Power And Lighting Function; Altitude Functions; Aircraft Power Pin Assignments; Aircraft Lighting Pin Assignments - Garmin GTX 327 Installation Manual

2.6.1 Power and Lighting Function

Power Input requirements and Lighting Bus input are listed in the following tables. The power-input pin
accepts 11-33 Vdc. Switched Power Out is a power source available for devices such as a remote digital
altitude encoder. Refer to figure B4 on page 43 for power and lighting interconnections.
2.6.1.1 Aircraft Power
AIRCRAFT POWER
SWITCHED POWER OUT
POWER GROUND
POWER GROUND
2.6.1.2 Lighting Bus
The GTX 327 unit can be configured to track a 28 Vdc, 14 Vdc, 5 Vdc or 5 Vac lighting bus using these
inputs. The GTX 327 can also automatically adjust for ambient lighting conditions based on the
photocell. Refer to sections 3.3.2 and 3.3.3 for lighting configuration.
14 V/5 V LIGHTING BUS HI
28 V LIGHTING BUS HI

2.6.2 Altitude Functions

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 figure B4 on page 43 for parallel gray code and serial data altitude interconnections.
Carefully check encoder input lines for correct connection after wiring is complete.
The GTX 327 contains internal altitude code line isolation diodes to
prevent the unit from pulling the encoder lines to ground when the
transponder is turned off.
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.
Page 14
Rev J
Table 2-5. Aircraft Power Pin Assignments
PIN NAME
Table 2-6. Aircraft Lighting Pin Assignments
PIN NAME
NOTES
PIN NUMBER
15
14
13
25
PIN NUMBER
24
23
GTX 327 Installation Manual
I/O
In
Out
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--
I/O
In
In
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