DOC AIRBUS | AMM A320FAUDIO MANAGEMENT - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
A. Functions
The audio management system provides the means for using:
The audio management system provides the means for using:
(1) All the radio communication, SATCOM and radio navigation facilities installed on the aircraft:
- In transmission mode: it collects the microphone inputs of the various crew stations and directs them to the communication systems.
- In reception mode : it collects the audio outputs of the communication systems and the navigation receivers and directs them to the various crew stations.
(2) The flight interphone system:
- Telephone links between the various crew stations in the cockpit.
- Telephone links between the cockpit and the ground crew from the external power receptacle.
(3) The SELCAL (Selective Calling) system:
- Visual and aural indication of calls from ground stations equipped with a coding device used by the aircraft installation.
(4) Certain calls:
- Visual indication of the ground crew and the Cabin Attendants' calls.
2. System Description
The system comprises:
** ON A/C NOT FOR ALL The system comprises:
Audio Integrating - Block Diagram- 1 AMU
- 2 hand microphone receptacles (CAPT and F/O)
- 2 loud speaker potentiometers with incorporated switches
- 2 radio PTT switches
- 1 jack for the ground crew
- 1 AUDIO SWITCHING selector switch
- 1 SELCAL code panel.
NOTE: In addition, the system uses :
- 2 loud speakers which are part of the central warning system (Flight Warning Computer, ATA 31-53-00, Circuit WW)
- 3 oxygen mask microphones which are part of the oxygen system (OXYGEN-ATA 35-00-00, Circuit HM)
- 2 relay boxes which are part of the DMC system (Display Management Computer-ATA 31-63-00, Circuit WT)
- FLIGHT/GROUND information from the LGCIU (Landing Gear Control and Interface Unit - ATA 32-31-00, Circuit GA).
NOTE: System provision are provided for the installation of an audio control panel in the avionics compartment.
System provision includes:
System provision includes:
- a jack panel
- a blanking place
- a circuit breaker.
3. Component Location
| FIN | FUNCTIONAL DESIGNATION | PANEL | ZONE | ACCESS DOOR | ATA REF |
|---|---|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||||
| 1RN | AMU | 81VU | 127 | 23-51-34 | |
| 2RN1 | ACP-CAPT | 11VU | 210 | 23-51-12 | |
| 2RN2 | ACP-F/O | 11VU | 210 | 23-51-12 | |
| 2RN3 | ACP-3RD OCCPNT | 20VU | 210 | 23-51-12 | |
| 3RN | SELCAL CODE PNL | 127 | 23-51-13 | ||
| 10RN1 | STOWAGE BOX-OXY MASK, CAPT | 101VU | 211 | 35-12-41 | |
| 10RN2 | STOWAGE BOX-OXY MASK, F/O | 700VU | 212 | 35-12-41 | |
| 10RN3 | STOWAGE BOX-OXY MASK, 3RD OCCPNT | 700VU | 212 | 35-12-41 | |
| 16RN | SEL SW-AUDIO SWITCHING | 48VU | 210 | 23-51-00 | |
| 14RN | JACK-FLT INTPH | 108VU | 120 | 23-51-00 | |
| 15RN1 | POT-LOUD SPEAKER, CAPT | 301VU | 211 | 23-51-00 | |
| 15RN2 | POT-LOUD SPEAKER, F/O | 500VU | 212 | 23-51-00 | |
| 17RN1 | RCPT-BOOMSET, CAPT | 61VU | 211 | 23-51-00 | |
| 17RN2 | RCPT-BOOMSET, F/O | 60VU | 212 | 23-51-00 | |
| 17RN3 | RCPT-BOOMSET, 3RD OCCPNT | 62VU | 212 | 23-51-00 | |
| 18RN1 | JACK-HEADSET, CAPT | 61VU | 211 | 23-51-00 | |
| 18RN2 | JACK-HEADSET, F/O | 60VU | 212 | 23-51-00 | |
| 18RN3 | JACK-HEADSET, 3RD OCCPNT | 62VU | 212 | 23-51-00 | |
| 18RN5 | JACK-HEADSET, SUPPLEMENTARY | 15VU | 211 | 23-51-00 | |
| 19RN1 | RCPT-HAND MIC, CAPT | 17VU | 211 | 23-51-00 | |
| 19RN2 | RCPT-HAND MIC, F/O | 16VU | 212 | 23-51-00 | |
| 19RN3 | RCPT-HAND MIC, 3RD OCCPNT | 62VU | 212 | 23-51-00 | |
| 7WW | LOUD SPEAKER-CAPT | 831 | 211 | 31-53-21 | |
| 8WW | LOUD SPEAKER-F/O | 831 | 212 | 31-53-21 | |
A. Audio Management System
(1) The Audio Management Unit (AMU) 1RN is located in the avionics compartment in the aft electronics rack 80VU on shelf 81VU.
(2) The three Audio Control Panels (ACP) are identified and located as follows:
- 2RN1 - center pedestal 11VU, Captain side,
- 2RN2 - center pedestal 11VU, First Officer side,
- 2RN3 - overhead panel 20VU.
(3) These receptacles and jacks panels are identified and located as follows:
- 17RN1 (boomset receptacle) and 18RN1 (headset jack) on overhead panel 61VU, Captain side,
- 17RN2 (boomset receptacle) and 18RN2 (headset jack) on overhead panel 60VU, First Officer side,
- 17RN3 (boomset receptacle), 18RN3 (headset jack) and 19RN3 (hand mic receptacle) on panel 62VU on the right rear wall in the cockpit.
(4) The supplementary headset jack 18RN5 is located on the left rear console, panel 15VU.
(5) The two hand mic receptacles are identified and located as follows:
- 19RN1 on left console, panel 17VU, Captain side,
- 19RN2 on right console, panel 16VU, First Officer side.
(6) The two loud speaker potentiometers with incorporated switches are identified and located as follows:
- 15RN1 on instrument panel, Captain side, panel 301VU,
- 15RN2 on instrument panel, First Officer side, panel 500VU.
(7) The two radio PTT switches are identified and located as follows:
- 11RN on side stick hand-grip, Captain side, 191VU
- 12RN on side stick hand-grip, First Officer side, 180VU.
(8) The three oxygen-mask stowage-boxes are identified and located as follows:
- 10RN1 on left side console 101VU, Captain side,
- 10RN2 on right side console 700VU, First Officer side,
- 10RN3 on right side console 700VU beside the First Officer oxygen mask.
(9) The flight interphone jack for the ground crew 14RN is located on the external power panel 108VU.
(10) The AUDIO SWITCHING selector switch 16RN is located on the overhead panel 48VU.
(11) The SELCAL code panel 3RN is located in the avionics compartment, above the aft electronics rack 80VU.
NOTE: Full provision is made for the installation of an audio control panel in the avionics compartment comprising the following equipment:
- 17RN4 (boomset receptacle), 18RN4 (headset jack) and 19RN4 (hand mic receptacle) located on the panel 63VU in the avionics compartment above the rack 80VU.
Remark: This panel also comprises a connector 3RJ for connecting a boomset to the service interphone circuit, circuit RJ, ATA 23-44. - the blanking plate is located on the panel 63VU in the avionics compartment above the electronics rack 80VU.
4. Power Supply
The system components are supplied with 28VDC from busbar 1PP and essential busbar 4PP via 2 sub-busbars 101PP and 401PP respectively.
The system components are supplied with 28VDC from busbar 1PP and essential busbar 4PP via 2 sub-busbars 101PP and 401PP respectively.
A. Busbar 101PP
- Supply of the 3rd Occupant ACP (2RN3) through the AMU via circuit breaker 6RN.
- Supply of the optional 5th Occupant and Avionics Bay ACPs (2RN5, 2RN4) through the AMU via respective circuit breakers 20RN and 7RN.
B. Busbar 401PP
- Supply of the Captain ACP (2RN1), of the audio board A (Captain and Avionics Bay) and of the SELCAL board via circuit breaker 4RN.
- Supply of the 1st Officer ACP (2RN2), of the audio board (F/O and 3rd Occupant) and of the BITE board via circuit breaker 5RN.
NOTE: Circuit breakers 4RN and 5RN are located on the overhead panel 49VU.
Circuit breakers 6RN and 7RN are located on the rear wall, on panel 121VU.
Circuit breakers 6RN and 7RN are located on the rear wall, on panel 121VU.
5. Interface
A. ACP/AMU Interface
(1) Structure of message
The messages exchanged between the AMU and the ACP are transmitted in compliance with ARINC Specification No. 429 at a low frequency (12 KHz).
Item A.
For a transmission rate of 12 KHz, the elementary bit time is:
1/12 KHz = 83.3 microseconds.
As a word comprises 32 bits:
t1 = 32 X 83.3 microseconds = 2.67 ms
and as a word is transmitted every 10 ms:
t2 = 10 ms.
The time between 2 words is:
t2 - t1 = 7.33 ms.
The messages exchanged between the AMU and the ACP are transmitted in compliance with ARINC Specification No. 429 at a low frequency (12 KHz).
Item A.
For a transmission rate of 12 KHz, the elementary bit time is:
1/12 KHz = 83.3 microseconds.
As a word comprises 32 bits:
t1 = 32 X 83.3 microseconds = 2.67 ms
and as a word is transmitted every 10 ms:
t2 = 10 ms.
The time between 2 words is:
t2 - t1 = 7.33 ms.
(2) Protocol for data exchange between AMU and ACP
A dialog exists between the ACP and the AMU in order to establish a looped circuit.
The ACP transmits three types of words:
Structure of dialog
Item B
A dialog exists between the ACP and the AMU in order to establish a looped circuit.
The ACP transmits three types of words:
- 1st type of word designated word O or status request word.
- 2nd type of word designated volume control word.
- 3rd type of word designated coded data of ACP P/N.
Structure of dialog
Item B
(a) ACP-to-AMU connection
The ACP transmits a word every 10 ms in the following order:
The ACP transmits a word every 10 ms in the following order:
| . Status request word Word 0 |
| . VHF1 volume control word Word 1 |
| . VHF2 volume control word Word 2 |
| . VHF3 volume control word Word 3 |
| . HF1 volume control word Word 4 |
| . HF2 volume control word Word 5 |
| . INT volume control word Word 6 |
| . CAB volume control word Word 7 |
| . PA volume control word Word 8 |
| . VOR1 volume control word Word 9 |
| . VOR2 volume control word Word 10 |
| . MKR volume control word Word 11 |
| . LS volume control word Word 12 |
| . SATCOM 1 volume control word Word 13 |
| . SATCOM 2 volume control word Word 14 |
| . ADF1 volume control word Word 15 |
| . ADF2 volume control word Word 16 |
| . PART NUMBER part 1 word Word 17 |
| . PART NUMBER part 2 word Word 18 |
- This cyclic transmission continues provided that no volume control modification or any other data modification appears.
