Discrete I/O - Garmin G3X Touch Installation Manual

25.14.5 Discrete I/O

25.14.5.1 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
Pin Connector
9 J731
10 J731
11 J731
12 J731
*Indicates Active Low
25.14.5.2 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 29
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
13 J731
14 J731
*Indicates Active Low
190-01115-01
Rev. AC
DISCRETE IN* 1
DISCRETE IN* 2
DISCRETE IN* 3
DISCRETE IN* 4
for wiring guidance.
DISCRETE OUT* 1
DISCRETE OUT* 2
G3X/G3X Touch Installation Manual - LRU Pinouts
Pin Name
Pin Name
I/O
IN
IN
IN
IN
I/O
OUT
OUT
Page 25-67