190-01115-01
G3X/G3X Touch Installation Manual - LRU Pinouts
Rev. AC
Page 25-79
25.17.3 Aircraft Power
Power input requirements are listed in the following tables. The power input pins accept 14/28 Vdc. Refer
to Figure C-1 and C-2 for power interconnections. AIRCRAFT POWER 1 and AIRCRAFT POWER 2 are
“diode ORed” to provide power redundancy.
25.17.4 Discrete Functions
25.17.4.1 Discrete Outputs
External suppression should be connected if a DME or TCAS is installed in the aircraft avionics system.
The GTX 23 suppression I/O pulses may not be compatible with all models of DME or TCAS. Known
incompatible DME units include the Bendix/King KN 62, KN 64 and KNS 80. These models have an
output-only suppression port and can be damaged by the GTX 23 mutual suppression output. In this case,
do not connect the GTX 23’s suppression pin to the incompatible unit’s suppression pin; however, do
connect the GTX 23’s suppression pin to any other compatible unit’s suppression pin.
25.17.4.2 Discrete Inputs
Sink current is internally limited to 200 uA max for a grounded input
EXTERNAL IDENT SELECT (remote IDENT) is a momentary input. When grounded, it activates the
IDENT pulse for 18 seconds in Mode A replies.
EXTERNAL STANDBY SELECT (remote STANDBY) is not a momentary input. When EXTERNAL
STANDBY SELECT is grounded, the GTX 23 operates in standby mode. In this mode, the transponder
will not squitter or reply to interrogations.
TIS CONNECT SELECT is a momentary input. When grounded, it toggles whether TIS-A is in standby
or operating.
Pin Name
Connector
Pin
I/O
AIRCRAFT POWER 1
J2301
21
In
AIRCRAFT POWER 1
J2301
42
In
AIRCRAFT POWER 2
J2301
56
In
AIRCRAFT POWER 2
J2301
60
In
POWER GROUND
J2301
39
--
POWER GROUND
J2301
58
--
Pin Name
Connector
Pin
I/O
EXTERNAL SUPPRESSION I/O (TXP/DME)
J2301
31
I/O
Pin Name
Connector
Pin
I/O
EXTERNAL IDENT SELECT*
J2301
12
In
EXTERNAL STANDBY SELECT*
J2301
13
In
TIS CONNECT SELECT
J2301
46
In
*Inactive State: 10
Vin
33 Vdc or Rin
100 k
Ω
, Active State: Vin
1.9 Vdc with
75 uA sink current, or Rin
375
Ω
