User's Manual Part 2

T
2
CAS / Part No. 9000000
SYSTEM DESCRIPTION AND INSTALLATION MANUAL
34-43-20
15 Feb 2003
Use or disclosure of information on this page is subject to the restrictions in the proprietary notice of this document.
4--37
Table 4--4. XS--950 Data Link Transponder Interface Description (cont)
Connector Pin
Designation
Functional Description
P1A--5J AIR / GROUND #2 DISCRETE INPUT:
This pin and AIR / GROUND #1 Discrete Input (pin P1A--5K) provide a method for the
transponder to automatically determine the Air/Ground status of the aircraft. The status is
used in replies to Mode S interrogations and to inhibit replies to certain types of
interrogations. Both inputs use ground/open logic, where a Ground specifies an “On the
Ground” condition and an Open specifies an “In the Air” condition.
When this pin is connected to the Air/Ground Relay (Squat Switch), the transponder will
not reply to ATCRBS, ATCRBS/Mode S All Call, or Mode S All Call when the input is set
for “On the Ground”. This input should be connected to the Air/Ground Relay for normal
operation.
P1A--5K AIR / GROUND #1 DISCRETE INPUT:
See pin P1A--5J.
When this pin is connected to the Air/Ground Relay (Squat Switch), the transponder
replies to all types of interrogations irregardless of the state of the input. This input allows
the transponder to reply during a ramp test.
P1A--6A, 6B ARINC 429 FLIGHT IDENTIFICATION BUS INPUT: (P1A--6A [A], P1A--6B [B])
This differential pair input is a low speed ARINC 429 bus (12.5k bits/second nominal) that
accepts a flight identification that is contained within four ARINC 429 data words (labels
233, 234, 235 and 236).
P1A--6C, 6D ARINC 615 AIRBORNE DATA LOADER BUS INPUT: (P1A--6C [A], P1A--6D [B])
The Airborne Data Loader interface consists of two high speed ARINC 429 busses (100k
bits/second nominal) and a ground/open logic discrete (pin P1A--6G). The interface
allows for operational transponder software to be loaded into the unit through an onboard
data loader. The standards for this interface are defined in ARINC 615 “Airborne
Computer High Speed Data Loader”.
P1A--6E, 6F ARINC 615 AIRBORNE DATA LOADER BUS OUTPUT: (P1A--6E [A], P1A--6F [B])
See pins P1A--6C, 6D
P1A--6G ADL INPUT LINK A DISCRETE INPUT:
See pins P1A--6C, 6D
P1A--6H, 6J ARINC 575 AIR DATA COMPUTER #1 INPUT: (P1A--6H [A], P1A--6J [B])
This differential pair input is a low speed ARINC 575 bus (12.5k bits/second nominal) that
can be used to input altitude information from an ARINC 575 Air Data System. The
standards for this interface are defined in ARINC Characteristic 575, “Subsonic Air Data
System (Digital) DADS”.
P1A--6K SINGLE / DUAL ANTENNA PROGRAM INPUT:
This pin allows for installation of the transponder in a system with a single bottom
mounted antenna or dual top and bottom mounted antennas. The input uses
ground/open logic as follows:
Ground = Single Bottom Mounted Antenna Configuration
Open = Diversity Antenna Configuration