Garmin G3X Installation Manual page 316

23.4.8 Serial Data
23.4.8.1 RS-232
5 Channels of RS-232 I/O data.
Pin Name
RS-232 IN 1
RS-232 OUT 1
RS-232 IN 2
RS-232 OUT 2
RS-232 IN 3
RS-232 OUT 3
RS-232 IN 4
RS-232 OUT 4
RS-232 IN 5
RS-232 OUT 5
23.4.8.2 CAN Bus
This data bus conforms to the BOSCH standard for Controller Area Network 2.0-B. This bus complies
with ISO 11898. CAN BUS TERMINATION should be connected to CAN BUS LO for the GDU that is
located at the end of the bus (farthest from the GSU 73), see
Pin Name
CAN BUS HI
CAN BUS LO
CAN BUS TERMINATION
23.4.9 Lighting
The GDU 45X/46X display and keys can be configured to track 28 VDC or 14 VDC lighting busses using
these inputs. These inputs are reference voltage inputs (not power inputs) with a high impedance of
~100 kΩ for pin 43 and ~200 kΩ for pin 26. This backlight level reference signal may be supplied with
something as simple as a 10K potentiometer connected to power and ground (drawing 1 mA @ 14 VDC).
The center tap on this potentiometer is connected to one of the pins (43 or 26) in the following table. For
providing this reference signal to more than one device, a commercially available regulated backlight
voltage reference is recommended.
Pin Name
14V LIGHTING BUS HI
28V LIGHTING BUS HI
190-01115-01
Rev. AA
Connector
P4502/4602
P4502/4602
P4502/4602
P4502/4602
P4502/4602
P4502/4602
P4502/4602
P4502/4602
P4502/4602
P4502/4602
Section 2.3.1.3.3
Connector
P4502/4602
P4502/4602
P4502/4602
Connector
P4502/4602
P4502/4602
G3X/G3X Touch Installation Manual - LRU Pinouts
Pin I/O
47 In
48 Out
14 In
30 Out
29 In
13 Out
23 In
40 Out
24 In
41 Out
for details.
Pin I/O
46 I/O
45 I/O
28 --
Pin I/O
43 In
26 In
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