- As soon as a modification is detected at any data level, the system emits the concerned word every 10 ms until this data is fixed (end of modifications).
- However, a complete basic cycle is emitted after 210 ms to up-date, if applicable, other data.
- Moreover, the status request word will be emitted systematically every 210 ms irrespective of the data modifications in progress.
(b) AMU-to-ACP connection
These words arrive every 210 ms (word 2 arrives 10 ms after word 1) and give the SELCAL call status, transmission channel return and pin-programming status.
These words arrive every 210 ms (word 2 arrives 10 ms after word 1) and give the SELCAL call status, transmission channel return and pin-programming status.
(3) Types of word
(a) Words from ACP
1 First type of words
(designated word 0 or status request word)
(designated word 0 or status request word)
| b b b b b b b b b b |
| 32 31 28 27 12 11 10 9 8 1 |
| ---------------------------------------------------------------------------- |
| ! P ! Reseved ! ER ER ! R ! SDI ! LABEL ! |
| ! ! ! 15-----------------------------------0 ! T ! ! 300 ! |
| ---------------------------------------------------------------------------- |
| Program identification |
| - b1 to b8 : Label : Byte which defines the type of data sent. |
| Label 300 is assigned to word 0. |
| - b9 : SDI : Bit sets to 1. |
| - b10 : SDI : Bit sets to 0. |
| - b11 : Status of ACP test ( in progress : 1, not in progress : 0) |
| - b12 to b27 : Error : Gives the result of a self-test and a fault |
| diagnosis. |
| ------------------------------------------------------------------- |
| ! b! b! b! b! b! b! b! b! b! b! b! b! b! b! b! b! ERROR ! |
| !27!26!25!24!23!22!21!20!19!18!17!16!15!14!13!12! ! |
| !--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!-----------------! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! 1! RAM ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! 1! ! MICROPROCESSOR ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! 1! ! ! CHECKSUM ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! 1! ! ! ! CONVERSION ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! ! ! ! ! ! 1! ! ! ! ! ARINC RECEPTION ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! ! ! ! ! 1! ! ! ! ! ! RECEPTION ERROR ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! ! ! ! 1! ! ! ! ! ! ! COLUMN 1 ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! ! ! 1! ! ! ! ! ! ! ! COLUMN 2 ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! ! 1! ! ! ! ! ! ! ! ! COLUMN 3 ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! 1! ! ! ! ! ! ! ! ! ! COLUMN 4 ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! 1! ! ! ! ! ! ! ! ! ! ! LINE ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! 1! ! ! ! ! ! ! ! ! ! ! ! PIN-PROGRAMMING ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! 1! ! ! ! ! ! ! ! ! ! ! ! ! VOICE ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! 1! ! ! ! ! ! ! ! ! ! ! ! ! ! EMISSION ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! 1! ! ! ! ! ! ! ! ! ! ! ! ! ! ! CONVERSION ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! 1! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! KEYBOARD ! |
| ------------------------------------------------------------------- |
| - b28 to b31 : Reserved (set to 0) |
| - b32 : Parity bit (odd). |
2 Second type of word
(designated volume control word or word n)
- b11 to b14 : Status of transmission keyboard (Ref. transmission selection table) ACP transmission selection-table
(designated volume control word or word n)
| b b b b b b b b b b b b b b b b |
| 32 31 28 27 26 25 24 17 16 15 14 11 10 9 8 1 |
| ---------------------------------------------------------------------------- |
| ! ! !R ! ! ! ! ! ! ! ! ! |
| ! ! ER ER ER ER !E !V !ON/!D D D D D D D D!I !R ! E E E E ! ! ! |
| !P ! !S ! ! ! !N !A ! ! SDI ! LABEL ! |
| ! ! 20 19 18 17 !E !O !OFF!7 6 5 4 3 2 1 0!T !D ! 3 2 1 0 ! ! ! |
| ! ! !T ! ! ! ! ! ! ! ! ! |
| ---------------------------------------------------------------------------- |
| Program Identification |
| - b1 to b8 : Label : Byte which defines the type of data sent |
| (Ref. label table) |
| - b9 to b10 : SDI : Bits which identify the relevant system |
| -------------------------------------------------------------- |
| ! ! LABEL CODE ! SDI BITS ! |
| ! !----------------------!-----------! |
| ! ! ARINC ! BYTE IN ! b10 ! b9 ! |
| ! ! STANDARD !HEXADECIMAL! ! ! |
| -------------------------------------------------------------- |
| !Status request word ! 300 ! 0 3 ! 0 ! 1 ! |
| ! ! ! ! ! ! |
| !VHF1 volume control word ! 210 ! 1 1 ! 0 ! 1 ! |
| ! ! ! ! ! ! |
| !VHF2 volume control word ! 210 ! 1 1 ! 1 ! 0 ! |
| ! ! ! ! ! ! |
| !VHF3 volume control word ! 210 ! 1 1 ! 1 ! 1 ! |
| ! ! ! ! ! ! |
| !HF1 volume control word ! 211 ! 9 1 ! 0 ! 1 ! |
| ! ! ! ! ! ! |
| !HF2 volume control word ! 211 ! 9 1 ! 1 ! 0 ! |
| ! ! ! ! ! ! |
| !INT volume control word ! 215 ! B 1 ! 0 ! 1 ! |
| ! ! ! ! ! ! |
| !CAB volume control word ! 215 ! B 1 ! 1 ! 0 ! |
| ! ! ! ! ! ! |
| !PA volume control word ! 212 ! 5 1 ! 1 ! 1 ! |
| ! ! ! ! ! ! |
| !VOR1 volume control word ! 213 ! D 1 ! 0 ! 1 ! |
| ! ! ! ! ! ! |
| !VOR2 volume control word ! 213 ! D 1 ! 1 ! 0 ! |
| ! ! ! ! ! ! |
| !MKR volume control word ! 213 ! D 1 ! 1 ! 1 ! |
| ! ! ! ! ! ! |
| !ILS volume control word ! 217 ! F 1 ! 0 ! 0 ! |
| ! ! ! ! ! ! |
| !SATCOM 1 volume ctl word ! 220 ! 0 9 ! 0 ! 1 ! |
| ! ! ! ! ! ! |
| !SATCOM 2 volume ctl word ! 220 ! 0 9 ! 1 ! 0 ! |
| ! ! ! ! ! ! |
| !ADF1 volume control word ! 212 ! 5 1 ! 0 ! 1 ! |
| ! ! ! ! ! ! |
| !ADF2 volume control word ! 212 ! 5 1 ! 1 ! 0 ! |
| ! ! ! ! ! ! |
| !PART NUMBER part 1 word ! 302 ! 4 3 ! 0 ! 0 ! |
| ! ! ! ! ! ! |
| !PART NUMBER part 2 word ! 302 ! 4 3 ! 0 ! 1 ! |
| -------------------------------------------------------------- |
| --------------------------------------------------------- |
| ! b14 ! b13 ! b12 ! b11 ! ! |
| --------------------------------------------------------! |
| ! 0 ! 0 ! 0 ! 0 ! No channel selected ! |
| ! ! ! ! ! ! |
| ! 0 ! 0 ! 0 ! 1 ! VHF1 ! |
| ! ! ! ! ! ! |
| ! 0 ! 0 ! 1 ! 0 ! VHF2 ! |
| ! ! ! ! ! ! |
| ! 0 ! 0 ! 1 ! 1 ! VHF3 ! |
| ! ! ! ! ! ! |
| ! 0 ! 1 ! 0 ! 0 ! HF1 ! |
| ! ! ! ! ! ! |
| ! 0 ! 1 ! 0 ! 1 ! HF2 ! |
| ! ! ! ! ! ! |
| ! 0 ! 1 ! 1 ! 0 ! INT ! |
| ! ! ! ! ! ! |
| ! 0 ! 1 ! 1 ! 1 ! CAB ! |
| ! ! ! ! ! ! |
| ! 1 ! 0 ! 0 ! 0 ! PA ! |
| ! ! ! ! ! ! |
| ! 1 ! 0 ! 0 ! 1 ! SATCOM 1 ! |
| ! ! ! ! ! ! |
| ! 1 ! 0 ! 1 ! 0 ! SATCOM 2 ! |
| ! ! ! ! ! ! |
| ! 1 ! 0 ! 1 ! 1 ! SATCOM 1 DEACTIVATED ! |
| ! ! ! ! ! ! |
| ! 1 ! 1 ! 0 ! 0 ! SATCOM 2 DEACTIVATED ! |
| ! ! ! ! ! ! |
| ! 1 ! 1 ! 1 ! 1 ! INVALID ! |
| --------------------------------------------------------- |
| - b15 : Radio PTT switch (active at 1) |
| - b16 : Interphone PTT switch (active at 1) |
| - b17 to b24 : Byte which defines the volume control value of the |
| channel defined by the label and the SDI |
| - b25 : Bit which defines the ON or OFF status of the |
| reception channel (1 for ON) |
| - b26 : Bit which sets the VOICE filter into service |
| (active at 1) |
| - b27 : Call reset (active at 1) |
| - b28 to b31 : Error : Bits which give a fault diagnosis |
| (Ref. Error bits Table) |
| Signification of error bits |
| ---------------------------------------------------------------------------- |
| ! b31 ! b30 ! b29 ! b28 ! ! |
| !-------!-------!-------!-------!------------------------------------------! |
| ! ! ! ! 1 ! Volume control deviation > 70 in HEX ! |
| ! ! ! ! ! ! |
| ! ! ! 1 ! ! Transmission pushbutton switch inhibited ! |
| ! ! ! ! ! ! |
| ! ! 1 ! ! ! VOICE pushbutton switch inhibited ! |
| ! ! ! ! ! ! |
| ! 1 ! ! ! ! RESET pushbutton switch inhibited ! |
| ---------------------------------------------------------------------------- |
| - b32 : Parity bit. |
3 Third type of word: Words 17 and 18
(designated coded data of ACP P/N)
The words 17 and 18 comprise coded data that identify ACP P/N. This P/N is made up of two numerical parts (Part 1 and Part 2) separated from each other by two letters.
