Discrete Inputs Pin Assignments - Garmin GTX 327 Installation Manual

2.6.2.4 Altimeter Selection Priority
The installer must be aware of the GTX 327 priority for selecting encoded altimeter interconnections.
The GTX 327 searches in this sequence for altitude, and stops when it finds a valid pressure altitude
input.
Only approved devices may provide altitude to the GTX 327 in accordance with 14 CFR Part 91.217. In
addition, all altitude reporting devices installed in the aircraft must meet certification requirements of
14 CFR Part 91.413. The installer must select an altitude reporting device that is a certified altitude
source for the particular aircraft.
Altitude reporting equipment order of precedence:
1) RS-232 Fuel/Air Data Computer (if configured W/ALT.)
2) Parallel wire Gray Code input
3) Shadin Altitude Serializer/Encoder
4) Icarus Altitude Serializer/Encoder
Refer to section 3.3.5 for the altitude data reporting configuration.
2.6.2.5 Discrete Inputs
EXTERNAL IDENT INPUT*
EXTERNAL STANDBY SELECT*
SQUAT SWITCH IN
EXTERNAL SUPPRESSION (TXP/DME)
* These 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.
EXTERNAL IDENT INPUT (remote IDENT) is a momentary input. Refer to figure B4 on page 43 for
the squat switch interconnect and to sections 3.3.6.2. and 3.3.10 for the squat switch configuration.
EXTERNAL STANDBY SELECT (remote STANDBY) is a momentary input used when two GTX 327
systems are installed in an aircraft. Refer to Figure B4 on page 43 for the EXTERNAL STANDBY
SELECT interconnect and to sections 3.3.10 for verifying external standby configuration.
Page 16
Rev J
Table 2-8. Discrete Inputs Pin Assignments
PIN NAME PIN NUMBER
8
16
22
17
GTX 327 Installation Manual
I/O
In
In
In
In/ Out
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