Discrete I/O; Table 5-7 Altitude Inputs; Table 5-8 Discrete Inputs And Outputs; Gray Code Altitude Input - Garmin GTX 3X5 Series Installation Manual

5.5.2 Gray Code Altitude Input

The GTX 3X5 accepts ten Gray code altitude discrete inputs.
The Gray code inputs are pulled down for active, or open for inactive.
The GTX 3X5 includes internal isolation diodes on the Gray code inputs to prevent the unit from pulling the encoder
lines to ground when the transponder is turned off.
ALTITUDE A1* or CONFIGURABLE*
ALTITUDE A2* or CONFIGURABLE*
ALTITUDE A4* or CONFIGURABLE*
ALTITUDE B1* or CONFIGURABLE*
ALTITUDE B2* or CONFIGURABLE*
ALTITUDE B4* or CONFIGURABLE*
ALTITUDE C1* or CONFIGURABLE*
ALTITUDE C2* or CONFIGURABLE*
ALTITUDE C4* or CONFIGURABLE*
ALTITUDE D4* or CONFIGURABLE*
ALTITUDE GROUND
5.6

Discrete I/O

Active-Low discrete inputs are considered active if either the voltage to ground is <3.5 VDC or the resistance to ground
is <375 ohms. These inputs are considered inactive if the voltage to ground is 6.5-33 VDC or the resistance to ground
is >100 kilohm.
The GTX 3X5 has discrete outputs that are configurable. Each is an open drain output capable of sinking 250 milliamp
when active. For discrete input and output configuration refer to table 6-7 and table 6-8.
EXTERNAL STANDBY SELECT* or CONFIGURABLE*
XPDR FAIL 1* or CONFIGURABLE*
EXTERNAL IDENT SELECT* or CONFIGURABLE*
AUDIO INHIBIT 2* or CONFIGURABLE*
SQUAT SWITCH* or CONFIGURABLE*
AIR DATA SELECT* or CONFIGURABLE*
CONFIGURABLE DISCRETE 1*
CONFIGURABLE DISCRETE 2 *
CONFIGURABLE DISCRETE 11*
CONFIGURABLE DISCRETE 12*
190-01499-02
Rev. 9

Table 5-7 Altitude Inputs

Pin Name

Table 5-8 Discrete Inputs and Outputs

Pin Name
Connector Pinout Information
Connector Pin
P3251 10
P3251 32
P3251 53
P3251 11
P3251 33
P3251 54
P3251 12
P3251 34
P3251 55
P3251 13
P3251 56
Connector Pin
P3251 14
P3251 17
P3251 36
P3251 37
P3251 57
P3251 58
P3251 15
P3251 16
P3252 13
P3252 14
GTX 3X5 Transponder TSO Installation Manual
I/O
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I
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I
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I/O
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I/O
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I/O
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