(designated coded data of ACP P/N)
The words 17 and 18 comprise coded data that identify ACP P/N. This P/N is made up of two numerical parts (Part 1 and Part 2) separated from each other by two letters.
| - Example: ACP P/N 2788 AF 01 |
| 2788 ............. : Part 1 |
| 01 ............. : Part 2 |
| A ............. : First letter |
| F ............. : Second letter . |
a Word composition
- Word 17
b31 b25 b24 b21 b20 b17 b16 b13 b12 b11 ------------------------------------------------------------------------------- 7 6 5 4 3 2 1 8 4 2 1 8 4 2 1 8 4 2 1 ------------------------------------------------------------------------------- ISO 5 BCD BCD BCD 1st Letter THOUSANDS HUNDREDS TENS RESERVED PART 1 PART 1 PART 2 ------------------------------------------------------------------------------- - Word 18
b31 b25 b24 b21 b20 b17 b16 b13 b12 b11 ------------------------------------------------------------------------------- 7 6 5 4 3 2 1 8 4 2 1 8 4 2 1 8 4 2 1 ------------------------------------------------------------------------------- ISO 5 BCD BCD BCD 2nd Letter TENS UNITS UNITS RESERVED PART 1 PART 1 PART 2 -------------------------------------------------------------------------------
- Word 17
b31 b25 b24 b21 b20 b17 b16 b13 b12 b11 ------------------------------------------------------------------------------- 7 6 5 4 3 2 1 8 4 2 1 8 4 2 1 8 4 2 1 ------------------------------------------------------------------------------- 1 0 0 0 0 0 1 0 0 1 0 0 1 1 1 0 0 0 0 A 2 7 0 ------------------------------------------------------------------------------- - Word 18
b31 b25 b24 b21 b20 b17 b16 b13 b12 b11 ------------------------------------------------------------------------------- 7 6 5 4 3 2 1 8 4 2 1 8 4 2 1 8 4 2 1 ------------------------------------------------------------------------------- 1 0 0 0 1 1 0 1 0 0 0 1 0 0 0 0 0 0 1 F 8 8 1 -------------------------------------------------------------------------------
(b) Word from AMU (status word)
The AMU transmits two words designated status words.
These two words are called "word 1" and "word 2".
The AMU transmits two words designated status words.
These two words are called "word 1" and "word 2".
1 Word 1
Its structure is as follows:
Label 301 is assigned to the status word.
Its structure is as follows:
| b b b b b b b b b b b b b b b |
| 32 31 30 29 25 24 17 16 15 14 11 10 9 8 1 |
| ------------------------------------------------------------------- |
| !P !0 !0 ! ! ! ! ! ! ! |
| ! ! ! !A A A A A! ! A A! E E E E ! 0 0 ! LABEL ! |
| ! ! ! !4 3 2 1 0! ! 6 5! 3 2 1 0 ! ! 301 ! |
| ------------------------------------------------------------------- |
Label 301 is assigned to the status word.
| - b1 to b8 : Label 301 : Byte which defines the type of data sent |
| - b9 : Status of SATCOM 1 call (ON = 1) |
| - b10 : Status of SATCOM 2 call (ON = 1) |
| - b11 to b14 : Return of transmission keyboard status for check in |
| ACP (the truth table is the same as the one used in |
| the volume control word) |
| - b15 : Status of MECH call (ON = 1) |
| - b16 : Status of ATT call (ON = 1) |
| - b17 to b22 : Status of PIN PROGRAMMING |
| ------------------------------------------------------------------ |
| ! b22 ! b21 ! b20 ! b19 ! b18 ! b17 ! ! |
| -----------------------------------------------------------------! |
| ! ! ! ! ! ! 1 ! VHF3 installed ! |
| ! ! ! ! ! ! ! ! |
| ! ! ! ! ! 1 ! ! HF1 installed ! |
| ! ! ! ! ! ! ! ! |
| ! ! ! ! 1 ! ! ! HF2 installed ! |
| ! ! ! ! ! ! ! ! |
| ! ! ! 1 ! ! ! ! ADF2 installed ! |
| ! ! ! ! ! ! ! ! |
| ! ! 1 ! ! ! ! ! MLS (unused) ! |
| ! ! ! ! ! ! ! ! |
| ! 1 ! ! ! ! ! ! Lock PA ! |
| ------------------------------------------------------------------ |
| - b23 : ACP test requested by the BITE |
| - b24 : Status of PIN PROGRAMMING "SATCOM 1" (ON = 1) |
| - b25 to b29 : Status of calls |
| --------------------------------------------------------- |
| ! b29 ! b28 ! b27 ! b26 ! b25 ! ! |
| --------------------------------------------------------! |
| ! ! ! ! ! 1 !VHF1 ! |
| ! ! ! ! ! ! ! |
| ! ! ! ! 1 ! !VHF2 ! |
| ! ! ! ! ! ! ! |
| ! ! ! 1 ! ! !VHF3 ! |
| ! ! ! ! ! ! ! |
| ! ! 1 ! ! ! ! HF1 ! |
| ! ! ! ! ! ! ! |
| ! 1 ! ! ! ! ! HF2 ! |
| --------------------------------------------------------- |
| - b30 : Status of VOICE (ON = 1) |
| - b31 : Status of PIN PROGRAMMING "SATCOM 2" (ON = 1) |
| - b32 : Parity bit. |
2 Word 2
Its structure is as follows:
Label 303 is assigned to word 2.
Its structure is as follows:
| b b b b b b b b b b b b b b b |
| 32 31 25 24 23 22 21 20 19 18 17 16 9 8 1 |
| ------------------------------------------------------------------- |
| !P ! ! ! ! ! ! ! ! ! ! ! ! ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! LABEL ! |
| ! ! ! ! ! ! ! ! ! ! ! ! ! 303 ! |
| ------------------------------------------------------------------- |
Label 303 is assigned to word 2.
| - b1 to b8 : Label 303 : Byte which defines the type of data sent |
| - b9 to b15 : Reserved |
| - b16 : Status of PIN PROGRAMMING "SATCOM FUNCTION" (ON = 1) |
| - b17 to b18 : Status of the green bars on the SATCOM 1 transmission pushbutton |
| switch |
| --------------------------------------------------------------- |
| ! b18 ! b17 ! Status of the green bars on the SATCOM 1 ! |
| ! ! ! transmission pushbutton switch ! |
| !-------!-------!---------------------------------------------! |
| ! 0 ! 0 ! OFF ! |
| ! ! ! ! |
| ! 0 ! 1 ! flashes 1 cycle/s (HOLD function) ! |
| ! ! ! ! |
| ! 1 ! 0 ! flashes 2 cycles/s (AIR/GROUND call) ! |
| ! ! ! ! |
| ! 1 ! 1 ! ON ! |
| --------------------------------------------------------------- |
| - b19 to b20 : Status of the green bars on the SATCOM 2 transmission pushbutton |
| switch |
| --------------------------------------------------------------- |
| ! b20 ! b19 ! Status of the green bars on the SATCOM 2 ! |
| ! ! ! transmission pushbutton switch ! |
| !-------!-------!---------------------------------------------! |
| ! 0 ! 0 ! OFF ! |
| ! ! ! ! |
| ! 0 ! 1 ! flashes 1 cycle/s (HOLD function) ! |
| ! ! ! ! |
| ! 1 ! 0 ! flashes 2 cycles/s (AIR/GROUND call) ! |
| ! ! ! ! |
| ! 1 ! 1 ! ON ! |
| --------------------------------------------------------------- |
| - b21 : Status of SATCOM 1 discrete No. 1 (0 = ground, 1 = open) * |
| - b22 : Status of SATCOM 1 discrete No. 2 (0 = ground, 1 = open) * |
| - b23 : Status of SATCOM 2 discrete No. 1 (0 = ground, 1 = open) * |
| - b24 : Status of SATCOM 2 discrete No. 2 (0 = ground, 1 = open) * |
| - b25 to 31 : Reserved |
| - b32 : Parity bit. |
B. AMU/ CFDIU Interface
The input and output connection with the CFDIU is a Type 1 System.
The system is capable of a two-way communication with the CFDIU.
The AMU transmits labels 350, 356 and 377 on the output bus (labels 350 and 377 have additional functions).
Besides the maintenance function the AMU BITE circuit ensures two additional functions:
The input and output connection with the CFDIU is a Type 1 System.
The system is capable of a two-way communication with the CFDIU.
The AMU transmits labels 350, 356 and 377 on the output bus (labels 350 and 377 have additional functions).
Besides the maintenance function the AMU BITE circuit ensures two additional functions:
- it transmits the status of the pin-program
- it transmits an identification message.
(1) Transmission of pin program
- Every 120 ms the BITE circuit generates a message which gives the installation status of certain equipment (VHF3 - HF1 - HF2 - ADF2 - MLS (unused) - SATCOM).
This message is generated from the information sent by the SELCAL card which receives the pin-program. It is sent to the CFDIU. - The CFDS requires this information in order to transmit this information to the relevant circuits such as the Radio Management Panels (RMP) and the SDAC.
- This information is transmitted in 32-bit word form in compliance with ARINC 429 with label 350.
Word structure is as follows:b b b b b b b b b b b b b b b b 32 31 30 23 18 17 16 15 14 13 12 11 10 9 8 1 -------------------------------------------------------------------- ! ! ! !M !S !S ! A !H !H !V ! ! ! ! !P ! 0 0 !0 0 0 0 0 0 0 0 !L !A !A ! D !F !F !H ! 0 !0 ! LABEL ! ! ! ! !S !T !T ! F 2 !2 !1 !F ! ! ! 350 ! ! ! ! ! !C !C ! ! ! !3 ! ! ! ! ! ! ! ! !O !O ! ! ! ! ! ! ! ! ! ! ! ! !M !M ! ! ! ! ! ! ! ! ! ! ! ! !2 !1 ! ! ! ! ! ! ! ! -------------------------------------------------------------------- - Bit at logic 0 : the equipment is not installed
- Bit at logic 1 : the equipment is installed.
(2) Transmission of identification message
Every component connected to the maintenance centralized system transmits an identification message to facilitate and shorten the test procedures.
The identification code assigned to the AMU is: 6A.
This information is transmitted in 32-bit word form in compliance with ARINC 429 with label 377.
Word structure is as follows:
Every component connected to the maintenance centralized system transmits an identification message to facilitate and shorten the test procedures.
The identification code assigned to the AMU is: 6A.
This information is transmitted in 32-bit word form in compliance with ARINC 429 with label 377.
