190-01115-01
G3X/G3X Touch Installation Manual - LRU Pinouts
Rev. AC
Page 25-57
25.13.2 Aircraft Power
The GSU 25 can operate using power from one or both inputs (AIRCRAFT POWER 1 AND AIRCRAFT
POWER 2). The pins are internally connected using diodes to prevent current from flowing between the
two power inputs. AIRCRAFT POWER 2 is for connecting to an alternate power source, such as on
aircraft with two electrical buses.
NOTE
The GSU 25 magnetometer power output pin is intended for use only with the GMU 22.
Do not connect the GMU 11 or any other device to this pin.
The GSU 25 outputs supply voltage to the GMU 22 via pins 6 & 7.
25.13.3 Serial Data
25.13.3.1 RS-232
2 Channels of RS-232 RX, and 3 Channels of RS-232 TX data.
RS-232 1: Can optionally be connected to a GDU display to provide a redundant path for attitude data.
Also used to configure a GSU 25 as ADAHRS #3.
RS-232 2: Transmits data to the GMU 22.
RS-232 3: Connects to a GTX transponder to provide pressure altitude data and remote transponder
control. Transponder should only be connected to ADAHRS 1 (not 2 or 3).
Pin Name
Connector
Pin
I/O
AIRCRAFT POWER 1
J251
7
In
AIRCRAFT POWER 2
J251
8
In
POWER GROUND
J251
6
--
POWER GROUND
J251
9
--
Pin Name
Connector
Pin
I/O
+12V MAGNETOMETER POWER
J252
6
Out
MAGNETOMETER GROUND
J252
7
--
Pin Name
Connector
Pin
I/O
RS-232 RX 1
J251
4
In
RS-232 TX 1
J251
5
Out
RS-232 TX 2
J252
15
Out
RS-232 RX 3
J252
10
In
RS-232 TX 3
J252
9
Out