards.
This power supply board ensures that all necessary voltages to the proper operation of each board are provided. To this aim, the voltages 115V X 400 Hz, available at the rear connector level are converted into usable voltages for the operational boards.
(c) IO1 and IO2 boards
These are the INPUT/OUTPUT boards, the operational interface between the processor boards and the other A/C systems. ARINC inputs are demodulated and then sent to specific ATINC controllers. These controllers, which manage inputs and outputs write the inputs onto some specific mailboxes accessible by the central processor. Symmetrically, the contollers read ARINC outputs, already written by the processor in its own maibox. The contents of the maibox is modulated and then sent to the other A/C systems by an ARINC output.
These are the INPUT/OUTPUT boards, the operational interface between the processor boards and the other A/C systems. ARINC inputs are demodulated and then sent to specific ATINC controllers. These controllers, which manage inputs and outputs write the inputs onto some specific mailboxes accessible by the central processor. Symmetrically, the contollers read ARINC outputs, already written by the processor in its own maibox. The contents of the maibox is modulated and then sent to the other A/C systems by an ARINC output.
(d) CPU1 and CPU2 boards
The main functions of the DMC are performed by these processor boards: the gathering of data necessary to the image drawing, the conversion from A429 to A629 format for the DU use, the conversion from A629 to A429 for the external circuit use, the transfer of data to the DU, the computations necessary to the teleloading process and the BITE function. The functions of the CPU is performed by software, running in a processor. The code of this processor is stored in the code memory and the data in the data memory. The processor uses code and data to execute the software.
The main functions of the DMC are performed by these processor boards: the gathering of data necessary to the image drawing, the conversion from A429 to A629 format for the DU use, the conversion from A629 to A429 for the external circuit use, the transfer of data to the DU, the computations necessary to the teleloading process and the BITE function. The functions of the CPU is performed by software, running in a processor. The code of this processor is stored in the code memory and the data in the data memory. The processor uses code and data to execute the software.
(4) Display Unit description
The Display Unit, also called LCDU, to differentiate with the technology of the former CRT, is a display equipment including the technology of the back lighted active matrix liquid crystal. This technology includes a triple matrix; each single point of the matrix (the pixel) is a filter to the three fundamental colors (that's why the matrix is triple); each point of the array (the RGB pixel) is triggerable by a set of row drivers at the top, and a set of line drivers at the side. A set of two drivers define an X/Y coordinate which, when triggered together act on the intersect point to filter the light coming from the back in order to produce any sort of color with a large range of intensity for that point, thus taking part in the drawing of an already designed image if all the other points of the matrix are used likewise.
All sorts of sketches can be drawn in this manner to feature for the pilot:
the A/C attitude (PFD), the A/C en route trajectory (ND), the display of the A/C engines parameters (EWD) and also all sorts of sketches in order to feature the A/C systems behaviour at any moment of the flight (SD).
The Display Unit, also called LCDU, to differentiate with the technology of the former CRT, is a display equipment including the technology of the back lighted active matrix liquid crystal. This technology includes a triple matrix; each single point of the matrix (the pixel) is a filter to the three fundamental colors (that's why the matrix is triple); each point of the array (the RGB pixel) is triggerable by a set of row drivers at the top, and a set of line drivers at the side. A set of two drivers define an X/Y coordinate which, when triggered together act on the intersect point to filter the light coming from the back in order to produce any sort of color with a large range of intensity for that point, thus taking part in the drawing of an already designed image if all the other points of the matrix are used likewise.
All sorts of sketches can be drawn in this manner to feature for the pilot:
the A/C attitude (PFD), the A/C en route trajectory (ND), the display of the A/C engines parameters (EWD) and also all sorts of sketches in order to feature the A/C systems behaviour at any moment of the flight (SD).
(5) DU Mechanical unit
The mechanical unit consits of:
The several subassemblies are housed in the mechanical unit, they include:
The mechanical unit consits of:
- a structure which ensures the mechanical strength of the DU and holds in place all the subassemblies
- a cover which ensures the protection of the subassemblies and the air tightness of the DU (reduction of the ventilation air leaks).
The several subassemblies are housed in the mechanical unit, they include:
- the screen and LAM assembly
- the BLM assembly
- the PSM assembly
- the PPM assembly
- the GPM assembly
- the VPM assembly
- the ICM assembly
- the HEATER assembly
(a) LAM assembly
The LAM assembly includes the screen of 6.25 X 6.25 inches which is a flat surface and the triple matrix. It receives the RGB data and several clocks signals (line, frame, pixel frequency) and continuously displays the RGB pixels.
Each pixel is triggered by a row driver (horizontal coordinate) and by a column driver. The column driver are linked to CDB board, and the row drivers are linked to a RDB board. An HEATER device is provided to ensure the proper operation of the matrix, while a temperature sensor ensures the temperature control. Two light sensors just below the screen allow light intensity produced to follow the external lighting conditions.