Word structure is as follows:
| b b b b b b b b b b b b |
| 31 30 29 19 18 15 14 11 10 9 8 1 |
| ------------------------------------------------------------------- |
| !P ! 0 0 !0 0 0 0 0 0 0 0 0 0 0! 6 ! A ! 0 ! 1 ! LABEL 377 ! |
| ------------------------------------------------------------------- |
C. Output Discretes
| ------------------------------------------------------------------------------- |
| NAME ELECTRICAL LEVEL TO SIGNAL STATUS |
| ------------------------------------------------------------------------------- |
| ALTERNATE PTT CABIN GND/O.C CIDS 1/2 XMSN |
| ACTIVATED = GND |
| ALTERNATE PTT HF 1 GND/O.C HF 1 XCVR XMSN |
| ACTIVATED = GND |
| ALTERNATE PTT HF 2 GND/O.C HF 2 XCVR XMSN |
| ACTIVATED = GND |
| ALTERNATE PTT PA GND/O.C CIDS 1/2 XMSN |
| ACTIVATED = GND |
| ALTERNATE PTT VHF 1 GND/O.C VHF 1 XCVR XMSN |
| ACTIVATED = GND |
| ALTERNATE PTT VHF 2 GND/O.C VHF 2 XCVR XMSN |
| ACTIVATED = GND |
| ALTERNATE PTT VHF 3 GND/O.C VHF 3 XCVR XMSN |
| ACTIVATED = GND |
| SELCAL INTMT BUZZER CTL GND/O.C FWC BUZZER ACTIVATED |
| = GND |
| ATTND RESET OUTPUT GND/O.C CIDS 1/2 SC RESET |
| ACTIVATED = GND |
D. Output Analog Signals
| ------------------------------------------------------------------------------- |
| NAME ELECTRICAL LEVEL TO SIGNAL STATUS |
| ------------------------------------------------------------------------------- |
| CABIN MIKE 0/0.250 V CIDS Modulation |
| CVR AUDIO 3rd OCCPNT 0/5.5 V CVR Modulation |
| CVR AUDIO CAPTAIN 0/5.5 V CVR Modulation |
| CVR AUDIO F/0 0/5.5 V CVR Modulation |
| HF 1 MIKE 0/0.250 V HF 1 XCVR Modulation |
| HF 2 MIKE 0/0.250 V HF 2 XCVR Modulation |
| PASSENGER ADDRESS MIKE 0/0.250 V CIDS Modulation |
| VHF 1 MIKE 0/0.250 V VHF 1 XCVR Modulation |
| VHF 2 MIKE 0/0.250 V VHF 2 XCVR Modulation |
| VHF 3 MIKE 0/0.250 V VHF 3 XCVR Modulation |
6. Component Description
A. Audio Control Panel-Function FIN: 2-RN-1 FIN: 2-RN-2 FIN: 2-RN-3 FIN: 2-RN-5
The ACP supplies the means:
The ACP supplies the means:
- to use the various radio communication and radio navigation facilities installed on the aircraft for transmission and reception of the audio signals
- to display the various calls (SELCAL, ground crew call and calls from the Cabin Attendants).
B. Audio Control Panel-Mechanical description-Face
The face comprises:
The face comprises:
- 7 rectangular electronic pushbutton switches for selection of the transmission channels. They also indicate the SELCAL, ground crew and Cabin Attendant calls.
- 3 rectangular electronic pushbutton switches separated from the 7 other pushbutton switches. One of this pushbutton switch selects the transmission channel for Passenger Address (PA) announcements, the 2 others are used for the selection of the SATCOM channels (they also indicate the call on these channels).
- 15 round pushbutton switches with associated potentiometers for selection and adjustment of the audio level on the reception channels.
- 1 INT/RAD selector switch which selects the radio and flight interphone functions. It is a three-position switch: stable in INT and center position, unstable in RAD position.
- 1 rectangular VOICE pushbutton switch which connects a filter into the audio circuits of the VOR and ADF navigation systems.
- 1 RESET rectangular electronic pushbutton switch which is used to cancel the lighted calls.
C. Audio Control Panel-Functional description
NOTE: With the SATCOM system, communications are managed by the audio system, and subscriber's telephone number is initialized by the MCDU (Ref. ATA 23-82) and managed by the SDU (Ref. ATA 23-28).
D. Audio Control Panel-Functional description-Transmission channel selection
To connect the microphones and the PTT command to the selected transmitter, push one of the 10 rectangular pushbutton switches: VHF1- VHF2- VHF3- HF1- HF2- INT- CAB- PA- SATCOM 1- SATCOM 2.
The three green bars on the pushbutton switch, which indicate that selection has been accepted, come on.
An electronic device inhibits simultaneous selection of several transmitters and therefore several transmission pushbutton switches cannot be selected at the same time.
When a new transmission function is selected, the light of the selected pushbutton switch comes on and the function is selected. At the same time, the previously selected pushbutton switch is disabled and its three green bars go off.
To interrupt a communication, push the transmission pushbutton switch which is already selected: the function is disabled. The indicator light which indicates transmission goes off and no transmission function is selected on the ACP.
For SATCOM communications only, the HOLD function can be used.
The aim of this function is to hold the current SATCOM communication temporarily while using another communication means (e.g VHF). Thus, a SATCOM call being established (green bars on), action on another transmission pushbutton switch causes the three green bars of the concerned transmission channel to come on and stay on (normal ACP operation). Then, the green bars of the SATCOM transmission pushbutton switch start to flash (flashing rate: 1 on/off cycle per second). If the SATCOM channel is selected again or if the concerned transmission pushbutton switch is pushed a second time, the corresponding channel is no longer selected and the green bars of the SATCOM transmission pushbutton switch come on and stay on.
To interrupt a SATCOM communication, the selected transmission pushbutton switch must be also pushed (in this case, the SATCOM transmission pushbutton switch). In the same way, the indicator light goes off, but the communication remains possible for three seconds. When the SATCOM transmitter operates in HOLD function, it is necessary to return to the SATCOM transmission and to push the SATCOM transmission pushbutton switch again.
When the call termination request comes from the ground, the green bars go off.
The rectangular PA pushbutton switch is unstable, i.e. it must be held pushed during the complete transmission time. This avoids unwanted transmission on the PA circuit. This unstable operation can be inhibited by the AMU pin-program.
To connect the microphones and the PTT command to the selected transmitter, push one of the 10 rectangular pushbutton switches: VHF1- VHF2- VHF3- HF1- HF2- INT- CAB- PA- SATCOM 1- SATCOM 2.
The three green bars on the pushbutton switch, which indicate that selection has been accepted, come on.
An electronic device inhibits simultaneous selection of several transmitters and therefore several transmission pushbutton switches cannot be selected at the same time.
When a new transmission function is selected, the light of the selected pushbutton switch comes on and the function is selected. At the same time, the previously selected pushbutton switch is disabled and its three green bars go off.
To interrupt a communication, push the transmission pushbutton switch which is already selected: the function is disabled. The indicator light which indicates transmission goes off and no transmission function is selected on the ACP.
For SATCOM communications only, the HOLD function can be used.
The aim of this function is to hold the current SATCOM communication temporarily while using another communication means (e.g VHF). Thus, a SATCOM call being established (green bars on), action on another transmission pushbutton switch causes the three green bars of the concerned transmission channel to come on and stay on (normal ACP operation). Then, the green bars of the SATCOM transmission pushbutton switch start to flash (flashing rate: 1 on/off cycle per second). If the SATCOM channel is selected again or if the concerned transmission pushbutton switch is pushed a second time, the corresponding channel is no longer selected and the green bars of the SATCOM transmission pushbutton switch come on and stay on.
To interrupt a SATCOM communication, the selected transmission pushbutton switch must be also pushed (in this case, the SATCOM transmission pushbutton switch). In the same way, the indicator light goes off, but the communication remains possible for three seconds. When the SATCOM transmitter operates in HOLD function, it is necessary to return to the SATCOM transmission and to push the SATCOM transmission pushbutton switch again.
When the call termination request comes from the ground, the green bars go off.
The rectangular PA pushbutton switch is unstable, i.e. it must be held pushed during the complete transmission time. This avoids unwanted transmission on the PA circuit. This unstable operation can be inhibited by the AMU pin-program.
E. Audio Control Panel-Functional description-Selection of reception
The round reception pushbutton switches serve to select and adjust the audio levels.
When an audio channel is selected, the related reception pushbutton switch comes on.
They are of the push-push type: when you push a pushbutton switch (initial position), it moves in then out to a level above that of the unselected pushbutton switches. A white skirt on the pushbutton switch appears, the pushbutton switch comes on and the selected receiver is connected.
Rotate this pushbutton switch to adjust the reception level.
You can select several reception pushbutton switches simultaneously.
When you push the pushbutton switch again, it engages in its initial position: the receiver is disconnected.
The round reception pushbutton switches serve to select and adjust the audio levels.
When an audio channel is selected, the related reception pushbutton switch comes on.
They are of the push-push type: when you push a pushbutton switch (initial position), it moves in then out to a level above that of the unselected pushbutton switches. A white skirt on the pushbutton switch appears, the pushbutton switch comes on and the selected receiver is connected.
Rotate this pushbutton switch to adjust the reception level.
You can select several reception pushbutton switches simultaneously.
When you push the pushbutton switch again, it engages in its initial position: the receiver is disconnected.
F. Audio Control Panel-Functional description-Call indication
During a ground crew, Cabin Attendant or SELCAL call, a legend flashes amber under the green lines of the transmission pushbutton switch concerned.
This occurs whether the transmission pushbutton switch is selected or not:
During a ground crew, Cabin Attendant or SELCAL call, a legend flashes amber under the green lines of the transmission pushbutton switch concerned.
This occurs whether the transmission pushbutton switch is selected or not:
- CALL: VHF1-VHF2-VHF3-HF1-HF2-SATCOM 1-SATCOM 2 pushbutton switches (SELCAL call)
- MECH: INT pushbutton switch (ground crew call)
- ATT: CAB pushbutton switch (Cabin Attendant call).
To switch off the amber legends, push the RESET pushbutton switch, or push transmission pushbutton switch of related channel.
NOTE: The MECH and ATT legends which flash amber go off automatically. This occurs after 60 seconds of operation if the call is not cancelled by the RESET pushbutton switch. This automatic function can be inhibited by the AMU pin-program.
In the case of a SATCOM air-to-ground call, when the SATCOM transmission pushbutton switch located on the ACP is pushed , the AMU initiates a call. This causes the three green bars of the SATCOM transmission pushbutton switch to flash (flashing rate: 2 on/off cycles/second). Once the call is established, the three green bars stay on.
In the case of a SATCOM air-to-ground call, when the SATCOM transmission pushbutton switch located on the ACP is pushed , the AMU initiates a call. This causes the three green bars of the SATCOM transmission pushbutton switch to flash (flashing rate: 2 on/off cycles/second). Once the call is established, the three green bars stay on.
G. Audio Control Panel-Functional description-Voice selection
When you push the VOICE pushbutton switch, the ON legend comes on green. This indicates that a filter has been connected into the audio circuits of the ADF and the VOR navigation systems.
When you push this pushbutton switch again, the green ON legend goes off: the filter is no longer in service.
