Garmin G3X Installation Manual page 199

A.3.8 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 GSU 73 installation. The
GTP 59 is a Resistive Temperature Device (RTD). Refer to Figure D-1.2 for the temperature probe
interconnect.
Pin Connector
15 P732
16 P732
35 P732
A.3.9 Frequency Counter Inputs
Digital signals are updated to the display at a rate of 10 times per second (10 Hz). Digital inputs are low
when the signal is ≤ 2 Vdc or the resistance to ground is ≤ 375 Ω, and high when the signal is > 3.5 Vdc
or the resistance to ground is > 100 k Ω.
Pin Connector
17 P732
19 P732
36 P732
38 P732
*Indicates Active Low
The following table lists the minimum frequency, maximum frequency, and duty cycles for each of these
inputs.
Pin Name
RPM
FUEL FLOW
CAP FUEL 1
CAP FUEL 2/FUEL FLOW 2
*Each frequency counter channel will be configured for a high or low speed input based on the signal
being measured.
A.3.10 Fuel Select Outputs
If a resistive fuel level sensor is connected to the FUEL 1 or FUEL 2 inputs, the corresponding FUEL
SENSOR PULL-UP 1 or 2 pin must be connected to the +10V TRANSDUCER POWER pin (58) for the
fuel level sensor to work properly. If using resistive fuel level sensors with the GP 3/FUEL 3 or GP
4/FUEL 4 inputs, connect the high side of the input to +10V power through a 1 kΩ resistor, as shown in
Appendix G.
Pin Connector
76 P732
77 P732
G3X Installation Manual – Pinouts
190-01115-01
Pin Name
OAT PROBE IN HI
OAT PROBE POWER OUT
OAT PROBE IN LO
Pin Name
RPM
FUEL FLOW
CAP FUEL 1
CAP FUEL 2/FUEL FLOW 2
Minimum Frequency
1 Hz
1 Hz
1 Hz
1 Hz
Pin Name
FUEL SENSOR PULL-UP 2 (FUEL 2)
FUEL SENSOR PULL-UP 1 (FUEL 1)
Maximum Frequency
500 Hz/100 KHz*
500 Hz/100 KHz*
500 Hz/100 KHz*
500 Hz/100 KHz*
I/O
IN
OUT
IN
I/O
IN
IN
IN
IN
Duty
Cycle
50%
50%
50%
50%
I/O
OUT
OUT
Page A-15
Revision E