Garmin G3X Installation Manual page 348

23.12.3.2 RS-485 Input
The GSU 25 contains one channel of RS-485 serial data communications for receiving data from the
GMU 22.
RS-485 RX A
RS-485 RX B
23.12.3.3 CAN Bus
This data bus conforms to the BOSCH standard for Controller Area Network 2.0-B. This bus complies
with ISO 11898. See Section 2.3.1.3
CAN BUS HI
CAN BUS LOW
23.12.4 Temperature Inputs
Temperature input is used for Outside Air Temperature (OAT) computations. The temperature input is a
three-wire temperature probe interface. OAT Power Out and OAT High are connected internally at the
OAT probe. A GTP 59 or other supported temperature probe is required for the ADAHRS (GSU 25/73)
installation that is configured as ADAHRS 1. The GTP 59 is a Resistive Temperature Device (RTD).
Refer to Figure 18-2 for the temperature probe interconnect.
OAT POWER
OAT HIGH
OAT LOW
23.12.5 Unit ID
Refer to Figure 24-1.5 for connection drawing.
UNIT ID 1 GROUND
UNIT ID 1
Unit ID
ADAHRS #1 Leave pins 4 and 5 (of J252) unconnected
ADAHRS #2 Connect pin 4 (of J252) to pin 5 (of J252)
Connect pin 4 (of J252) to pin 5 (of J252) and connect RS-232 RX 1 to RS-232 TX 1
ADAHRS #3
(pins 4 and 5 on J251)
190-01115-01
Rev. AA
Pin Name
for details.
Pin Name
Pin Name
Pin Name
G3X/G3X Touch Installation Manual - LRU Pinouts
Connector
J252
J252
Connector
J251
J251
Connector
J252
J252
J252
Connector
J252
J252
Comment
Pin I/O
12 In
13 In
Pin I/O
1 I/O
2 --
Pin I/O
1 Out
2 In
3 In
Pin I/O
4 --
5 In
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