User's Manual Part 2

T
2
CAS / Part No. 9000000
SYSTEM DESCRIPTION AND INSTALLATION MANUAL
34-43-20
15 Feb 2003
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4--12
Table 4--1. TT--950/951/952 T
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CAS Computer Unit Interface Description (cont)
Connector Pin
Designation
Functional Description
RMP--13A, 13B RA Display No. 1/ARINC 429 Data Recorder Output: [RMP--13A (A), RMP--13B (B)]
These ARINC 429 outputs are configured to output either RA information or for use as an
ARINC 429 data recorder function. The output is configured by program pin RMP--11D.
When RMP--11D is open (standard configuration), the bus is configured for low--speed
(12.5 kbits/s) ARINC 429 operation and RA information is output according to the format
specified for the RA display bus in ARINC 735. When RMP--11D is grounded, the bus is
configured for high--speed (100 kbits/s) ARINC 429 operation and the output supplies TA
and RA information to a 429 data recorder.
RMP--13C, 13D RA Display No. 2/ARINC 429 Data Recorder Output: [RMP--13C (A), RMP--13D (B)]
See RMP--13A.
RMP--13E RA Disp lay No. 2 Status Discrete Input (NO)
This ground/open discrete input (Note 1) provides the functional status of RA Display No.
2. A ground on this pin indicates a valid display. If this discrete is not used by the RA
Display, connect to aircraft ground to prevent RA DISPLAY No. 2 fail message during
self--test.
RMP--13F Landing Gear Discrete Input (NO)
The T
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CAS computer monitors this discrete that indicates the landing gear position.
Landing Gear is a Ground/Open type discrete (Note 1) were an open indicates the gear is
retracted (gear is up) and a ground indicates the gear is extended (gear is down).
RMP--13G Climb Inhibit No. 2 Discrete Input (NO)
See RMP--1J.
RMP--13H, 13J Radio Altimeter No. 1 Input: [RMP--13H (A), RMP--13J (B)]
This input is provided for Low Speed ARINC 429 (12.5 Kbits/s) altitude inputs from an
ARINC 707 digital radio altimeter . Radio altitude data is used for computation of
sensitivity level, inhibit descend advisories, and inhibit aural annunciation when in close
proximity to the ground. Also see RMP--2H.
RMP--13K TCAS System Valid Discrete Output (NO)
This ground/open type discrete output (Note 3) indicates the health status of the T
2
CAS
computer unit to other avionics systems that monitor TCAS system status. This output is
used in retrofit installations where instrumentation needs to monitor TCAS status and the
status is not available across an A429 bus. A ground at this pin indicates normal TCAS
operation. An open indicates a TCAS fault.
RMP--14A, 14B ARINC 429 TX Coordination Bus No. 2 Output: [RMP--14A (A), RMP--14B (B)]
This differential pair output is a high speed ARINC 429 bus (100k bits/second nominal),
that transmits data from the TCAS computer unit to the No. 2 Mode S Transponder .
The labels on this bus are as follows: 273, 274, 275.