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G3X/G3X Touch Installation Manual - LRU Pinouts
Rev. AC
Page 25-58
25.13.3.2 RS-485 Input
The GSU 25 contains one channel of RS-485 serial data communications for receiving data from the
GMU 22.
25.13.3.3 CAN Bus
This data bus conforms to the BOSCH standard for Controller Area Network 2.0-B. This bus complies
with ISO 11898. See
for details.
25.13.4 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
for the temperature probe interconnect.
25.13.5 Unit ID
Refer to
for connection drawing.
Pin Name
Connector
Pin
I/O
RS-485 RX A
J252
12
In
RS-485 RX B
J252
13
In
Pin Name
Connector
Pin
I/O
CAN BUS HI
J251
1
I/O
CAN BUS LOW
J251
2
--
Pin Name
Connector
Pin
I/O
OAT POWER
J252
1
Out
OAT HIGH
J252
2
In
OAT LOW
J252
3
In
Pin Name
Connector
Pin
I/O
UNIT ID 1 GROUND
J252
4
--
UNIT ID 1
J252
5
In
Unit ID
Comment
ADAHRS #1
Leave pins 4 and 5 (of J252) unconnected
ADAHRS #2
Connect pin 4 (of J252) to pin 5 (of J252)
ADAHRS #3
Connect pin 4 (of J252) to pin 5 (of J252) and connect RS-232 RX 1 to RS-232 TX 1
(pins 4 and 5 on J251)