User's Manual

SYSTEM DESCRIPTION AND INSTALLATION MANUAL
TCAS 3000 Traffic Alert and Collision Avoidance System
34−43−23
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Page 4−32
15 Dec 2005
Table 4−5. 41−Pin VSI/TRA Interface Descriptions (cont)
Connector Pin
Designation
Functional Description
J1−16 VERTICAL SPEED 26 V ac, 400 HZ REFERENCE INPUT (LO):
See pins 4 and 5.
J1−17 CONFIGURATION STRAP #3 INPUT (NO):
The VSI/TRA utilizes configuration strapping so unique aspects of any given installation
may be identified and its functions supported. Each configuration strap (CS), and its
associated function, becomes active when connected to program common, (J1−15). The
inactive state of CS3 is open. This pin is monitored but unused in the −84X units. In −86X
units it is paired with pin J1−34 (CS2) to configure the Lighting Curve and in −88X and
−89X units it is paired with pin J1−41 (CS8) to select the desired Filter Time Constant.
See pins 34 and 41.
J1−18 PRESSURE TRANSDUCER MODULE POWER OUTPUT (COMMON):
An optional ACSS PTM may be used in an installation to supply ARINC 429 vertical
speed information to the VSI/TRA. Pins 18, 19, and 20 supply input power to the PTM.
Pin J1−18 is the power return pin and is connected to PTM pin 8.
J1−19 PRESSURE TRANSDUCER MODULE −15 V dc POWER OUTPUT:
See pin 18. Connects to PTM pin 11.
J1−20 PRESSURE TRANSDUCER MODULE +15 V dc POWER OUTPUT:
See pin 18. Connects to PTM pin 5.
J1−22 CHASSIS GROUND INPUT:
Connected to aircraft frame. Also used to connect ARINC cable shields to the chassis.
J1−23 115 V ac, 400 HZ POWER INPUT (COMMON):
See pin 40. Connect to aircraft AC ground.
J1−24, 25 REMOTE LIGHT SENSOR INPUT: (J1−24 LOW, J1−25 HIGH)
This input at pins 24 and 25 provides a means of controlling the VSI/TRA back lighting via
a remote light sensor already present in some aircraft (Douglas and Boeing). The
VSI/TRA has its own built−in sensor and therefore a remote light sensor need not be
used in all installations. Program the VSI/TRA for a remote light sensor, as described
under pin 34.
J1−26 ARINC 429 (A) TCAS TA/RA DATA INPUT:
Traffic and Resolution Advisory data is supplied to the VSI/TRA from the TCAS computer
unit via this high speed ARINC 429 data bus. Paired with pin 11.
J1−27 ARINC 429 (A) VERTICAL SPEED NO. 1 INPUT:
This is the primary ARINC 429 input bus to the VSI/TRA. This pin accepts high or low
speed ARINC 429 vertical speed data (Label 212). Its use is determined by the source
select discrete and configuration straps CS0 and CS1 (pins 31, 32, and 33 respectively).
Paired with pin 12.
J1−29 TA/RA VALID DISCRETE OUTPUT (NO):
This output discrete indicates the ability of the VSI/TRA to perform as a resolution
advisory and/or a traffic advisory display. If the VSI/TRA fails, this discrete presents an
open. Normal operation causes a ground. This discrete is monitored by the TCAS
computer unit.