User's Manual

SYSTEM DESCRIPTION AND INSTALLATION MANUAL
TCAS 3000 Traffic Alert and Collision Avoidance System
34−43−23
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Page 4−18
15 Dec 2005
Table 4−1. TCAS 3000 Computer Unit Loading/Gradient Specifications (cont)
Connector Pin
Designation
Functional Description
RBP−8J TA/RA Display Symbol Maximum 2 Program Pin (NO)
See RBP−8F.
RBP−8K TA/RA Display Symbol Maximum 1 Program Pin (NO)
See RBP−8F.
RBP−9A
Thru
RBP−10K
Reserved Factory Test Pins
Leave these pins unconnected for aircraft installations.
TCAS Computer Unit Left Top Plug (LTP)
LTP−1 Top Antenna 0 Degree Port
J1 on the antenna is color−coded yellow. This antenna port is called the 0 degree port
because it produces a transmission pattern in the forward quadrant of the aircraft. J1 is
physically located toward the rear of the antenna and to the rear of the aircraft when
antenna is properly installed. The TCAS computer unit checks the built−in dc to ground
resistance of this antenna port. It must detect approximately 1000 ohms or TCAS fails its
antenna test.
LTP−2 Top Antenna 270 Degree Port
J2 on the antenna is color−coded black. This antenna port is called the 270 degree port
because it produces a transmission pattern in the left wing quadrant of the aircraft. J2 is
physically located toward the right wing of the aircraft when antenna is properly installed.
The TCAS computer unit checks the built−in dc to ground resistance of this antenna port.
It must detect approximately 8000 ohms or it reports antenna test failure.
LTP−3 Top Antenna 180 Degree Port
J3 on the antenna is color−coded blue. This antenna port is called the 180 degree port
because it produces a transmission pattern in the rear quadrant of the aircraft. J3 is
physically located toward the front of the antenna and to the front of the aircraft when
antenna is installed properly. The TCAS computer unit checks the built−in dc to ground
resistance of this antenna port. It must detect approximately 4000 ohms or it reports
antenna test failure.
LTP−4 Top Antenna 90 Degree Port
J4 on the antenna is color−coded red. This antenna port is called the 90 degree port
because it produces a transmission pattern in the right wing quadrant of the aircraft. J4 is
physically located toward the left wing of the aircraft when antenna is properly installed.
The TCAS computer unit checks the built−in dc to ground resistance of this antenna port.
It must detect approximately 2000 ohms or it reports antenna test failure.
TCAS Computer Unit Left Middle Plug (LMP)
LMP−1 Bottom Antenna 0 Degree Port
J1 on the antenna is color−coded yellow. Same as top antenna 0 degree port (LTP−1).
In addition, this port is used as the omnidirectional antenna connection. The TCAS
computer unit determines that a bottom omnidirectional antenna is installed if it detects
less than 500 Ohms (50 ohms typical) to ground on this pin and an open circuit (>13K
Ohms) at LMP− 2, −3, and −4 or a dc short (<500 Ohms) if unused ports are terminated
at back of mounting tray.