Lighting Bus; Antennas - Garmin GTX 3x5 Series Installation Manual

The SW PWR OUT is a switched power output source, typically used for powering devices such as a
remote altitude encoder. The SW PWR OUT is active when the GTX 3x5 power is on, and is rated for 1A
max.
The KEEP ALIVE input is used to maintain the GPS real time clock. The keep alive input can be
connected to the aircraft battery.
5.3.1 Power Control Inputs
The power control inputs are used for remote power on/off and enabling the power "auto on" feature.
PWR CONFIG
PWR CONTROL
The PWR CONFIG input is used to enable the remote on/off feature. This is typically connected to ground
for a remote unit installation and left open for a panel mount unit installation.
The PWR CONTROL input is dependent on the PWR CONFIG connection. This can be used as a remote
power on/off control or to enable the power "auto on" feature when the avionics master is turned on.
The PWR CONFIG and PWR CONTROL input function as described in the following table.
PWR PWR
CONFIG CONTROL
Open Open
Open Ground
Ground Open
Ground Ground

5.4 Lighting Bus

The lighting bus input is used to controls the front panel display and keypad brightness using the aircraft
panel lighting bus. The GTX 3x5 can also be configured to adjust the display and keypad brightness for
ambient lighting conditions using an internal photo sensor.
LTNG HI
LTNG LO
The lighting bus input can be configured for 5 Vdc, 14 Vdc, 28 Vdc, or 5 Vac inputs.
When connecting the lighting bus input to a 5 VAC bus, use both the LTNG HI and LTNG LO inputs.
When connecting the light bus input to a DC input, use the LTNG HI input. The return is the unit ground
connection. LTNG LO should be left open.

5.5 Antennas

190-01499-02
Rev. 1
Pin Name
Panel mount
Panel mount
Remote
Remote
Pin Name
Connector
P3251
P3251
Description
Auto on disabled, momentary power switch enabled
Auto on enabled, momentary power switch enabled
Power off
Power on
Connector
P3251
P3251
GTX 3x5 TSO Installation Manual
Pin I/O
59 I
38 I
Pin I/O
19 I
40 I
Page 5-4