Garmin G3X - F.5.5 Discrete I;O; F.5.5.1 Discrete Inputs; F.5.5.2 Discrete Outputs

190-01115-01 G3X™/G3X Touch™ Avionics Installation Manual
Rev. AV Page F-13
F.5.5 Discrete I/O
F.5.5.1 Discrete Inputs
The GSU 73 has 4 configurable discrete inputs.
When configured as Active Low, the inputs conform to the following specification:
ACTIVE: Vin < 3.5 VDC, or Rin < 375 Ω
INACTIVE: Vin > 8 VDC, or Rin > 100k Ω
When configured as Active High, the inputs conform to the following specification:
ACTIVE: Vin > 8 VDC, or Rin > 100k Ω
INACTIVE: Vin < 3.5 VDC, or Rin < 375 Ω
F.5.5.2 Discrete Outputs
The GSU 73 has 2 annunciator outputs, these outputs do not require any configuration and can be
optionally wired to an external annunciator. Discrete Out 1 acts as a master warning annunciator and is
active any time a warning CAS message (Red Alert) is displayed on the PFD. Discrete Out 2 acts as a
master caution annunciator and is active any time a caution CAS message (Yellow Alert) is displayed on
the PFD. Reference Section 26
for wiring guidance.
DISCRETE OUT 1 is "master warning" - goes low when a red (warning) CAS alert is active.
DISCRETE OUT 2 is "master caution" - goes low when a yellow (caution) CAS alert is active.
The two states of these outputs are as follows:
INACTIVE: Floating (can be pulled up to externally sourced Vout in the range 0 ≤ Vout ≤ 33 VDC)
Leakage current in the INACTIVE state is typically ≤ 10 uA to ground
ACTIVE: Vout ≤ 0.5 VDC with ≤ 20 mA sink current
Sink current must be externally limited to 20 mA max
Pin Connector Pin Name I/O
9 J731 DISCRETE IN* 1 IN
10 J731 DISCRETE IN* 2 IN
11 J731 DISCRETE IN* 3 IN
12 J731 DISCRETE IN* 4 IN
*Indicates Active Low
Pin Connector Pin Name I/O
13 J731 DISCRETE OUT* 1 OUT
14 J731 DISCRETE OUT* 2 OUT
*Indicates Active Low