DOC AIRBUS | AMM A320FSENSORS, POWER SUPPLY AND SWITCHING - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The aircraft is equipped with three Air Data/Inertial Reference Units (ADIRUs).
Each ADIRU receives data from four types of sensors:
The sensors, the probes, the ADMs and the ADIRUs are power supplied as follows:
In normal configuration, the Captain Primary Flight Display (PFD) and the Navigation Display (ND) show the data computed by the ADIRU 1.
The First Officer PFD and ND show the data computed by the ADIRU 2.
The data from the ADIRU 3 can be displayed by action on the AIR DATA selector switch or on the ATT HDG selector switch located on the SWITCHING panel.
These selector switches, which define a priority order for the ADIRUs, are also used by several other aircraft systems (Ref. Para. 4.F.).
** ON A/C NOT FOR ALL The aircraft is equipped with three Air Data/Inertial Reference Units (ADIRUs).
Each ADIRU receives data from four types of sensors:
- three pitot probes which provide total pressure data,
- six static probes which provide static pressure data,
- two Total Air Temperature (TAT) sensors which provide air temperature data,
- three Angle Of Attack (AOA) sensors which provide angle of attack data of the aircraft.
The sensors, the probes, the ADMs and the ADIRUs are power supplied as follows:
| ------------------------------------------- |
| ! EQUIPMENT ! 28VDC ! 115VAC ! 26VAC ! |
| ------------------------------------------- |
| ! ADIRU ! X ! X ! X ! |
| !----------------!-------!--------!-------! |
| ! AOA Sensor ! ! X ! X ! |
| !----------------!-------!--------!-------! |
| ! PITOT Probe ! ! X ! ! |
| !----------------!-------!--------!-------! |
| ! TAT Sensor ! ! X ! ! |
| !----------------!-------!--------!-------! |
| ! STATIC Probe ! X ! ! ! |
| !----------------!-------!--------!-------! |
| ! ADM !13.5VAC from ADIRU ! |
| ------------------------------------------- |
In normal configuration, the Captain Primary Flight Display (PFD) and the Navigation Display (ND) show the data computed by the ADIRU 1.
The First Officer PFD and ND show the data computed by the ADIRU 2.
The data from the ADIRU 3 can be displayed by action on the AIR DATA selector switch or on the ATT HDG selector switch located on the SWITCHING panel.
These selector switches, which define a priority order for the ADIRUs, are also used by several other aircraft systems (Ref. Para. 4.F.).
2. Component Location
The sensors, probes and ADMs are located on the aircraft as follows:
The different ADIRS switching devices are located on the aircraft as follows:
** ON A/C NOT FOR ALL The sensors, probes and ADMs are located on the aircraft as follows:
ADIRS - Probe and Sensor LocationThe different ADIRS switching devices are located on the aircraft as follows:
NOTE: The function of the switch (22FP) is described in DO 34-12-00 and DO 34-13-00.
| FIN | FUNCTIONAL DESIGNATION | PANEL | ZONE | ACCESS DOOR | ATA REF |
|---|---|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||||
| 3FP1 | SENSOR-ANGLE OF ATTACK, 1 | 231 | 34-11-19 | ||
| 3FP2 | SENSOR-ANGLE OF ATTACK, 2 | 232 | 34-11-19 | ||
| 3FP3 | SENSOR-ANGLE OF ATTACK, 3 | 127 | 34-11-19 | ||
| 7DA1 | PROBE-L STATIC, 1 | 127 | 34-11-16 | ||
| 7DA2 | PROBE-L STATIC, 2 | 127 | 34-11-16 | ||
| 7DA3 | PROBE-L STATIC, 3 | 121 | 34-11-16 | ||
| 8DA1 | PROBE-R STATIC, 1 | 128 | 34-11-16 | ||
| 8DA2 | PROBE-R STATIC, 2 | 128 | 34-11-16 | ||
| 8DA3 | PROBE-R STATIC, 3 | 122 | 34-11-16 | ||
| 9DA1 | PROBE-PITOT, 1 | 125 | 34-11-15 | ||
| 9DA2 | PROBE-PITOT, 2 | 126 | 34-11-15 | ||
| 9DA3 | PROBE-PITOT, 3 | 125 | 34-11-15 | ||
| 11FP1 | SENSOR-TAT, 1 | 121 | 34-11-18 | ||
| 11FP2 | SENSOR-TAT, 2 | 122 | 34-11-18 | ||
| 12FP | RELAY-ADIRS ON BAT/GROUND WARN | 103VU | 126 | 34-11-00 | |
| 13FP | SEL SW-ATT HDG | 8VU | 210 | 34-11-00 | |
| 14FP | RELAY-ADIRS 3 PWR SHEDDING | 103VU | 126 | 34-11-00 | |
| 15FP | SEL SW-AIR DATA | 8VU | 210 | 34-11-00 | |
| 16FP | RELAY-ADIRS 3 28VDC CONTROL | 103VU | 126 | 34-11-00 | |
| 17FP | RELAY-ADIRS 2 PWR SHEDDING | 103VU | 126 | 34-11-00 | |
| 19FP1 | ADM-L TOTAL PRESSURE | 125 | 34-11-17 | ||
| 19FP2 | ADM-R TOTAL PRESSURE | 126 | 34-11-17 | ||
| 19FP3 | ADM-STBY TOTAL PRESSURE | 125 | 34-11-17 | ||
| 19FP4 | ADM-R STATIC PRESSURE | 128 | 34-11-17 | ||
| 19FP5 | ADM-L STATIC PRESSURE | 127 | 34-11-17 | ||
| 19FP6 | ADM-R STATIC PRESSURE | 128 | 34-11-17 | ||
| 19FP7 | ADM-L STATIC PRESSURE | 127 | 34-11-17 | ||
| 19FP8 | ADM-STBY STATIC PRESSURE | 121 | 34-11-17 | ||
| 21FP1 | RELAY-AOA 1 TEST | 103VU | 126 | 34-11-00 | |
| 21FP2 | RELAY-AOA 2 TEST | 188VU | 128 | 34-11-00 | |
| 21FP3 | RELAY-AOA 3 TEST | 187VU | 127 | 34-11-00 | |
| 22FP | SW-L/G DOWN VMO/MMO SELECTION | 188VU | 128 | 34-11-00 | |
| 23FP | RELAY-ADIRS LGCIU GND POS | 103VU | 126 | 34-11-00 | |
3. Power Supply
A. General
The ADIRU is normally supplied with 115 VAC, 400 Hz power for the ADR and IR functions. However, its AOA resolver converter module is supplied with 26 VAC, 400 Hz.
