Garmin G3X Installation Manual page 366

23.15.11 TX Interlock
TX Interlock Out is an active low output that indicates that this radio's (GTR 20) COM is transmitting.
Connect to another COM's TX Interlock input. TX INTERLOCK OUT will sink 20mA of current and
will output a voltage of 1V or less.
TX Interlock In is an active low input that desenses (protects) the COM receiver when another COM is
transmitting.
TX Interlock In is considered active if either the voltage to ground is ≤3.5 VDC or the resistance to ground
is ≤375 .
TX Interlock In is considered inactive if the voltage to ground is 6.5-33 VDC or the resistance to ground is
>100 k.
TX INTERLOCK OUT
TX INTERLOCK IN*
*Indicates Active Low
23.15.12 Discrete Inputs
These discrete inputs are active low and are configurable.
See Section 32.4.21 when configuring the GTR 20 as the intercom, the configuration options are: None,
Frequency Swap, Pilot Intercom Key, and Copilot Intercom Key. When configuring the GTR 20, but not
as the intercom, the options are: None and Frequency Swap
Active-Low discrete inputs are considered active if either the voltage to ground is ≤3.5 VDC or the
resistance to ground is ≤375 W.
These inputs are considered inactive if the voltage to ground is 6.5-33 VDC or the resistance to ground is
>100 kW.
DISC 1*
DISC 2*
*Indicates Active Low
190-01115-01
Rev. AA
Pin Name
(Section
Pin Name
G3X/G3X Touch Installation Manual - LRU Pinouts
Pin
4
5
32.4.21).
Pin
2
22
I/O
Out
In
I/O
In
In
Page 23-75