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190-01499-02
GTX 3X5 Transponder TSO Installation Manual
Rev. 4
Page 6-13
DISCRETE OUT
Table 6-8 Discrete Outputs
Figure 6-12 Discrete Out Page
Function
Pin Selection
Description
ALT ALERT
Off
All discrete outputs on P3251
When this discrete is grounded, it indicates a
deviation from the preset altitude setting.
FAIL 1
Off
P3251-17
Failure of transponder causes discrete to
ground.
FAIL 2
Off
All discrete outputs on P3251 or P3252
Failure of transponder causes discrete to open.
RPLY ACTV
Off
All discrete outputs on P3251 or P3252
Discrete grounds when transponder sends
replies to interrogations.
EQUIP STS
Off
All discrete outputs on P3251 or P3252
If the unit needs service soon, this discrete will
switch between open and ground for the first 30
seconds after power up. If after 30 seconds,
there is no detection of ADS-B In/Out failures
the discrete opens. The discrete will ground if
any ADS-B In/Out failures are detected after 30
seconds.
TRFC STBY
Off
All discrete outputs on P3251
Commands TAS/TCAS standby/operate.
Discrete output operation automatically sets
through TAS/TCAS input configuration.
GTX 345 only.
TRFC TEST
Off
All discrete outputs on P3251
Commands TAS/TCAS into test mode.
GTX 345 only.
TRFC ALRT
Off
All discrete outputs on P3251 or P3252
When a traffic alert is active, this discrete will
ground. GTX 345 only.
TCAD SL
Off
All discrete outputs on P3251 or P3252
Supports automatic control and integration with
Ryan TCAD and Avidyne TAS600 Series traffic
systems. GTX 345 only.