The 28 VDC back-up generation is provided by batteries and is automatically used when the main power exceeds its normal limits.
At the beginning of each power cycle, the ADIRU switches from the main to the back-up power to test the electrical generation.
The table below gives the power consumption of each unit of the ADIRS:
The ADIRU is normally supplied with 115 VAC, 400 Hz power for the ADR and IR functions. However, its AOA resolver converter module is supplied with 26 VAC, 400 Hz.
The 28 VDC back-up generation is provided by batteries and is automatically used when the main power exceeds its normal limits.
At the beginning of each power cycle, the ADIRU switches from the main to the back-up power to test the electrical generation.
The table below gives the power consumption of each unit of the ADIRS:
| ------------------------------------------------------------------ |
| ! EQUIPMENT ! 28VDC ! 115VAC ! 26VAC ! |
| ! !-------------------!-------------------! ! |
| ! ! Typical ! Maximum ! Typical ! Maximum ! ! |
| ------------------------------------------------------------------ |
| ! ADIRU ! 48 W ! 61 W ! 79 VA ! 98 VA ! 1 VA ! |
| !----------------!---------!---------!---------!---------!-------! |
| ! AOA Sensor ! ! ! 250 VA ! 320 VA !3.5 VA ! |
| !----------------!---------!---------!---------!---------!-------! |
| ! PITOT Probe ! ! ! 281 VA ! 360 VA ! ! |
| !----------------!---------!---------!---------!---------!-------! |
| ! TAT Sensor ! ! ! 200 VA ! 350 VA ! ! |
| !----------------!---------!---------!---------!---------!-------! |
| ! STATIC Probe ! ! 2X75 W ! ! ! ! |
| !----------------!---------!---------!---------!---------!-------! |
| ! PHC ! ! 14 W ! ! ! ! |
| ------------------------------------------------------------------ |
(1) The ADIRU power consumption includes the supply of three ADMs.
With the ON BAT annunciator, add 5 W.
With the IR FAULT annunciator at I = 250 mA, add 10.5 W.
Other annunciators are open/ground discretes and so they are energized by a power which is different from the ADIRU power.
When the ADIRU is in the OFF mode, all the circuitry in the ADIRU is de-energized except for any logic associated with the power-off function. The current does not exceed 10 mA DC.
Each ADIRU supplies power for the ADM of its side (CAPT, F/O, STBY).
The ADIRU also supplies the CDU with a 28 VDC signal. The consumption of the CDU is 6 W (typical) and 10 W (maximum).
With the ON BAT annunciator, add 5 W.
With the IR FAULT annunciator at I = 250 mA, add 10.5 W.
Other annunciators are open/ground discretes and so they are energized by a power which is different from the ADIRU power.
When the ADIRU is in the OFF mode, all the circuitry in the ADIRU is de-energized except for any logic associated with the power-off function. The current does not exceed 10 mA DC.
Each ADIRU supplies power for the ADM of its side (CAPT, F/O, STBY).
The ADIRU also supplies the CDU with a 28 VDC signal. The consumption of the CDU is 6 W (typical) and 10 W (maximum).
B. ADIRS Power Supply Distribution in Normal Configuration
(1) Captain side
The ADIRU 1 is supplied with 115 VAC by the 115 VAC SHED ESS BUS 801XP-A. The back-up 28 VDC is provided by the 28 VDC HOT BUS 702PP. The resolvers of the AOA sensor 1 and the AOA resolver converter module of the ADIRU 1 are supplied with 26 VAC by the 26 VAC ESS BUS 431XP-A.
The sensors and probes (static, TAT, pitot, AOA) are supplied for heating through the PHC 1:
The ADIRU 1 is supplied with 115 VAC by the 115 VAC SHED ESS BUS 801XP-A. The back-up 28 VDC is provided by the 28 VDC HOT BUS 702PP. The resolvers of the AOA sensor 1 and the AOA resolver converter module of the ADIRU 1 are supplied with 26 VAC by the 26 VAC ESS BUS 431XP-A.
The sensors and probes (static, TAT, pitot, AOA) are supplied for heating through the PHC 1:
- the heating element of the AOA sensor 1 receives 115 VAC from the 115 VAC SHED ESS BUS 801XP,
- the heating element of the TAT sensor 1 receives 115 VAC from the 115 VAC BUS 1 101XP-A,
- the heating element of the L and R static probes 1 receives 28 VDC from the 28 VDC BUS 1 101PP,
- the heating element of the pitot probe 1 receives 115 VAC from the 115VAC ESS BUS 401XP.
NOTE: The ADIRS/PHC Interface figure is a principle diagram and does not show the interface between the PHC and the sensors.
(Ref. 30-31-00 for more details on probe ice protection).
(Ref. 30-31-00 for more details on probe ice protection).
(2) First Officer side
The ADIRU 2 is supplied with 115 VAC by the 115 VAC BUS 2 204XP. The back-up 28 VDC is provided by the 28 VDC HOT BUS 702PP. The resolvers of the AOA sensor 2 and the AOA resolver converter module of the ADIRU 2 are supplied with 26 VAC by the 26 VAC BUS 2 231XP-A.
