General

The TCAS computer transmits interrogations to and receives

replies from other airplanes. Airplanes that are tracked by

TCAS are called targets. The TCAS computer uses these

replies and data from other airplane systems to calculate if a target is a collision threat. The TCAS computer can communicate with other airplanes that have TCAS. The two TCAS computers can use the shared data to perform coordinated maneuvers and avoid potential collisions.

The TCAS computer also gets analog and digital inputs from other airplane systems. These inputs control TCAS and provide data for TCAS to track intruders. The TCAS computer sends display data to the common display system (CDS) display electronic units (DEUs).

The TCAS computer has these circuits:

· Input/output (I/O)

· Speech Processor

· Central processing unit (CPU) and memory

· Suppression circuit

· Signal Processor

· Receiver

· Transmitter

· Beam steering and attenuator

· BITE.