When you push the VOICE pushbutton switch, the ON legend comes on green. This indicates that a filter has been connected into the audio circuits of the ADF and the VOR navigation systems.
When you push this pushbutton switch again, the green ON legend goes off: the filter is no longer in service.
H. Audio Control Panel-Functional description-INT/RAD switch
This switch is used for the transmission function when the boomset or the oxygen mask is in service: it acts as the PTT switch for this equipment which unlike the hand microphone is not equipped with this type of control. This switch also sends a pulse to the transmitter selection logic of the AMU.
This switch is used for the transmission function when the boomset or the oxygen mask is in service: it acts as the PTT switch for this equipment which unlike the hand microphone is not equipped with this type of control. This switch also sends a pulse to the transmitter selection logic of the AMU.
(1) Center position
The radio transceiver receives no switchover information. It remains in reception function.
The radio transceiver receives no switchover information. It remains in reception function.
(2) RAD position
The radio transceiver receives (via the AMU) a switchover information.
It switches from reception to transmission function.
The radio transceiver receives (via the AMU) a switchover information.
It switches from reception to transmission function.
(3) INT position
This position enables direct use of the flight interphone.
There are two utilization procedures for the flight interphone.
This position enables direct use of the flight interphone.
There are two utilization procedures for the flight interphone.
- Normal mode
The user pushes the INT transmission pushbutton switch and uses it like an ordinary radio channel (he places and holds the INT/RAD switch in RAD position). - Direct mode
If user has selected a radio channel (VHF1, VHF2 etc.), he can, if he so wishes, use the flight interphone. To do this he does not have to release the transmission pushbutton switch. He shall simply place the INT/RAD switch in INT position.
NOTE: When this switch is set to RAD, it performs the same function as the radio switches located on the side-stick hand-grips. If conflicting orders are given by the side-stick switch (RAD position), and the corresponding ACP switch (INT position), the radio function takes priority over the interphone function.
I. Audio Control Panel-Functional description-Lighting
The ACP comprises 2 lighting circuits:
The ACP comprises 2 lighting circuits:
- The selection accepted (green) and the call (amber) indications can be adjusted by the DIM/BRIGHT circuit (6 V/4.5 V) (Ref. ATA 33-14-00-circuit LP).
- The integral lighting is adjusted by the pedestal integral lighting potentiometer (5 V-0 V) (Ref. ATA 33-13-00-circuit LF).
J. SELCAL Code Panel
(1) Function
The SELCAL code panel is used to program the SELCAL code assigned to the aircraft.
The SELCAL code panel is used to program the SELCAL code assigned to the aircraft.
(2) Description
This panel is a rectangular box in compliance with ARINC 714.
The face features:
This panel is a rectangular box in compliance with ARINC 714.
The face features:
- 4 thumbwheels for selection of a code made up of 4 letters from amongst the following:
A - B - C - D - E - F - G - H - J - K - L - M- N - P - Q - R - S. - A plexiglass cover over the thumbwheels which protects the displayed code. The operator can read the code through the cover.
- The rear is equipped with a round connector for connection to the aircraft electrical network.
K. Audio Management Unit
(1) Functions
The AMU is a computer which ensures the interface between the user and the various radio communication and radio navigation systems. The AMU manages receptions (volume control and selection) and transmissions (selections) independently for each user:
The AMU is a computer which ensures the interface between the user and the various radio communication and radio navigation systems. The AMU manages receptions (volume control and selection) and transmissions (selections) independently for each user:
- Captain
- First Officer
- 3rd Occupant.
Options: 4th and 5th Occupants.
The AMU also decodes coded calls on radio communication (SELCAL) channels, and ensures the BITE and flight interphone functions.
(2) Mechanical description
The AMU is in the form of a 4MCU size box in compliance with ARINC 600 Specification.
The AMU comprises:
The AMU is in the form of a 4MCU size box in compliance with ARINC 600 Specification.
The AMU comprises:
- Rear panel assembly
This includes the mother board and the rear panel - Audio-SELCAL assembly
This includes the audio board A (dedicated to CAPT and Avionics bay station) and the SELCAL board.
The two boards are attached together through spacers, and connected together through connectors. - Audio-BITE assembly This includes the audio board B (identical to audio board A and dedicated to F/O and 3rd OCCPNT) and the BITE board.
* On the AMU 4031LB, the functions related to 5th OCCPNT (additional cockpit station) are implemented on the BITE board. - Adaptation board
- Front panel assembly, which contains the cockpit amplifier board and the heatsink.
(a) A SELCAL BITE card
This card is located on one side of the AMU.
This card is located on one side of the AMU.
7. Operation
(1) General
The ACP is essentially a telecontrol panel.
The internal electronic circuit is structured around a microprocessor.
It constantly scans the status of the face controls and transforms them into logic data. It generates serial words from this logic data. These words telecontrol the associated audio card in the AMU after transmission of messages on an ARINC 429 bus line.
An ARINC 429 reception bus line enables the ACP to process the information from the AMU. These information are relevant to the different parameters to be displayed: detected calls, selected transmission channels, selection of the voice filter on. These parameters will be displayed once they have been taken into account by the AMU and acknowledged in return.
The system is therefore looped.
The ACP is essentially a telecontrol panel.
The internal electronic circuit is structured around a microprocessor.
It constantly scans the status of the face controls and transforms them into logic data. It generates serial words from this logic data. These words telecontrol the associated audio card in the AMU after transmission of messages on an ARINC 429 bus line.
An ARINC 429 reception bus line enables the ACP to process the information from the AMU. These information are relevant to the different parameters to be displayed: detected calls, selected transmission channels, selection of the voice filter on. These parameters will be displayed once they have been taken into account by the AMU and acknowledged in return.
The system is therefore looped.
(2) Operation
The data are managed and processed by a microcomputer.
There are five separate functions:
The data are managed and processed by a microcomputer.
There are five separate functions:
- reception volume control
- reception selection
- processing of the discrete commands:
. selection of transmission channel
. VOICE filter on/off command
. RAD/INT command - Parameter display management
- ARINC 429 interfaces.
(a) Reception volume control
This is achieved by the potentiometers accessible on the face. The position of each potentiometer is defined by an analog voltage on the slider. The potentiometers are supplied with a reference voltage.
An analog-digital converter makes the 8-bit words correspond to the slider voltages.
The slider voltages are read consecutively. Thus, the numerical codes which correspond to the angular positions of the potentiometers are obtained.
This is achieved by the potentiometers accessible on the face. The position of each potentiometer is defined by an analog voltage on the slider. The potentiometers are supplied with a reference voltage.
An analog-digital converter makes the 8-bit words correspond to the slider voltages.
The slider voltages are read consecutively. Thus, the numerical codes which correspond to the angular positions of the potentiometers are obtained.
(b) Reception selection
The potentiometer must be pushed to select a channel. The information is transmitted in the form of a word. This information is taken into account consecutively when the reception volume controls are scanned.
The potentiometer must be pushed to select a channel. The information is transmitted in the form of a word. This information is taken into account consecutively when the reception volume controls are scanned.
(c) Processing of discrete commands
The selection information of the RAD/INT command is constantly available on the switch. It can, therefore, be directly used by the microcomputer.
The transmission selection information (fugitive contacts) is memorized and is therefore available for use by the microcomputer.
The same applies to the VOICE filter control.
The selection information of the RAD/INT command is constantly available on the switch. It can, therefore, be directly used by the microcomputer.
The transmission selection information (fugitive contacts) is memorized and is therefore available for use by the microcomputer.
The same applies to the VOICE filter control.
(d) Parameter display management
The AMU return information is processed in order to make sure that the transmission is correct.
After this check, the display can be performed:
The AMU return information is processed in order to make sure that the transmission is correct.
After this check, the display can be performed:
- the light associated with the selected transmission channel comes on
- the light associated with the VOICE filter comes on
- the call lights come on.
B. SELCAL Code Panel
(1) Operation
In accordance with the BCD code, each of the thumbwheels opens the various circuits or connects the various circuits to the ground. This selects the different frequency filters assigned to the considered codes.
In accordance with the BCD code, each of the thumbwheels opens the various circuits or connects the various circuits to the ground. This selects the different frequency filters assigned to the considered codes.
- The Operating Diagram shows the control logic.
- When this circuit is connected to the ground or supplied with a voltage of +3.5 V a logic 0 is obtained. This corresponds to circuit operation.
- When the circuit is open or has a resistance greater than 50000 ohms a logic 1 is obtained. This corresponds to non operation of the circuit.
- The letter-frequency assignment table gives the letter-frequency assignments.
| ------------------------------------------------------------------------------- |
| ! DESIGNATION ! FREQUENCY ! BCD CODE ! |
| ------------------------------------------------------------------------------- |
| ! ! ! 8 4 2 1 ! |
| ! A ! 312.6 ! 0 0 0 1 ! |
| ! B ! 346.7 ! 0 0 1 0 ! |
| ! C ! 384.6 ! 0 0 1 1 ! |
| ! D ! 426.6 ! 0 1 0 0 ! |
| ! E ! 473.2 ! 0 1 0 1 ! |
| ! F ! 524.8 ! 0 1 1 0 ! |
| ! G ! 582.1 ! 0 1 1 1 ! |
| ! H ! 645.7 ! 1 0 0 0 ! |
| ! J ! 716.1 ! 1 0 0 1 ! |
| ! K ! 794.3 ! 1 0 1 0 ! |
| ! L ! 881 ! 1 0 1 1 ! |
| ! M ! 977.2 ! 1 1 0 0 ! |
| ! P ! 1083.9 ! 1 1 0 1 ! |
| ! Q ! 1202.3 ! 1 1 1 0 ! |
| ! R ! 1333.5 ! 1 1 1 1 ! |
| ! S ! 1479.1 ! 0 0 0 0 ! |
| ------------------------------------------------------------------------------- |
| The SELCAL code panel does not require an electrical power supply. |
(1) Transmission function
(a) General
The transmission function:
The transmission function:
- sets into service and supplies the various microphones used (boomset, hand microphone, oxygen mask microphone)
- selects the transmitter selected by the operator by means of the ACP.
(b) Transmission with various microphones
For transmission, each crew member can use either a hand microphone, a boomset or an oxygen mask. The analog signals of these three microphones are adapted and filtered on the adaptation board of the AMU, which also receives the hand microphone PTT and oxygen mask control discretes.
The microphone selection is done by a dedicated circuit according to the following logic:
At the transformer output, this signal is switched to the transmitter selected by the operator on the ACP, in accordance with information received from the DSP.
This discrete information is consolidated with both hardware and software processings, to avoid permanent transmission.