The sensors and probes are supplied for heating through the PHC 2:
The ADIRU 2 is supplied with 115 VAC by the 115 VAC BUS 2 204XP. The back-up 28 VDC is provided by the 28 VDC HOT BUS 702PP. The resolvers of the AOA sensor 2 and the AOA resolver converter module of the ADIRU 2 are supplied with 26 VAC by the 26 VAC BUS 2 231XP-A.
The sensors and probes are supplied for heating through the PHC 2:
- the heating element of the AOA sensor 2 receives 115 VAC from the 115 VAC BUS 2 202XP-B,
- the heating element of the TAT sensor 2 receives 115 VAC from the 115 VAC BUS 2 202XP-C,
- the heating element of the L and R static probes 2 receives 28 VDC from the 28 VDC BUS 2 206PP,
- the heating element of the pitot probe 2 receives 115 VAC from the 115 VAC BUS 2 202XP-B.
(3) Standby side
The ADIRU 3 is supplied with 115 VAC by the 115 VAC BUS 1 101XP-C. The back-up 28 VDC is provided by the 28 VDC HOT BUS 701PP. The resolvers of the AOA sensor 3 and the AOA resolver converter module of the ADIRU 3 are supplied with 26 VAC by the 26 VAC BUS 1 131XP-A.
The sensors and probes are supplied for heating through the PHC 3:
The ADIRU 3 is supplied with 115 VAC by the 115 VAC BUS 1 101XP-C. The back-up 28 VDC is provided by the 28 VDC HOT BUS 701PP. The resolvers of the AOA sensor 3 and the AOA resolver converter module of the ADIRU 3 are supplied with 26 VAC by the 26 VAC BUS 1 131XP-A.
The sensors and probes are supplied for heating through the PHC 3:
- the heating element of the AOA sensor 3 receives 115 VAC from the 115 VAC BUS 1 103XP,
- the heating element of the L and R static probes 3 receives 28 VDC from the 28 VDC BUS 1 103PP
- the heating element of the pitot probe 3 receives 115 VAC from the 115 VAC BUS 1 103XP.
C. ADIRS Power Supply Distribution after Loss of Main Electrical Generation
(1) Loss of the main generation and ATT HDG selector switch in NORM position
(a) Captain side
The ADIRU 1 is supplied as in normal configuration.
(Ref. Para B.(1)).
The ADIRU 1 is supplied as in normal configuration.
(Ref. Para B.(1)).
(b) First Officer side
The ADIRU 2 is no more supplied with 115 VAC and 26 VAC. When the 26 VAC is lost, the ADR detects a fault and flags the output parameters. The ADIRU is still powered with 28 VDC from the 28 VDC HOT BUS 702PP but the Time Delay Opening (TDO) relay 17FP will cut this supply after 5 minutes in emergency configuration.
The ADR 2 function is lost immediately.
The IR 2 function is lost after 5 minutes.
The ADIRU 2 is no more supplied with 115 VAC and 26 VAC. When the 26 VAC is lost, the ADR detects a fault and flags the output parameters. The ADIRU is still powered with 28 VDC from the 28 VDC HOT BUS 702PP but the Time Delay Opening (TDO) relay 17FP will cut this supply after 5 minutes in emergency configuration.
The ADR 2 function is lost immediately.
The IR 2 function is lost after 5 minutes.
(c) Standby side
The ADIRU 3 is no more supplied with 115 VAC and 26 VAC.
When the 26 VAC is lost, the ADR detects a fault and flags the output parameters. The ADIRU is still powered with 28 VDC from the 28 VDC HOT BUS 701PP but the Time Delay Opening (TDO) relay 14FP will cut this supply after 5 minutes in emergency configuration.
The ADR3 function is lost immediately.
The IR 3 function is lost after 5 minutes.
The ADIRU 3 is no more supplied with 115 VAC and 26 VAC.
When the 26 VAC is lost, the ADR detects a fault and flags the output parameters. The ADIRU is still powered with 28 VDC from the 28 VDC HOT BUS 701PP but the Time Delay Opening (TDO) relay 14FP will cut this supply after 5 minutes in emergency configuration.
The ADR3 function is lost immediately.
The IR 3 function is lost after 5 minutes.
(2) Loss of the main generation and ATT HDG selector switch in CAPT/3 position
The CAPT/3 position of the ATT HDG selector switch corresponds to the selection of the IR 3 in place of the IR 1. The power supply distribution must then be modified to keep the IR 3 in emergency configuration.
The CAPT/3 position of the ATT HDG selector switch corresponds to the selection of the IR 3 in place of the IR 1. The power supply distribution must then be modified to keep the IR 3 in emergency configuration.
(a) Captain side
The ADIRU 1 is supplied as in normal configuration
(Ref. Para. B.(1)).
The ADIRU 1 is supplied as in normal configuration
(Ref. Para. B.(1)).
(b) First Officer side
ADIRU 2 supply: Ref. Para. (1)(b).
ADIRU 2 supply: Ref. Para. (1)(b).
(c) Standby side
The ADIRU 3 is no more supplied with 115 VAC. The ADIRU 3 is still powered with 28 VDC from the 28 VDC HOT BUS 701PP.
The ADR 3 function is lost immediately.
The IR 3 function is available.
The ADIRU 3 is no more supplied with 115 VAC. The ADIRU 3 is still powered with 28 VDC from the 28 VDC HOT BUS 701PP.
The ADR 3 function is lost immediately.
The IR 3 function is available.
