Power Function; Altitude Functions - Garmin GTX 32 Installation Manual

4.2

Power Function

Power Input requirements are listed in the following tables. The power-input pins accept 14/28 Vdc.
Switched Power Out is a power source available for devices such as a remote digital altitude encoder.
Refer to Appendix C for power interconnections.
4.2.1 Aircraft Power
Pin Name
AIRCRAFT POWER 1
AIRCRAFT POWER 2
SWITCHED POWER OUT
POWER GROUND
SIGNAL GROUND
4.3

Altitude Functions

Altitude functions with pin assignments are shown for reference in connection to the GNS 480 (CNX80)
system. When installed as part of a Garmin Integrated Flight Deck system, altitude data is received from
the GIA 63 in RS-232 format.
Parallel gray code altitude inputs are considered active if either the voltage to ground is < 1.9 V or the
resistance to ground is < 375 Ω. These inputs are considered inactive if the voltage to ground is
11-33 Vdc. Refer to figures in Appendix C for parallel gray code and serial data altitude interconnection.
Carefully check encoder input lines for correct connection after wiring is complete.
The GTX 32 contains internal altitude code line isolation diodes to prevent
the unit from pulling the encoder lines to ground when the transponder is
turned off.
If two separate altimeters are connected to the GTX 32, one providing
parallel gray code and the other, serial data, the unit selects only one for use
at a time, with serial data input receiving the highest priority.
For altimeters that can be connected in both serial data and parallel gray code
format, such as the Garmin GAE 43 (Garmin P/N 013-00066-00), select one
or the other but not both wiring connections.
When connecting two GTX 32 transponders to a GPS, the unit can only
receive RS-232 serial data from one unit at a time. Use a DPDT switch to
connect both serial data and External Standby Select. Refer to Figure C-4
Sheets 1 and 2.
Page 4-2
Revision F
Table 4-2. Aircraft Power Pin Assignments
NOTES
Connector Pin
P3271
15
P3271
23
P3271
14
P3271
13
P3271
25
GTX 32 Installation Manual
190-00303-60
I/O
In
In
Out
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