Garmin GTX 32 Installation Manual page 31

4.3.1 Altimeter Inputs
Pin Name
ALTITUDE D4
ALTITUDE A1
ALTITUDE A2
ALTITUDE A4
ALTITUDE B1
ALTITUDE B2
ALTITUDE B4
ALTITUDE C1
ALTITUDE C2
ALTITUDE C4
ALTITUDE COMMON SIGNAL GROUND
4.3.2 Altimeter Interconnect, Dual GTX 32 Installation
Refer to Figure C-4 Sheets 1 and 2 for Dual GTX 32 altimeter interconnections. A dual GTX 32
installation can accept either parallel wire gray code altimeter input or RS-232 serial data input as shown.
For a complete dual installation containing two encoders, it is best to connect one encoder to each
transponder.
4.3.3 Altimeter Calibration and Checkout
Refer to GNS 480 (CNX80) Installation Manual 560-0982-01 for calibration procedures and gray code
altitude checkout.
4.3.4 Altimeter Selection Priority
When connecting the transponder to a GNS 480 (CNX80), the installer must be aware of the GTX 32
priority for selecting encoded altimeter interconnections. The GTX 32 searches in this sequence for
altitude, and stops when it finds a valid pressure altitude input.
Altitude reporting equipment order of precedence:
1) RS-232 data from GNS 480 (CNX80) or Garmin Integrated Flight Deck system
2) RS-232 Fuel/Air Data Computer (if configured W/ALT.)
3) Parallel wire Gray Code input
4) Shadin Altitude Serializer/Encoder
5) Icarus Altitude Serializer/Encoder
GTX 32 Installation Manual
190-00303-60
Table 4-3. Encoded Altitude Pin Assignments
Connector Pin
P3271
18
P3271
3
P3271
5
P3271
6
P3271
9
P3271
11
P3271
12
P3271
10
P3271
4
P3271
7
P3271
25
Revision F
I/O
In
In
In
In
In
In
In
In
In
In
--
Page 4-3