D. Circuit Breakers
The system is supplied through these circuit breakers:
The system is supplied through these circuit breakers:
| ----------------------------------------------------------------------------- |
| FIN PANEL/ DESIGNATION BUS ATA. REF. AMM |
| LOCATION P. BLOCK 001 |
| ----------------------------------------------------------------------------- |
| 4FP1 49VU NAV AND PROBES/ADIRU1/115VAC 801XP-A 34-11-00 |
| 4FP2 121VU ADIRS/ADIRU/2/115VAC 204XP-C 34-11-00 |
| 4FP3 121VU ADIRS/ADIRU/3/115VAC 101XP-C 34-11-00 |
| 5FP1 49VU NAV AND PROBES/ADIRU1 & 431XP-A 34-11-00 |
| AOA/26VAC |
| 5FP2 121VU ADIRS/ADIRU/2/26VAC AND AOA 231XP-A 34-11-00 |
| 5FP3 121VU ADIRS/ADIRU/3/26VAC AND AOA 131XP-A 34-11-00 |
| 6FP1 105VU ADIRS/ADIRU/1/28VDC 702PP 34-11-00 |
| 6FP2 121VU ADIRS/ADIRU/2/28VDC 702PP 34-11-00 |
| 6FP3 121VU ADIRS/ADIRU/3/28VDC 701PP 34-11-00 |
| 8FP 49VU NAV AND PROBES/ADIRU 3/ 401PP 34-11-00 |
| SWTG/SPLY |
| 9FP 121VU ADIRS/ADIRU/3 SWTG/SPLY 301PP 34-11-00 |
| 10FP 121VU ADIRS/ADIRU/2 PWR/SHED 206PP 34-11-00 |
| 1DA1 122VU ANTI ICE/PROBES/1/TAT 101XP-A 30-31-00 |
| 1DA2 122VU ANTI ICE/PROBES/2/TAT 202XP-C 30-31-00 |
| 2DA1 49VU ANTI ICE/PROBES/PHC/1 401PP 30-31-00 |
| 2DA2 122VU ANTI ICE/PROBES/2/PHC 206PP 30-31-00 |
| 2DA3 122VU ANTI ICE/PROBES/PHC/3 101PP 30-31-00 |
| 3DA1 49VU ANTI ICE/PROBES/PITOT/1 401XP-B 30-31-00 |
| 3DA2 122VU ANTI ICE/PROBES/2/PITOT 202XP-B 30-31-00 |
| 3DA3 122VU ANTI ICE/PROBES/3/PITOT 103XP-C 30-31-00 |
| 4DA1 49VU ANTI ICE/PROBES/1/AOA 801XP-C 30-31-00 |
| 4DA2 122VU ANTI ICE/PROBES/2/AOA 202XP-B 30-31-00 |
| 4DA3 122VU ANTI ICE/PROBES/3/AOA 103XP-C 30-31-00 |
| 5DA1 122VU ANTI ICE/PROBES/1/STATIC 101PP 30-31-00 |
| 5DA2 122VU ANTI ICE/PROBES/2/STATIC 206PP 30-31-00 |
| 5DA3 122VU ANTI ICE/PROBES/3/STATIC 103PP 34-11-00 |
4. Component Description
A. Static Probes FIN: 7-DA-1 FIN: 7-DA-2 FIN: 7-DA-3 FIN: 8-DA-1 FIN: 8-DA-2 FIN: 8-DA-3
Each of the three systems (CAPT (1), F/O (2), STBY (3)) comprises two static probes which are linked to each ADR portion of the ADIRUs through five ADMs.
The probe is protected from icing with a 28 VDC heater circuit.
The static probes linked to the ADIRU 1 and ADIRU 2 are set at 48.64 deg. below the fuselage datum line (Z=0).
The static probes linked to ADIRU 3 are set at 29.5 deg. below the fuselage datum line.
The pitot probe comprises a three-pin connector defined as follows:
Each of the three systems (CAPT (1), F/O (2), STBY (3)) comprises two static probes which are linked to each ADR portion of the ADIRUs through five ADMs.
The probe is protected from icing with a 28 VDC heater circuit.
The static probes linked to the ADIRU 1 and ADIRU 2 are set at 48.64 deg. below the fuselage datum line (Z=0).
The static probes linked to ADIRU 3 are set at 29.5 deg. below the fuselage datum line.
The pitot probe comprises a three-pin connector defined as follows:
B. Pitot Probes FIN: 9-DA-1 FIN: 9-DA-2 FIN: 9-DA-3
Each system comprises one pitot probe (CAPT (1), F/O (2), STBY (3)) which is linked to each ADR portion of the ADIRUs through one ADM.
The probe is protected from icing with a 115 VAC - 400 Hz heater circuit.
The pitot probes 1 and 2 are set at 40.08 deg. below the fuselage datum line (Z=0).
The pitot probe 3 is set at 59.56 deg. below the fuselage datum line (Z=0).
Each system comprises one pitot probe (CAPT (1), F/O (2), STBY (3)) which is linked to each ADR portion of the ADIRUs through one ADM.
The probe is protected from icing with a 115 VAC - 400 Hz heater circuit.
The pitot probes 1 and 2 are set at 40.08 deg. below the fuselage datum line (Z=0).
The pitot probe 3 is set at 59.56 deg. below the fuselage datum line (Z=0).
C. Air Data Modules (ADM) FIN: 19-FP-1 FIN: 19-FP-2 FIN: 19-FP-3 FIN: 19-FP-4 FIN: 19-FP-5 FIN: 19-FP-6 FIN: 19-FP-7 FIN: 19-FP-8
The term Air Data Module (ADM) refers to any remotely-located LRU which senses pressure information and transmits it to the ADIRU in ARINC 429 format.
The ADMs are remotely mounted near and above the level of the pitot and static probes, this in order to make the ADM pneumatic plumbing self draining when the aircraft is stationary on the ground.
The term Air Data Module (ADM) refers to any remotely-located LRU which senses pressure information and transmits it to the ADIRU in ARINC 429 format.
The ADMs are remotely mounted near and above the level of the pitot and static probes, this in order to make the ADM pneumatic plumbing self draining when the aircraft is stationary on the ground.