The LAM assembly includes the screen of 6.25 X 6.25 inches which is a flat surface and the triple matrix. It receives the RGB data and several clocks signals (line, frame, pixel frequency) and continuously displays the RGB pixels.
Each pixel is triggered by a row driver (horizontal coordinate) and by a column driver. The column driver are linked to CDB board, and the row drivers are linked to a RDB board. An HEATER device is provided to ensure the proper operation of the matrix, while a temperature sensor ensures the temperature control. Two light sensors just below the screen allow light intensity produced to follow the external lighting conditions.
(b) BLM assembly
This assembly provides permanent light to the LCD display. It is composed of an array of lamps powered and managed by a dimming module. The dimming module contains a processor that receives luminance orders from the processing module the PPM, elaborated with brightness orders coming from the DU control knob and the light level information coming from the DU front face sensors. The dimming module generates the relevant order to the lamps.
This assembly provides permanent light to the LCD display. It is composed of an array of lamps powered and managed by a dimming module. The dimming module contains a processor that receives luminance orders from the processing module the PPM, elaborated with brightness orders coming from the DU control knob and the light level information coming from the DU front face sensors. The dimming module generates the relevant order to the lamps.
(c) PSM assembly
The PSM assembly provides all the necessary voltages for the DU to operate properly
The PSM assembly provides all the necessary voltages for the DU to operate properly
(d) PPM assembly
the PPM assembly manages the I/O interface with the A/C: discrete, analog, A429, A629.
It also manages bitmap input using A629 and transfer to the GPM. It performs pre processing of the graphic parameters, and the general LCD management.
the PPM assembly manages the I/O interface with the A/C: discrete, analog, A429, A629.
It also manages bitmap input using A629 and transfer to the GPM. It performs pre processing of the graphic parameters, and the general LCD management.
(e) GPM assembly The GPM assembly generates the image to be displayed. It is composed of two identical synchronized channels working in parallel, each one dedicated to the generation of one image column over two. The graphic CPU functions are performed by software. The code and data of these two processors are stored in the graphic memories. They allow to execute the software program. The image generation function is divided in the following subfunctions:
symbology pixel generation
WXR pixel generation
Bitmap pixel generation
MGM memories management
mixing
symbology pixel generation
WXR pixel generation
Bitmap pixel generation
MGM memories management
mixing
- symbomogy pixel generation
Each graphic CPU reads data provided by the processing module in its graphic memory and generates the associated symbology. - WXR pixel generation
A453 input is collected by each MGM, which writes the data in the graphic memories. Then the CPUs read, processes, write them in secondary graphic memories before their transfer to the WXR part of the MGM memory - Bit map pixel generation
Bitmap data are selected from the mailbox of the A629 controller, then written in graphic memories, to be transfered in the bitmap part of the MGM memory. - MGM memory management
Each MGM memory is composed of two memory modules (double page frame buffer) cyclically performing writing or reading/erasing tasks. For symbology, each graphic CPU writes the generated pixels in the write page. At the end of the writing(end of LCD cycle), it sends an order of permutation to its MGM. At the same time, each MGM reads the generated pixels in the read page , in order to mix them, and then erase them. It permutes the two pages, as soon as it receives the order from the graphic CPU and the status of the other MGM (ready for permutation). For WXR and bitmap the process is slower, and pixels are written in the two pages in order for MGM to read them, whatever the status of the considered page towards the symbology (writing or reading). - Mixing
The mixing is performed by the MGM, which manages the following inputs:
symbology (highest priority)
WXR
bitmap
real time video (lowest priority)
The symbology, WXR and bitmap pixels are read by the MGM in its memory (read page). Video pixels, processed by VPM, are directly mixed by the MGM (with video DU) .
The resulting RGB data (MGM output) of each graphic channel are mutiplexed and sent to the LAM assembly.
(6) DMC Housing
- size: 6 MCU
- color: brown.
- Number of connectors:
1 ARINC 600, size 3. - Total weight:
5.5 kg.
(a) The same connector is used for inputs and outputs. It is a 67-contact male connector, type ARINC 404.
Through this connector, the signals below are routed:
Through this connector, the signals below are routed:
- power supplies
- A629 links
- WXR
- discretes/pin prog/reconfiguration
- brightness signals.
- video signals (special coaxial terminals) with video DU
(8) DMC connector description
One single connector of the type ARINC 600 gathers all the electrical links necessary to the various DMC functions.
The connector is made up of five shells. The four upper shells are dedicated to the functional links. The lower left is dedicated to the power supply links.
One single connector of the type ARINC 600 gathers all the electrical links necessary to the various DMC functions.
The connector is made up of five shells. The four upper shells are dedicated to the functional links. The lower left is dedicated to the power supply links.