User's Manual

SYSTEM DESCRIPTION AND INSTALLATION MANUAL
TCAS 3000 Traffic Alert and Collision Avoidance System
34−43−23
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Page 4−17
15 Dec 2005
Table 4−1. TCAS 3000 Computer Unit Loading/Gradient Specifications (cont)
Connector Pin
Designation
Functional Description
RBP−7G Cable Delay Signal Program Pin (NO)
The cable delay program pins (RBP−7G, RBP−7H, and RBP−7J) convey to the TCAS
computer unit the amount of delay differential between the top and bottom antenna
cables. Pin RBP−7G determines whether a time delay is added to the top or bottom. If
this pin is open, the time delay is added to the top. If this pin is ground (connected to
program pin RBP−7K), the time delay is added to the bottom. The cable delay logic is
given below. Program common for the cable delay program pins is RBP−7K.
RBP−7H RBP−7J Differential
(MSB) (LSB) Delay Adjustment
Open Open 0−50 nsec No Change
Open Ground 51−150 nsec Add 100 nsec delay
Ground Open 151−250 nsec Add 200 nsec delay
Ground Ground 251−350 nsec Add 300 nsec delay
RBP−7H Cable Delay MSB Program (NO)
See RBP−7G.
RBP−7J Cable Delay LSB Program Pin (NO)
See RBP−7G.
RBP−7K Program Common
This is the ground source for use with program pins.
RBP−8A
Thru
RBP−8D
Reserved Program Pins
RBP−8E Self−Test Test Inhibit Program Pin (NO)
This program pin determines if self−test will be inhibited while airborne. If grounded, this
pin inhibits self−test while airborne. If open, self−test is enabled while airborne.
RBP−8F TA/RA Display Symbol Maximum 16 Program Pin (NO)
The TCAS computer unit establishes the number of intruder symbols to be displayed on
the TA display through the program pins RBP−8F, −8G, −8H, −8J, and −8K. This number
can vary between 0 and 31, depending on the programming that is a summation of the
selected pins. Connecting one of these pins to program common (RBP−7K) indicates
the associated pin is not selected and that its value is not included in the summation.
Leaving the pin open designates the associated pin is selected and its value is included in
the summation. The encoded number is placed within the RTS data word (label 357) and
sent to the display. The display should then limit the intruder symbols to this number.
RBP−8G TA/RA Display Symbol Maximum 8 Program Pin (NO)
See RBP−8F.
RBP−8H TA/RA Display Symbol Maximum 4 Program Pin (NO)
See RBP−8F.