(1) Internal description
The ADM comprises the following components:
The ADM comprises the following components:
(a) Transducer board
This device provides two signals (Pressure Time Pulse (PTP) and Temperature Time Pulse (TTP)) used by the processor board.
This device provides two signals (Pressure Time Pulse (PTP) and Temperature Time Pulse (TTP)) used by the processor board.
(b) Processor board
The microcomputer comprises the following circuits:
The microcomputer comprises the following circuits:
- a micro-controller 80C31,
- two memories: ROM (storage of software program) and RAM (temporary storage of data),
- a Non Volatile Memory (NVM) (Storage of transducer modeling coefficients and failure information),
- a RS-232C Serial Digital Input/Output (used for bench test and calibration purposes),
- an ARINC 429 transmitter.
(c) EMI/lightning board
This board comprises the following devices:
This board comprises the following devices:
- power supply: the ADM is supplied by the associated ADIRU with +/- 13.5 VAC. The power consumption is less than 200 mA on the +13.5 VDC input and less than 50 mA on the -13.5 VDC input.
- EMI filters
- lightning protection
- filtering of input discretes.
(2) Modes of operation
The ADM has three modes of operation:
The ADM has three modes of operation:
- initialization
- normal operation
- Memory Access/Calibration (MA/C).
(a) Initialization mode
The ADM automatically enters the initialization mode immediately after power is applied to the device or after a Watchdog Timer is activated due to an ADM failure.
The ADM performs several tasks while in the initialization mode:
The initialization mode is completed within 900 ms (maximum) after valid power is applied to the ADM. Upon completion of the initialization mode, the ADM automatically enters the normal operation mode.
The ADM automatically enters the initialization mode immediately after power is applied to the device or after a Watchdog Timer is activated due to an ADM failure.
The ADM performs several tasks while in the initialization mode:
- initializes software variables and hardware interfaces,
- performs various self-monitoring tests to determine if the ADM operates properly,
- reads the fixed Program Pin discretes.
The initialization mode is completed within 900 ms (maximum) after valid power is applied to the ADM. Upon completion of the initialization mode, the ADM automatically enters the normal operation mode.
(b) Normal operation mode
The ADM enters the normal operation mode after the completion of the initialization mode. It remains in the normal operation mode until either power is removed from the ADM, or an internal failure activates the Watchdog Timer, or an internal BITE detects an unsafe condition, at which time a failure warning is annunciated or ARINC 429 transmissions cease.
The ADM performs the following functions in the normal operation mode:
The ADM enters the normal operation mode after the completion of the initialization mode. It remains in the normal operation mode until either power is removed from the ADM, or an internal failure activates the Watchdog Timer, or an internal BITE detects an unsafe condition, at which time a failure warning is annunciated or ARINC 429 transmissions cease.
The ADM performs the following functions in the normal operation mode:
- measures the pressure and temperature outputs from the transducer,
- uses filtering or averaging techniques consistent with the noise, resolution, and dynamic frequency response requirements
- computes the Applied Pressure based upon the pressure and temperature signals,
- filters the Computed Pressure,
- formats the ARINC 429 word to be transmitted,
- transmits the ARINC 429 Computed Pressure word,
- formats and transmits two ADM discrete words (labels 270, 271),
- reads and debounces the MA/C discretes,
- performs the BITE functions,
- formats and transmits ADM software and equipment I.D. words (labels 040,377).
(c) Memory access/calibration mode
The Memory access/calibration (MA/C) mode is used for purposes of transducer calibration and fault analysis. The MA/C mode requires external test equipment which interfaces to the ADM via a RS-232C bus. This mode can be considered as an auxiliary mode which is accessible in a repair shop environment only.
The Memory access/calibration (MA/C) mode is used for purposes of transducer calibration and fault analysis. The MA/C mode requires external test equipment which interfaces to the ADM via a RS-232C bus. This mode can be considered as an auxiliary mode which is accessible in a repair shop environment only.
(3) Discrete inputs
Table 1 gives the identification of the ADM discrete inputs:
Table 1 gives the identification of the ADM discrete inputs:
| -------------------------------------------- |
| ! ADM Pin ! Identification ! |
| -------------------------------------------- |
| ! K ! SDI 1 (LSB) (2) ! |
| ! L ! SDI 2 (MSB) (2) ! |
| ! M ! Configuration code 1 (3) ! |
| ! N ! Configuration code 2 (3) ! |
| ! P ! Parity (1) ! |
| ! a ! Memory Access/Calibration 1 ! |
| ! b ! NVM reset discrete ! |
| ! c ! Memory Access/Calibration 2 ! |
| -------------------------------------------- |
| Table 1 = Discrete Inputs |
NOTE: (1) An odd number of pins K, L, M, N and P must be grounded to signify a valid installation. After the desired Source Data Identifier (SDI) and the configuration pins have been selected, the parity pin P must be selectively left open or grounded to ensure that an odd number of pins K through P inclusive have been grounded.
NOTE: (2) Program pins used for identification of the installation position on the aircraft and the corresponding SDI code to be transmitted. The code definition is provided in table 2.
