GTX 32 Installation Manual
Page 1-1
190-00303-60 Revision
F
1
GENERAL DESCRIPTION
1.1
Introduction
This manual presents mechanical and electrical installation requirements for installing the Garmin
GTX 32 Transponder as part of a Garmin Integrated Flight Deck.
The GTX 32 can also be incorporated as a remote mounted unit in installations with other compatible
control/display units such as the Garmin GNS 480 (CNX80).
The information in this manual is STC approved. Only the equipment interfaces covered in this manual
are within the scope of the STC. Other equipment may be suitable for use with the GTX 32 but additional
FAA approval may be required. After installation of the GTX 32 in an aircraft not covered by an airframe
manufacturer’s TC, FAA Form 337 must be completed by an appropriately certificated agency to return
the aircraft to service.
1.2
Equipment Description
The Garmin GTX 32 rack-mounted transponder is a radio transmitter and receiver that operates on radar
frequencies, receiving ground radar or TCAS interrogations at 1030 MHz and transmitting a coded
response of pulses to ground-based radar on a frequency of 1090 MHz. The GTX 32 is equipped with
IDENT capability that activates the Special Position Identification (SPI) pulse for 18 seconds.
The GTX 32 replies to Mode A and Mode C interrogation. Mode A replies consist of framing pulses and
any one of 4,096 codes, which differ in the position and number of pulses transmitted. Mode C replies
include framing pulses and encoded altitude.
By replying to ground transmissions or TCAS interrogations, the GTX 32 enables ATC to display aircraft
identification, altitude and groundspeed on ATC radar screens or TCAS traffic indicators.
The GTX 32 is configured to be turned on by the aircraft avionics master bus. Transponder code entry
and function control are accessed through keys on the GDU Primary Flight Displays or the GNS 480
(CNX80).
The GTX 32 features transmit/receive RS-232 data ports. The unit concentrates data from gray code,
RS-232 input data and discrete inputs to the high-speed RS-232 data ports for display on the Garmin
Integrated Flight Deck displays. The unit is designed to feed all outgoing data via RS-232 data ports that
send and receive data to/from the GIA 63 Integrated Avionics Units (IAU) or GNS 480 (CNX80) display.
The GTX 32 can also be incorporated to act as the controller for a GDL 90.
Provision is made for unit software upgrade by means of RS-232 data through rear connector pins. In
installations where the transponder interfaces with a GNS 480 (CNX80) the installation of an optional
connector is highly recommended. If the optional connector is placed in the aircraft, transponder removal
and reinstallation for software upgrade is not required. The software can be changed while the unit is still
mounted inside the aircraft.