For transmission, each crew member can use either a hand microphone, a boomset or an oxygen mask. The analog signals of these three microphones are adapted and filtered on the adaptation board of the AMU, which also receives the hand microphone PTT and oxygen mask control discretes.
The microphone selection is done by a dedicated circuit according to the following logic:
| ----------------------------------------------------- |
| ! OXYGEN MASK CONTROL DISCRETE ! |
| !---------------------------------------------------! |
| ! 0 ! 1 ! |
| ---------------------!------------------------!--------------------------! |
| ! ! 0 ! Boomset signal valid ! Boomset and oxygen mask ! |
| ! HANDMIKE ! ! ! signals valid ! |
| ! PTT !-------!---------------------------------------------------! |
| ! ! 1 ! Handmike signal valid ! |
| -------------------------------------------------------------------------- |
NOTE: Input 6 microphone is valid when PTT6 is activated.
Ground Mech microphone is valid when air/ground discrete is set to GND.
The selected microphone signal is then sent to an output transformer. Ground Mech microphone is valid when air/ground discrete is set to GND.
At the transformer output, this signal is switched to the transmitter selected by the operator on the ACP, in accordance with information received from the DSP.
This discrete information is consolidated with both hardware and software processings, to avoid permanent transmission.
(c) Transmission on passenger address channel (PA)
Transmissions can be made on the passenger address channels in 2 ways:
Transmissions can be made on the passenger address channels in 2 ways:
- in normal configuration, use the handset installed aft of the center pedestal to make the PA announcements. This handset is part of the Cabin Intercommunication Data System (CIDS) (Ref. 23-73-00 Circuit RH).
- in RADIO configuration, use the PA pushbutton switch located on each ACP to make the passenger address announcements. This pushbutton switch is unstable, i.e. hold it pushed to make the announcements: this avoids unwanted transmissions. The electronic processing of this channel is identical to that of the other transmission channels.
The operation of this pushbutton switch can be made identical to that of the other transmission channels (stable operation): to achieve this, modify the AMU pin-program.
(2) Reception function
(a) General
The reception circuit selects and adjusts the volume on the reception channels. The operator selects and adjusts these channels on the ACP.
Each user of the audio management system has a separate associated reception-channel.
It ensures the various supplementary functions of the circuit:
The reception circuit selects and adjusts the volume on the reception channels. The operator selects and adjusts these channels on the ACP.
Each user of the audio management system has a separate associated reception-channel.
It ensures the various supplementary functions of the circuit:
- VOR/DME/ILS switching
- VOICE/IDENT function.
(b) Reception function
The audio signals from the various communication and navigation units are first connected to analog/digital converters, and then to the DSP located on the audio boards.
Dedicated inputs exist on the DSP for filtered signal (ADF and VOR).
The DSP is also connected to a control module which provides information computed from the ACP (potentiometers position, Voice filter selection) and from the FCU (DME coupling to VOR or LS). After digital processing inside the DSP, the resultant signal is converted into analog and sent to the output transformer.
The audio signals from the various communication and navigation units are first connected to analog/digital converters, and then to the DSP located on the audio boards.
Dedicated inputs exist on the DSP for filtered signal (ADF and VOR).
The DSP is also connected to a control module which provides information computed from the ACP (potentiometers position, Voice filter selection) and from the FCU (DME coupling to VOR or LS). After digital processing inside the DSP, the resultant signal is converted into analog and sent to the output transformer.
NOTE: A minimum VHF and HF reception level is ensured when the potentiometers on the ACP are set to minimum. The minimum reception level is deleted when the potentiometers are set to OFF.
Minimum reception level is -32 dB with reference to maximum level.
Minimum reception level is -32 dB with reference to maximum level.
(c) DME/VOR/LS switching
1 Function
In normal configuration, the DME reception is coupled with the VOR reception.
However, in certain landing system approach conditions, the DME used must be aurally identified. The DME reception must therefore be coupled with the MMR reception.
In normal configuration, the DME reception is coupled with the VOR reception.
However, in certain landing system approach conditions, the DME used must be aurally identified. The DME reception must therefore be coupled with the MMR reception.
2 Operation
The LS pushbutton switch is used for switching control (Ref. ATA 31 - DMC circuit (WT)).
Action on this command sends a ground to the AMU which couples the DME receptions to the MMR receptions.
The LS pushbutton switch is used for switching control (Ref. ATA 31 - DMC circuit (WT)).
Action on this command sends a ground to the AMU which couples the DME receptions to the MMR receptions.
(d) VOICE/ON function
1 Function
The VOR, ADF navigation ground stations transmit a morse code which is used to identify them. However, certain stations, in addition to their code, transmit recorded voice information. This information informs the crew of subjects such as: latest weather information, state or special information concerning terrains etc. (e.g.: ATIS station).
In order not to hinder the reception of this information, the VOICE/IDENT function greatly reduces the morse code reception. It is attenuated until it becomes practically inaudible while this information is being transmitted.
The VOR, ADF navigation ground stations transmit a morse code which is used to identify them. However, certain stations, in addition to their code, transmit recorded voice information. This information informs the crew of subjects such as: latest weather information, state or special information concerning terrains etc. (e.g.: ATIS station).
In order not to hinder the reception of this information, the VOICE/IDENT function greatly reduces the morse code reception. It is attenuated until it becomes practically inaudible while this information is being transmitted.
2 Operation
The transmission modulation frequency for ground station codes is 1020 Hz.
However, certain onboard equipment (COLLINS ADF) receive a 1020 Hz frequency-modulated signal and at same time transmit this signal at 1000 Hz to the audio system. The 1000 Hz signal is generated by their synthesizer (the aeronautical standards specify that the ADF ground stations must be modulated at a frequency of 1020 Hz plus or minus 50 Hz).
Furthermore, the DME reception is coupled to the VOR reception (in normal operation). Thus the DME marker identification-code is transmitted with a frequency modulation of 1350 Hz. The filtering circuit of the navigation channels therefore comprises an attenuation filter for the reception bands of the ADF and VOR systems.
This digital filter attenuates the 1000 and 1020 Hz frequencies by more than 32 dB.
Action on the VOICE pushbutton switch located on each ACP has the following effects:
The transmission modulation frequency for ground station codes is 1020 Hz.
However, certain onboard equipment (COLLINS ADF) receive a 1020 Hz frequency-modulated signal and at same time transmit this signal at 1000 Hz to the audio system. The 1000 Hz signal is generated by their synthesizer (the aeronautical standards specify that the ADF ground stations must be modulated at a frequency of 1020 Hz plus or minus 50 Hz).
Furthermore, the DME reception is coupled to the VOR reception (in normal operation). Thus the DME marker identification-code is transmitted with a frequency modulation of 1350 Hz. The filtering circuit of the navigation channels therefore comprises an attenuation filter for the reception bands of the ADF and VOR systems.
This digital filter attenuates the 1000 and 1020 Hz frequencies by more than 32 dB.
Action on the VOICE pushbutton switch located on each ACP has the following effects:
- Released position, VOICE/ON off
The filters are not used, the operator simultaneously receives the marker identification and the voice transmission. - Pressed in position, VOICE/ON on
The DSP directly processes the filtered signals. The 1000 - 1020 Hz frequencies are greatly attenuated, the DME identified is cut off (1350 Hz). Only the voice transmissions are audible.
NOTE: The audio outputs of the communication channel and the MMR, MKR navigation do not transit via digital filters.
(a) General
The emergency function is used in case of a failure on one audio board.
Pilots can activate it through a three-position selector switch located on the center pedestal.
The emergency function is used in case of a failure on one audio board.
Pilots can activate it through a three-position selector switch located on the center pedestal.
(b) Pilot emergency function
In case of a failure on the audio board A, the pilot's microphones and audio signals are switched through relays in parallel to the 3rd Occupant's microphone inputs and audio outputs.
The PTT commands from the pilot's microphones are active.
The pilot's ACP is no longer active.
In case of a failure on the audio board A, the pilot's microphones and audio signals are switched through relays in parallel to the 3rd Occupant's microphone inputs and audio outputs.
The PTT commands from the pilot's microphones are active.
The pilot's ACP is no longer active.
(c) Copilot
In case of a failure on the audio board B, the copilot's microphones and audio signals are switched through relays to the Avionics Bay microphone inputs and audio outputs, which are no longer active.
The PTT commands from the copilot's microphones are active.
The copilot's ACP is no longer active.
In addition, the 3rd Occupant's micro and audio signals are switched in parallel to the Avionics Bay micro and audio signals, and the 3rd ACP ARINC bus is switched to the Avionics Bay ACP ARINC input/output.
The Avionics Bay ACP ARINC line is cut.
In case of a failure on the audio board B, the copilot's microphones and audio signals are switched through relays to the Avionics Bay microphone inputs and audio outputs, which are no longer active.
The PTT commands from the copilot's microphones are active.
The copilot's ACP is no longer active.
In addition, the 3rd Occupant's micro and audio signals are switched in parallel to the Avionics Bay micro and audio signals, and the 3rd ACP ARINC bus is switched to the Avionics Bay ACP ARINC input/output.
The Avionics Bay ACP ARINC line is cut.
(a) Function
The Aeronautics Authorities for Civil Navigation request that the communications made onboard the aircraft are recorded on the CVR system (Cockpit Voice Recorder - Ref. ATA 23-71-RK).
To meet this requirement, the CVR is equipped with 4 recording tracks.
The Aeronautics Authorities for Civil Navigation request that the communications made onboard the aircraft are recorded on the CVR system (Cockpit Voice Recorder - Ref. ATA 23-71-RK).
To meet this requirement, the CVR is equipped with 4 recording tracks.
- 3 tracks for recording the Captain, First Officer, 3rd Occupant communications
- the 4th track is assigned to an area microphone installed in the cockpit. This microphone picks up the various noises made in the cockpit.
(b) FAA recording
All the communications heard by the Captain (or the First Officer or the 3rd Occupant) are recorded. This enables, at same time, to record all the communications sent out by these crew members. This is achieved by means of the side-tone controls on the various equipment.
A shunt is installed on the pin-programming terminal of the AMU to activate the FAA recording (TP - 9C).
All the communications heard by the Captain (or the First Officer or the 3rd Occupant) are recorded. This enables, at same time, to record all the communications sent out by these crew members. This is achieved by means of the side-tone controls on the various equipment.
A shunt is installed on the pin-programming terminal of the AMU to activate the FAA recording (TP - 9C).
(c) CAA recording
This configuration is named "Hot-mike".
The principle of CAA recording requires (in addition to the FAA recording principle) that the noises picked up by the boomset microphones be recorded even when these microphones are not active i.e. when the push-to-talk switches on the side-sticks or on the ACPs are not activated. This in order to reinforce the sounds picked-up by the area microphone.