NOTE: (3) The ADM transmits the measured pressure with a label depending on the configuration code input discretes. The configuration code definition is provided in table 3.
| ------------------------------------------------------------------------ |
| !Input discrete SDI output !Input discrete SDI output !Installation! |
| ! pin L Bit 10 state! pin K Bit 09 state! ! |
| !----------------------------------------------------------------------! |
| ! open 0 ! open 0 ! Invalid ! |
| ! open 0 ! ground 1 ! 1 ! |
| ! ground 1 ! open 0 ! 2 ! |
| ! ground 1 ! ground 1 ! 3 ! |
| ------------------------------------------------------------------------ |
| Table 2 = SDI Code |
| --------------------------------------------------------------------- |
| ! Installation function ! Config. code 2 ! Config. code 1 ! Label ! |
| ! ! Pin N ! Pin M ! ! |
| !-------------------------------------------------------------------! |
| ! Total pressure ! open ! open ! 242 ! |
| ! Left static pressure ! open ! ground ! 176 ! |
| ! Right static pressure ! ground ! open ! 177 ! |
| ! Averaged static ! ground ! ground ! 245 ! |
| ! pressure (uncorrected)! ! ! ! |
| --------------------------------------------------------------------- |
| Table 3 = Configuration Code |
(4) Output bus
All data are transmitted via a single ARINC 429 low-speed serial digital output bus. The outputs from the ADM are a single pressure word having an installation selectable label, two discrete data words and two identification words.
The following table gives:
All data are transmitted via a single ARINC 429 low-speed serial digital output bus. The outputs from the ADM are a single pressure word having an installation selectable label, two discrete data words and two identification words.
The following table gives:
- EQ.SYS.LAB.SDI: (SDAC, FWC, DMC...) output label for which the parameter is available
- PARAMETER DEFINITION: parameter name
- WORD RANGE/OPER RANGE/RESOLUTION ACCURACY: measurement range. Maximum value transmitted. When the digital value changes, the change step is equal to the accuracy
- UNIT: unit in which the digital value is transmitted
- SIG BIT: indicates whether a sign bit is available
- BITS: number of bits used by the parameter in the label
- XMSN/INTV: output transmission interval. The refresh rate is given in milliseconds
- CODE :
BNR: binary data word
BCD: binary coded decimal data word
ISO: data word coded in ISO5 code
DIS: discrete data word
HEX: hexadecimal coded
HYB: mixed code parameters are given in the table 4 below: - ALPHA CODE: indicates the parameter mnemonic code
- SOURCE ORIGIN: parameter source computer or system.
| ------------------------------------------------------------------------------- |
| | PARAMETER LIST PARAMETER CHARACTERISTICS (NUMERIC) | |
| ------------------------------------------------------------------------------- |
| |EQ.SYS.LAB.SDI|PARAMETER | WORD RANGE |UNIT|SIG |BITS|XMSN|CODE|ALPHA|SOURCE | |
| | |DEFINITION| OPER RANGE | |BIT | |INTV| |CODE |ORIGIN | |
| | |(*=REMARK)| RESOLUTION | | | | | | |BUS No.| |
| | |(X=NOTE) | ACCURACY | | | | | | |ATA REF| |
| | | | | | | | | | |CONV | |
| ------------------------------------------------------------------------------- |
| ! 242 !TOTAL !100-1400 !hPa ! ! 18 !29- !BNR ! ! ! |
| ! !PRESSURE !+/- 0.25 ! ! ! !31 ! ! ! ! |
| !--------------!----------!------------!----!----!----!----!----!-----!-------! |
| ! 176 !LEFT STAT !100-1100 !hPa ! ! 18 !29- !BNR ! ! ! |
| ! !PRESSURE !+/- 0.25 ! ! ! !31 ! ! ! ! |
| !--------------!----------!------------!----!----!----!----!----!-----!-------! |
| ! 177 !RIGHT STAT!100-1100 !hPa ! ! 18 !29- !BNR ! ! ! |
| ! !PRESSURE !+/- 0.25 ! ! ! !31 ! ! ! ! |
| !--------------!----------!------------!----!----!----!----!----!-----!-------! |
| ! 245 !AVERAGED !100-1100 !hPa ! ! 18 !29- !BNR ! ! ! |
| ! !STATIC !+/- 0.25 ! ! ! !31 ! ! ! ! |
| ! !PRESSURE ! ! ! ! ! ! ! ! ! |
| ! !(UNCORRTD)! ! ! ! ! ! ! ! ! |
| !--------------!----------!------------!----!----!----!----!----!-----!-------! |
| ! 270 !DISCRETE !Table 5 ! ! ! !460-!BCD ! ! ! |
| ! !WORD 1 ! ! ! ! !500 ! ! ! ! |
| !--------------!----------!------------!----!----!----!----!----!-----!-------! |
| ! 271 !DISCRETE !Table 6 ! ! ! !460-!BCD ! ! ! |
| ! !WORD 2 ! ! ! ! !500 ! ! ! ! |
| !--------------!----------!------------!----!----!----!----!----!-----!-------! |
| ! 377 !EQUIPMENT !Table 7 ! ! ! !460-!BCD ! ! ! |
| ! !IDENT ! ! ! ! !500 ! ! ! ! |
| !--------------!----------!------------!----!----!----!----!----!-----!-------! |
| ! 040 !SOFTWARE !Table 8 ! ! ! !460-!BCD ! ! ! |
| ! !IDENT ! ! ! ! !500 ! ! ! ! |
| ------------------------------------------------------------------------------- |
| Table 4 = Digital Outputs |
NOTE: - the survival range of the ADM is 0 - 1900 hPa
- accuracy = three sigma tolerance at time of delivery over -15 deg. C to +85 deg. C range at thermal steady state. (It does not include long-term drift).
