DOC AIRBUS | AMM A320FFWC - ACQUISITION/INTERFACE - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
This note defines the interfaces between the various aircraft systems and the Flight Warning Computer (FWC).
Several signal types are used :
** ON A/C NOT FOR ALL This note defines the interfaces between the various aircraft systems and the Flight Warning Computer (FWC).
Several signal types are used :
- Wired discretes
- Boolean on bus
- Digital on bus
- Analog on synchro
- supplies and miscellaneous.
2. Signal Types
A. Wired Discretes
Each wired discrete is assigned to a computer input pin.
Each wired discrete is assigned to a computer input pin.
(1) P-
This type of discrete is defined by the two states (on data bus):
This type of discrete is defined by the two states (on data bus):
- logic 0 : the computer detects ground
- logic 1 : the computer detects absence of ground.
(2) P+
This discrete is defined by the two states:
This discrete is defined by the two states:
- logic 1 : the computer detects +28VDC
- logic 0 : the computer detects absence of 28VDC.
(3) P- off
- logic 0 : the computer detects disappearance of ground
- logic 1 : the computer detects a permanent ground.
(4) P+ off
- logic 1 : the computer detects disappearance of +28VDC
- logic 0 : the computer detects permanent +28VDC.
NOTE: Some discretes are inversed (P- at logic 1 : ground) for their use in the logics.
There are also output discretes. Controlled by the computer, logic 1 is represented by a ground and logic 0 by open circuit. They permit illumination of an annunciator light or closing of a relay. B. Boolean on Bus
These data have two states.
The computer copies the state of the corresponding bit on one of the ARINC buses addressed to the computer on its input port. Inversely, at output, the computer puts label bits assigned to booleans to be transmitted on its data bus. For example, the computer sets the label 126 SDI 10 bit 9 to 1 on its data bus when it computes AP OFF WARNING.
These data have two states.
The computer copies the state of the corresponding bit on one of the ARINC buses addressed to the computer on its input port. Inversely, at output, the computer puts label bits assigned to booleans to be transmitted on its data bus. For example, the computer sets the label 126 SDI 10 bit 9 to 1 on its data bus when it computes AP OFF WARNING.
C. Digital on Bus
The received data requires a large number of bits available on an input bus label.
E.g., on label 370 (SDI : 01) from DMC/L, 16 bits are used for DECISION HEIGHT which gives a range of 8192 feet for a resolution of 0.125 feet.
In the same way on label 173 (SDI : 01) from ILS 1 receiver, 12 bits are used for LOC DEVIATION which gives a range of 0.4DDM for a resolution of 0.0001 DDM.
The received data requires a large number of bits available on an input bus label.
E.g., on label 370 (SDI : 01) from DMC/L, 16 bits are used for DECISION HEIGHT which gives a range of 8192 feet for a resolution of 0.125 feet.
In the same way on label 173 (SDI : 01) from ILS 1 receiver, 12 bits are used for LOC DEVIATION which gives a range of 0.4DDM for a resolution of 0.0001 DDM.
D. Analog on Synchro
The data received on three of the input pins is of the same type as that which normally supplies an indicator with a pointer (the combination of amplitudes of the three voltages at 400 Hz privileges a direction in a plane). Therefore the data is essentially angular.
The data received on three of the input pins is of the same type as that which normally supplies an indicator with a pointer (the combination of amplitudes of the three voltages at 400 Hz privileges a direction in a plane). Therefore the data is essentially angular.
E. Power Supplies
The FWC 1 is supplied by the 115VAC ESS BUS 401 XP-C via circuit breaker 3WW.
The FWC 2 is supplied by the 115VAC BUS 2 204 XP-A via circuit breaker 2WW.
The FWC 1 is supplied by the 115VAC ESS BUS 401 XP-C via circuit breaker 3WW.
The FWC 2 is supplied by the 115VAC BUS 2 204 XP-A via circuit breaker 2WW.
F. Miscellaneous
Certain pins are assigned to signals other than those mentioned above.
For example, signals which synchronize audio outputs or test pins intended for software development.
Certain pins are assigned to signals other than those mentioned above.
For example, signals which synchronize audio outputs or test pins intended for software development.
3. Interface Tables
A. Interface Tables
All input/output signals are given in tabular form in the ECAM System Logic Data (ESLD) (FWC Signals).
All input/output signals are given in tabular form in the ECAM System Logic Data (ESLD) (FWC Signals).