This configuration is named "Hot-mike".
The principle of CAA recording requires (in addition to the FAA recording principle) that the noises picked up by the boomset microphones be recorded even when these microphones are not active i.e. when the push-to-talk switches on the side-sticks or on the ACPs are not activated. This in order to reinforce the sounds picked-up by the area microphone.
(d) DFDR/CVR Synchronization
The two recorders (CVR and DFDR) are synchronized:
The two recorders (CVR and DFDR) are synchronized:
- The DFDR receives the GMT signal from the FDIU,
- Also, the CVR receives the GMT signal from the FDIU. This signal is sent to the CVR via the AMU where it is mixed with the 3rd Occupant audio signals.
(a) Function
The flight interphone enables:
The flight interphone enables:
- telephone conversations between the various stations in the cockpit
- telephone conversations between the cockpit and the ground crew via the external power panel
- telephone conversations with a supplementary station (input 6).
(b) Operation
The flight interphone comprises the following functions:
The flight interphone comprises the following functions:
- microphone inputs
- amplification and summation
- audio output.
1 Microphone inputs
There are two types of microphone inputs:
There are two types of microphone inputs:
- normal inputs: inputs from the CAPT, F/O, 3rd OCCPNT , Avionics Bay (and optionally 4th OCCPNT)
- protected inputs: they comprise the mechanic input and the Reserve input (input 6).
2 Protected inputs
The mechanic input is disconnected from the interphone amplifier when the flight/ground information from the LGCIU is present (flight configuration).
The input 6 is disconnected from the interphone amplifier when the PTT input 6 is not activated.
The mechanic input is disconnected from the interphone amplifier when the flight/ground information from the LGCIU is present (flight configuration).
The input 6 is disconnected from the interphone amplifier when the PTT input 6 is not activated.
3 Architecture
The adaptation board perfoms the summing of all the modulation signals. As a security precaution, there are two independent summation circuits.
The output of the first summation circuit is transmitted to the "master" audio board (board A).
The output of the second summation circuit is transmitted to the "slave" audio board (board B).
The adaptation board perfoms the summing of all the modulation signals. As a security precaution, there are two independent summation circuits.
The output of the first summation circuit is transmitted to the "master" audio board (board A).
The output of the second summation circuit is transmitted to the "slave" audio board (board B).
NOTE: The ouputs of the first summation circuit is also transmitted to the MECH and Audio 6 outputs.
(6) Muting circuit
The conditions associated with appearance of the acoustic feedback are linked to the coupling of a microphone and a loud speaker. These conditions have two different aspects. One is linked to the microphone and loud speaker proximity (distance), the other to the electrical characteristics of the signals.
The coupling linked to microphone and loud speaker proximity cannot be avoided by the processing functions performed in the AMU.
In order to limit the accoustic feedback phenomene a circuit of muting is installed in the circuit amplifier.
The muting circuit does not affect the warning signals.
Two actions are defined in order to limit appearance of the acoustic feedback:
The conditions associated with appearance of the acoustic feedback are linked to the coupling of a microphone and a loud speaker. These conditions have two different aspects. One is linked to the microphone and loud speaker proximity (distance), the other to the electrical characteristics of the signals.
The coupling linked to microphone and loud speaker proximity cannot be avoided by the processing functions performed in the AMU.
In order to limit the accoustic feedback phenomene a circuit of muting is installed in the circuit amplifier.
The muting circuit does not affect the warning signals.
Two actions are defined in order to limit appearance of the acoustic feedback:
NOTE: Amplitude reduction of the loud speaker output signal
This attenuating circuit is controlled by the PTT switch of any of the radio communication microphones.
The attenuating circuit is an integral part of the loud speakers and is therefore described in 31-52-00 (WW).
This attenuating circuit is controlled by the PTT switch of any of the radio communication microphones.
The attenuating circuit is an integral part of the loud speakers and is therefore described in 31-52-00 (WW).
NOTE: Level reduction of the channel selected in transmit mode,
i.e. during activation of the transmit mode, in:
i.e. during activation of the transmit mode, in:
- a reduction of the bandwidth from 300 Hz - 6000 Hz to 300 Hz - 1800 Hz
- a - 6 dB reduction of general level with respect to the input level
- an additional - 3 dB reduction of level specific to the channel activated in transmit mode.
(7) SELCAL function - Mechanic call - Cabin attendant call
(a) Function
The SELCAL-CALL system of the audio management system gives:
The SELCAL-CALL system of the audio management system gives:
- A visual and aural indication of the calls from the ground stations (equipped with a coding device) or from the satellite (for satellite communications) which can be used by the aircraft installation. The calls are sent on the radio frequencies or on the satellite channels which link the aircraft to the ground. The communication channels used are : VHF1 - VHF2 - VHF3 - HF1 - HF2- SATCOM 1 and SATCOM 2.
NOTE: For SATCOM 1 and SATCOM 2 communications, the AMU detects a SELCAL call according to the status of discretes No. 1 and 2.
- A visual indication of the calls from the ground crew or from the Cabin Attendants.
NOTE: The ground crew call system is described in chapter 23-42-00:
Cockpit-to-ground crew call system (circuit WC).
The Cabin Attendant call system is part of chapter 23-73-00: Cabin Intercommunication Data System (circuit RH).
Cockpit-to-ground crew call system (circuit WC).
The Cabin Attendant call system is part of chapter 23-73-00: Cabin Intercommunication Data System (circuit RH).
(b) SELCAL
1 Ground system
As far as communications other than SATCOM communications are concerned the ground system transmits, via VHF or HF transmitters, a selective call code. This code comprises 2 consecutive pulses each containing a mixture of the 2 frequencies. This enables the calls to be differentiated.
The call comprises a single-code transmission without repeat.
For the satellite communications, the GES (Ground Earth Station),which is connected to the telecommunications international network, sends a digital message via the INMARSAT satellites to the aircraft.
As far as communications other than SATCOM communications are concerned the ground system transmits, via VHF or HF transmitters, a selective call code. This code comprises 2 consecutive pulses each containing a mixture of the 2 frequencies. This enables the calls to be differentiated.
The call comprises a single-code transmission without repeat.
For the satellite communications, the GES (Ground Earth Station),which is connected to the telecommunications international network, sends a digital message via the INMARSAT satellites to the aircraft.
a VHF and HF communications
The aircraft receivers detect and capture the call signals transmitted by the ground stations (VHF or HF). Once detected, the signals are sent to the AMU SELCAL board.
This SELCAL board is equipped with 5 inputs. These inputs correspond to the various communication facilities on the aircraft (VHF1 - VHF2 - VHF3 - HF1 - HF2).
The SELCAL function continuously monitors the digital data of the five radio communication channels. It analyzes the received signals to check if they comprise the frequencies relevant to aircraft code. The operator programs this code on the SELCAL code panel.
If the frequencies and aircraft code correspond, the warning system transmits an aural signal. The CALL legend on each ACP associated to the system which received the call (VHF1 - VHF2 - VHF3 - HF1 - HF2) comes on.
Push the RESET pushbutton switch located on each ACP, or push the related transmission pushbutton switch, to reset the aural and lighted call.
The aircraft receivers detect and capture the call signals transmitted by the ground stations (VHF or HF). Once detected, the signals are sent to the AMU SELCAL board.
This SELCAL board is equipped with 5 inputs. These inputs correspond to the various communication facilities on the aircraft (VHF1 - VHF2 - VHF3 - HF1 - HF2).
The SELCAL function continuously monitors the digital data of the five radio communication channels. It analyzes the received signals to check if they comprise the frequencies relevant to aircraft code. The operator programs this code on the SELCAL code panel.
If the frequencies and aircraft code correspond, the warning system transmits an aural signal. The CALL legend on each ACP associated to the system which received the call (VHF1 - VHF2 - VHF3 - HF1 - HF2) comes on.
Push the RESET pushbutton switch located on each ACP, or push the related transmission pushbutton switch, to reset the aural and lighted call.
b SATCOM communications
For the satellite communication, when the SELCAL decoder detects a call, as for VHF - HF the warning system transmits an aural signal and the CALL legend on each ACP associated to the channel which received the CALL (SATCOM 1 - SATCOM 2).
Push the RESET pushbutton switch located on each ACP, or push the related transmission pushbutton switch, to reset the aural and lighted call.
For the satellite communication, when the SELCAL decoder detects a call, as for VHF - HF the warning system transmits an aural signal and the CALL legend on each ACP associated to the channel which received the CALL (SATCOM 1 - SATCOM 2).
Push the RESET pushbutton switch located on each ACP, or push the related transmission pushbutton switch, to reset the aural and lighted call.
3 Associated peripheral assemblies
The SELCAL system is associated with:
The SELCAL system is associated with:
- the radio communication systems VHF1 - VHF2 - VHF3 - HF1 - HF2
- the FWC system.
4 Operation of the system
- Electrical characteristics
Number of inputs: 5
Input impedance: 10,000 ohms
Input signal level: 0.07 V to 3.2 V
(c) Operation
1 VHF and HF communications
The SELCAL signal issued by the various communication assemblies is applied, depending on its source, to one of the 5 input channels (VHF1, VHF2, VHF3, HF1, HF2).
The calculating unit:
Likewise, data is sent to the FWC system.
This enables audio indication of the call.
When an operator pushes the RESET pushbutton switch , or the related transmission pushbutton switch, on one of the ACPs, data is sent to the calculating unit via the associated audio board. This calculating unit re-initializes the system.
The SELCAL signal issued by the various communication assemblies is applied, depending on its source, to one of the 5 input channels (VHF1, VHF2, VHF3, HF1, HF2).
The calculating unit:
- recognizes if the code of the signals received corresponds to the code given by the SELCAL code panel
- interprets and manages the various information received from the input circuits: ground crew call, Cabin Attendant call, pin-program information, test request, etc.
- generates the various messages transmitted to the output circuits.
Likewise, data is sent to the FWC system.
This enables audio indication of the call.
When an operator pushes the RESET pushbutton switch , or the related transmission pushbutton switch, on one of the ACPs, data is sent to the calculating unit via the associated audio board. This calculating unit re-initializes the system.
2 SATCOM communications
As regards satellite communications, the SELCAL board manages the Captain and Avionics bay stations (First Officer and 3rd Occupant functions are implemented on the BITE board). The SELCAL board analyses and compares the status of discretes No. 1 and 2 (if a call is being made, discrete No. 2 is activated) and determines if it is a call. In this case, as for the other calls, the SELCAL board generates a digital message sent to the audio boards for the ACPs and then a data is sent to the FWC systems.