- accuracy = three sigma tolerance at time of delivery over -15 deg. C to +85 deg. C range at thermal steady state. (It does not include long-term drift).
| --------------------------------------------------------------------- |
| ! Bit !Data ! |
| ! Position ! ! |
| !-------------------------------------------------------------------! |
| ! 1-8 !Octal Label 270 ! |
| ! 9-10 !SDI ! |
| ! 11-12 !Logic 0 ! |
| ! 13-16 !LSD device revision number (currently 4H) ! |
| ! 17-20 !MSD device revision number (currently 0H) ! |
| ! 21-24 !LS device revision letter (currently CH) ! |
| ! 25-28 !MS device revision letter (currently AH) ! |
| ! 29 !Logic 0 ! |
| ! 30-31 !Logic 0. Set the SSM to Normal Operation for a discrete ! |
| ! !maintenance word ! |
| ! 32 !Odd parity ! |
| --------------------------------------------------------------------- |
| Table 5 = Discrete Word 1 (Label 270) |
| --------------------------------------------------------------------- |
| ! Bit !Data ! |
| ! Position ! ! |
| !-------------------------------------------------------------------! |
| ! 1-8 !Octal Label 271 ! |
| ! 9-10 !SDI ! |
| ! 11-13 !Logic 0 ! |
| ! 14 !ADM LRU Status ! |
| ! 15 !Pin configuration status ! |
| ! 16 !Environment status ! |
| ! 17-24 !Current fault byte matrix ! |
| ! 25-28 !Word counter ! |
| ! 29 !Logic 0 ! |
| ! 30-31 !Logic 0. Set the SSM to Normal Operation for a discrete ! |
| ! !maintenance word ! |
| ! 32 !Odd parity ! |
| --------------------------------------------------------------------- |
| Table 6 = Discrete Word 2 (Label 271) |
| --------------------------------------------------------------------- |
| ! Bit !Data ! |
| ! Position ! ! |
| !-------------------------------------------------------------------! |
| ! 1-8 !Octal Label 377 ! |
| ! 9-10 !SDI ! |
| ! 11-14 !LSD equipment identification (8H) ! |
| ! 15-18 !MSD equipment identification (3H) ! |
| ! 19-29 !Logic 0 ! |
| ! 30-31 !Logic 0. Set the SSM to Normal Operation for a discrete ! |
| ! !maintenance word ! |
| ! 32 !Odd parity ! |
| --------------------------------------------------------------------- |
| Table 7 = Equipment Ident (Label 377) |
| --------------------------------------------------------------------- |
| ! Bit !Data ! |
| ! Position ! ! |
| !-------------------------------------------------------------------! |
| ! 1-8 !Octal Label 040 ! |
| ! 9-10 !SDI ! |
| ! 11-12 !Logic 0 ! |
| ! 13-16 !LSD software revision number ! |
| ! 17-20 !MSD software revision number ! |
| ! 21-24 !LSD manufacturer ident number (1H) ! |
| ! 25-28 !MSD manufacturer ident number (0H) ! |
| ! 29 !Logic 0 ! |
| ! 30-31 !Logic 0. Set the SSM to Normal Operation for a discrete ! |
| ! !maintenance word ! |
| ! 32 !Odd parity ! |
| --------------------------------------------------------------------- |
| Table 8 = Software Ident. (Label 040) |
D. Total Air Temperature (TAT) Sensor
The aircraft is equipped with two TAT sensors with two sensing elements each. The sensing elements of the sensor have variable resistances. The TAT sensor 1 is linked to the ADR portion of the ADIRUs 1 and 3, the TAT sensor 2 is linked to the ADR portion of the ADIRU 2.
The TAT sensors are set at 2.33 m from the nose and at 0.60 m of the aircraft axis below the fuselage. The TAT sensor 1 is located on the left side and the TAT sensor 2 on the right side.
The air flow enters the scoop of the sensor, goes through a calibrated choke and flows over the hermetically-sealed platinum resistance sensing element where the temperature is measured. The speed of the flow over the element is controlled by the choke in the element tube.
The ADR portion is designed to operate with 500 ohms (at 0 deg. C) temperature sensor unit corresponding to the basic Callender - Van Dusen equation. To improve the accuracy of the sensor, a network of precision resistors is used. This technique is identified by the term Precision Calibration Interchangeability (PCI).
These sensors are heated with 115 VAC through the probe heating system. The heating element must not be energized on the ground.
The heating element is implanted in the scoop and strut and keeps the probe free of ice under the most severe icing conditions.
The aircraft is equipped with two TAT sensors with two sensing elements each. The sensing elements of the sensor have variable resistances. The TAT sensor 1 is linked to the ADR portion of the ADIRUs 1 and 3, the TAT sensor 2 is linked to the ADR portion of the ADIRU 2.
The TAT sensors are set at 2.33 m from the nose and at 0.60 m of the aircraft axis below the fuselage. The TAT sensor 1 is located on the left side and the TAT sensor 2 on the right side.
The air flow enters the scoop of the sensor, goes through a calibrated choke and flows over the hermetically-sealed platinum resistance sensing element where the temperature is measured. The speed of the flow over the element is controlled by the choke in the element tube.
The ADR portion is designed to operate with 500 ohms (at 0 deg. C) temperature sensor unit corresponding to the basic Callender - Van Dusen equation. To improve the accuracy of the sensor, a network of precision resistors is used. This technique is identified by the term Precision Calibration Interchangeability (PCI).
These sensors are heated with 115 VAC through the probe heating system. The heating element must not be energized on the ground.
The heating element is implanted in the scoop and strut and keeps the probe free of ice under the most severe icing conditions.
NOTE: Probe ice protection is described in 30-31-00.
E. Angle Of Attack (AOA) Sensor
The aircraft is equipped with three AOA sensors. Two are located on the left side and one on the right side of the fuselage. Each of these AOA sensors is respectively linked to each ADR portion of the ADIRUs. The AOA sensors 1 and 3 are set at 6.08 deg. and 31 deg. below the fuselage datum line (Z = 0) on the left side. The AOA sensor 2 is set at 6.08 deg. below the fuselage datum line (Z = 0) on the right side.
The angle of attack sensor is of the wind vane type. Its sensing element is a small wing which is positioned in the direction of the airflow. The small wing is mechanically linked to a free-turn shaft which drives the devices transmitting the local angle of attack signal. These transmitting devices are made up of resolver transformers which convert the angular information into proportional electrical information (angle sine and cosine). The resolvers are supplied with a 26 VAC signal. The same signal is also received by the ADIRU as a reference for the decoding of AOA values. Each sensor has three resolver outputs but only two are wired to the ADIRU.
The whole mechanism is stabilized around the rotation axis. In addition, a damping device enables a satisfactory dynamic response to be obtained (filtering of mechanical oscillation).
A self-regulated heating element (PTC resistors: positive coefficient of temperature) inserted into the vane eliminates or avoids icing. It is supplied with 115 VAC through the PHC (Ref. AMM D/O 30-31-00-00).
The AOA sensor is equipped with a self-test device which is activated by a 28 VDC signal, from the ADR (through the relay 21FP1, 21FP2 or 21FP3) when the test is entered via the maintenance system (CFDIU and MCDU). The self-test positions the vane at a resolver angle of +15 deg. (left side test) or -15 deg. (right side test).
The mounting and wing of AOA resolvers determine the relationship between the measured resolver angle and the indicated angle of attack. This relationship for each resolver input is as follows:
The ADRs receive the same 26 VAC, 400 Hz reference as the AOA resolvers.
This reference is common to both AOA resolver inputs 1 and 2.
Characteristics:
The accuracy of the AOA sensor, at 100 knots, is +/-0.3 deg.
The aircraft is equipped with three AOA sensors. Two are located on the left side and one on the right side of the fuselage. Each of these AOA sensors is respectively linked to each ADR portion of the ADIRUs. The AOA sensors 1 and 3 are set at 6.08 deg. and 31 deg. below the fuselage datum line (Z = 0) on the left side. The AOA sensor 2 is set at 6.08 deg. below the fuselage datum line (Z = 0) on the right side.
The angle of attack sensor is of the wind vane type. Its sensing element is a small wing which is positioned in the direction of the airflow. The small wing is mechanically linked to a free-turn shaft which drives the devices transmitting the local angle of attack signal. These transmitting devices are made up of resolver transformers which convert the angular information into proportional electrical information (angle sine and cosine). The resolvers are supplied with a 26 VAC signal. The same signal is also received by the ADIRU as a reference for the decoding of AOA values. Each sensor has three resolver outputs but only two are wired to the ADIRU.
The whole mechanism is stabilized around the rotation axis. In addition, a damping device enables a satisfactory dynamic response to be obtained (filtering of mechanical oscillation).
A self-regulated heating element (PTC resistors: positive coefficient of temperature) inserted into the vane eliminates or avoids icing. It is supplied with 115 VAC through the PHC (Ref. AMM D/O 30-31-00-00).
The AOA sensor is equipped with a self-test device which is activated by a 28 VDC signal, from the ADR (through the relay 21FP1, 21FP2 or 21FP3) when the test is entered via the maintenance system (CFDIU and MCDU). The self-test positions the vane at a resolver angle of +15 deg. (left side test) or -15 deg. (right side test).
The mounting and wing of AOA resolvers determine the relationship between the measured resolver angle and the indicated angle of attack. This relationship for each resolver input is as follows:
| ------------------------------------------------------------------------ |
| ! ! Indicated AOA: ! +85 ! +60 ! +25 ! 0 ! -35 ! |
| ! AOA 1 and AOA 3 !----------------------------------------------------! |
| ! in degrees ! Resolver angle: ! -60 ! -35 ! 0 ! +25 ! +60 ! |
| ------------------------------------------------------------------------ |
| ! ! Indicated AOA: ! +85 ! +60 ! +25 ! 0 ! -35 ! |
| ! AOA 2 !----------------------------------------------------! |
| ! in degrees ! Resolver angle: ! +60 ! +35 ! 0 ! -25 ! -60 ! |
| ------------------------------------------------------------------------ |
The ADRs receive the same 26 VAC, 400 Hz reference as the AOA resolvers.
This reference is common to both AOA resolver inputs 1 and 2.
Characteristics:
| Excitation : 26 V 400 Hz |
| Phase shift : 18 deg. to 30 deg. |
| Resolver transformer |
| ratio RT : 0.4029 to 0.4629 |
| Rotor impedance : Zro = 125 + j175 ohms +/-20% |
| Stator impedance : Zso = 115 + j90 ohms +/-30% |
| Range : +/-60 deg. |
| Scale factor : 1 deg. resolver/1 deg. local AOA |
The accuracy of the AOA sensor, at 100 knots, is +/-0.3 deg.
F. Selector Switches
The two selector switches AIR DATA and ATT HDG are rotary selector switches with three positions: CAPT/3, NORM and F/O/3.
These selector switches are used for the functions listed below (Ref. the respective section for more details):
The two selector switches AIR DATA and ATT HDG are rotary selector switches with three positions: CAPT/3, NORM and F/O/3.
These selector switches are used for the functions listed below (Ref. the respective section for more details):
- AIR DATA SEL SW (15FP):
34-14-00 Selection of the ADR used by the IR3
34-52-00 ATC mode S
31-68-00 DMC
22-85-00 FMGC - ATT HDG SEL SW (13FP):
34-11-00 Power Supply
34-14-00 Selection of the ADR used by the IR3
34-41-00 Weather Radar
31-68-00 DMC
22-85-00 FMGC.
G. Dataloading Connectors
Three 53-pin connectors support the ARINC 615-A ADIRU dataloading operations. These connectors are used to wire the Portable Data Loader (PDL) tool to each ADIRU (connector 179VC for ADIRU1, 192VC for ADIRU2 and 191VC for ADIRU3).
They provide data transmission (Tx and Rx), 28V for PDL power supply and various signals to implement the Load Enable logic.
Three 53-pin connectors support the ARINC 615-A ADIRU dataloading operations. These connectors are used to wire the Portable Data Loader (PDL) tool to each ADIRU (connector 179VC for ADIRU1, 192VC for ADIRU2 and 191VC for ADIRU3).
They provide data transmission (Tx and Rx), 28V for PDL power supply and various signals to implement the Load Enable logic.