When an operator pushes the RESET pushbutton switch (or the related transmission pushbutton switch) on one of the ACPs, data is sent to the associated audio board. This data is transmitted to the calculating unit which re-initializes the system.
As regards satellite communications, the SELCAL board manages the Captain and Avionics bay stations (First Officer and 3rd Occupant functions are implemented on the BITE board). The SELCAL board analyses and compares the status of discretes No. 1 and 2 (if a call is being made, discrete No. 2 is activated) and determines if it is a call. In this case, as for the other calls, the SELCAL board generates a digital message sent to the audio boards for the ACPs and then a data is sent to the FWC systems.
When an operator pushes the RESET pushbutton switch (or the related transmission pushbutton switch) on one of the ACPs, data is sent to the associated audio board. This data is transmitted to the calculating unit which re-initializes the system.
(d) Ground crew and Cabin Attendant call system
- Operation of ground crew call
This circuit displays the call from the ground crew in the cockpit.
NOTE: Chapter ATA 23-42 (Cockpit-to-Ground Crew Call System - Circuit WC) gives the operation of the ground crew call circuit.
When an operator pushes the pushbutton switch 5WC (located on the external power panel 925VU) this sends ground information to the calculating unit.
The information is processed then a message is sent via the output stages to the audio boards and then to the ACPs.
This causes the MECH pushbutton switch to flash (coupled with the INT transmission pushbutton switch) for 60 seconds. After 60 seconds, or when an operator pushes the RESET pushbutton switch, like the SELCAL system, the circuit is re-initialized.
When an operator pushes the pushbutton switch 5WC (located on the external power panel 925VU) this sends ground information to the calculating unit.
The information is processed then a message is sent via the output stages to the audio boards and then to the ACPs.
This causes the MECH pushbutton switch to flash (coupled with the INT transmission pushbutton switch) for 60 seconds. After 60 seconds, or when an operator pushes the RESET pushbutton switch, like the SELCAL system, the circuit is re-initialized.
- Operation of Cabin Attendant call
NOTE: Chapter ATA 23-73 (Cabin Intercommunication Data System - Circuit RH) gives the operation of the call circuit.
When a call is made from the Cabin Attendant station, the CIDS generates ground information. This information is sent to the calculating unit.
The information is processed then sent to the ACPs through the audio boards. On the ACPs, this causes the ATT pushbutton switch to flash (coupled with the CAB pushbutton switch) for 60 seconds. After 60 seconds or when you push the RESET pushbutton switch, like the SELCAL system, the calculating unit re-initializes the circuit. It also sends information to the CIDS for re-initialization.
When a call is made from the Cabin Attendant station, the CIDS generates ground information. This information is sent to the calculating unit.
The information is processed then sent to the ACPs through the audio boards. On the ACPs, this causes the ATT pushbutton switch to flash (coupled with the CAB pushbutton switch) for 60 seconds. After 60 seconds or when you push the RESET pushbutton switch, like the SELCAL system, the calculating unit re-initializes the circuit. It also sends information to the CIDS for re-initialization.
NOTE: It is possible to inhibit the automatic function which causes the MECH and ATT flashing call pushbutton switches to stop. To do this, modify the AMU pin-program.
(a) Air-to-ground calls
Once SATCOM is selected on the ACP, discrete No. 1 (ground) is sent to the Satellite Data Unit (SDU) which sends a call request to the satellite. On the ACP, the green bars of corresponding transmission pushbutton switch flash.
When a communication between the satellite and the SDU is established, the SDU sends discrete No. 2 (ground) back to the AMU. On the ACP, the green bars of corresponding transmission pushbutton switch stay on.
Once SATCOM is selected on the ACP, discrete No. 1 (ground) is sent to the Satellite Data Unit (SDU) which sends a call request to the satellite. On the ACP, the green bars of corresponding transmission pushbutton switch flash.
When a communication between the satellite and the SDU is established, the SDU sends discrete No. 2 (ground) back to the AMU. On the ACP, the green bars of corresponding transmission pushbutton switch stay on.
(b) Ground-to-air calls
When a ground station wants to call the aircraft through satellite and initiates a call, the SDU sends discrete No. 2. On the ACP, CALL legend of transmission pushbutton switch flashes. Warning data is sent to the FWC, as for a SELCAL call.
On the ACP, when the RESET pushbutton switch is pushed or when applicable transmission channel is selected, SELCAL warning generated by the FWC is interrupted and the CALL legend on the ACP goes off.
When the pilot selects concerned SATCOM channel, the AMU connects discrete No. 1 to ground, green bars on SATCOM transmission pushbutton switch stay on and the call can go through.
When a ground station wants to call the aircraft through satellite and initiates a call, the SDU sends discrete No. 2. On the ACP, CALL legend of transmission pushbutton switch flashes. Warning data is sent to the FWC, as for a SELCAL call.
On the ACP, when the RESET pushbutton switch is pushed or when applicable transmission channel is selected, SELCAL warning generated by the FWC is interrupted and the CALL legend on the ACP goes off.
When the pilot selects concerned SATCOM channel, the AMU connects discrete No. 1 to ground, green bars on SATCOM transmission pushbutton switch stay on and the call can go through.
(c) Established communication
The AMU sends a ground on discrete No. 1 and the SDU sends a ground on discrete No. 2.
The AMU sends a ground on discrete No. 1 and the SDU sends a ground on discrete No. 2.
(d) Call termination
- Ground-originated call termination
Discrete No. 2 sent by the SDU changes status (open circuit). The green bars of SATCOM transmission pushbutton switch go off. - Air-originated call termination
When SATCOM channel is deselected, the green bars of SATCOM transmission pushbutton switch go off immediately but discrete No. 1 changes status (open circuit) only after a time delay of three seconds. During this time delay, if the flight crew wants to take up the call again, they must push the SATCOM transmission pushbutton switch (the green bars on this pushbutton switch will come on and stay on).
8. BITE Test
The Audio Management Unit (AMU) is equipped with a Type 1 BITE circuit.
The Audio Management Unit (AMU) is equipped with a Type 1 BITE circuit.
A. BITE Description
The two AUDIO boards, the SELCAL board, the BITE board and the ACPs are the elements monitored by the AMU BITE.
The two AUDIO boards, the SELCAL board, the BITE board and the ACPs are the elements monitored by the AMU BITE.
B. Function
(1) Maintenance
The main purpose of the AUDIO system BITE is to supply maintenance assistance. The integrated maintenance function has two levels :
The main purpose of the AUDIO system BITE is to supply maintenance assistance. The integrated maintenance function has two levels :
- a real time maintenance, which is active during the operation of the unit
- a ground maintenance, which brings into operation tests that cannot be performed during the flight.
The BITE board manages the dialogue with the CFDIU. It dates and stores in an EPROM memory all the faults detected in the system during the previous 63 flight legs.
The BITE board transmits to the CFDIU the data and information that follow : - functional status of the system (AMU and ACPs)
- results of the Built-in tests and of the CFDIU-requested tests
- unit ATA identifier code - part number and serial number of the unit
- part number of the ACPs
- pin programming, which is a constant data stored in the EPROM memory.
(2) Other functions
(a) Pin-program
The BITE board collects the information given by the pin-program.
It processes this information, then sends it to:
The pin-programm:
It is possible to modify the programming of the calculating unit. To do this, install specific shunts. This generates a message which (after it has been processed) is sent to the various ACPs, to the CMS or to the management microprocessor.
The BITE board collects the information given by the pin-program.
It processes this information, then sends it to:
- the two audio boards and then to the ACPs.
- the BITE circuit to enable this circuit to generate a data message which is sent to the CFDS.
The pin-programm:
- activates the function selection and CALL annunciators located on the front face of the ACP which correspond to the installed equipment (VHF3, HF1, HF2)
- activates the selection for ADF2 and MLS functions
- inhibits the automatic reset function after the Cabin Attendant and ground crew calls have operated for 60 seconds.
- enables change from CAA certification to FAA certification
- enables the PA transmission pushbutton switch located on each ACP to be given stable operation (i.e. same as the other transmission pushbutton switches).
- gives the informations necessary to the message sent to the CMC (Label 350 see chapter AMU - CFDIU interface).
It is possible to modify the programming of the calculating unit. To do this, install specific shunts. This generates a message which (after it has been processed) is sent to the various ACPs, to the CMS or to the management microprocessor.
(b) Additional cockpit occupant function (optional)
On AMU 4031LB, all the audio circuits and interfaces for the optional 4th Occupant (located in cockpit) are implemented on the BITE board :
On AMU 4031LB, all the audio circuits and interfaces for the optional 4th Occupant (located in cockpit) are implemented on the BITE board :
- power supply interface
- microphone supply interface
- selection and input of audio signals from the 4th Occupant microphones
- digital to analog conversion of reception signals
- amplification and impedance matching of audio output interface
- radio PTT selection interface
- discrete interface
- ARINC 429 interface with the 4th Occupant ACP
NOTE: For the other crew members, these circuits and interfaces are located on the audio boards and adaptation board.
(c) Satcom function
The BITE board provides the interface between the First Officer and 3rd Occupant ACPs and the Satcom transceivers (SDU).
For these occupants, the processing is similar to the Satcom function processing of the Captain and Avionics bay occupants (managed on the Selcal board).
The BITE board provides the interface between the First Officer and 3rd Occupant ACPs and the Satcom transceivers (SDU).
For these occupants, the processing is similar to the Satcom function processing of the Captain and Avionics bay occupants (managed on the Selcal board).
C. Operation
(1) Normal mode
The normal mode of operation consists in monitoring cyclically the status of the AMU boards and the status of the associated ACP, transmitting data to the CFDIU and, if any failure is detected, storing it in the fault memory.
The normal mode of operation consists in monitoring cyclically the status of the AMU boards and the status of the associated ACP, transmitting data to the CFDIU and, if any failure is detected, storing it in the fault memory.
(2) Menu mode
The menu mode of operation is only activated on the ground and it consists in a dialogue between the AMU and the operator through one of the three MCDUs. Flight/ground data is given by the CFDIU and when there is no data from a ground circuit (flight/ground discrete), it is given by the LGCIU.
For the Audio Integrating System (AIS), the menu mode consists of the following:
The menu mode of operation is only activated on the ground and it consists in a dialogue between the AMU and the operator through one of the three MCDUs. Flight/ground data is given by the CFDIU and when there is no data from a ground circuit (flight/ground discrete), it is given by the LGCIU.
For the Audio Integrating System (AIS), the menu mode consists of the following:
- a LAST LEG REPORT
- a PREVIOUS LEGS REPORT
- a LRU IDENTIFICATION
- a TROUBLE SHOOTING DATA
- a GROUND REPORT
- a TEST