190-01499-02 GTX 3x5 TSO Installation ManualRev. 1 Page 5-95.8.3 HSDB5.8.4 RS-422The RS-422 interface conforms to the electrical specifications of EIA standard RS-422.The RS-422 interface can be configured as an input or an output function depending on the installation.See section ___.5.9 Suppression BusThe external SUPPRESSION BUS is intended for connection to other L-band equipment, such as a DMEor UAT. The SUPRRESION BUS output is active whenever the GTX 3x5 transmits. When driven byanother source, the GTX 3x5 transponder receiver and transmitter functions will be suppressed.The SUPPRESSION BUS is driven to ≥ 18Vdc when the GTX 3x5 transmits. An input voltage of ≥ 10Vdcwill suppress the GTX 3x5.5.10 OAT Temperature InputThe GTX 3x5 includes an Outside Air Temperature (OAT) input, used for OAT and density altitudedisplays.The OAT input uses a current sensor type probe, such as the EDMO P/N 655-PROBE or the Davtron P/NC307PS. The temperature input specification is 1microamp per degree Kelvin (1uA/°K). Connect theprobe red wire to pin 25 and the black wire to pin 3.Pin Name Connector Pin I/OHSDB 1 TX A P3252 6 OHDSB 1 TX B P3252 1 OHSDB 1 RX A P3252 7 IHSDB 1 RX B P3252 2 IHSDB 2 TX A P3252 8 OHDSB 2 TX B P3252 3 OHSDB 2 RX A P3252 9 IHSDB 2 RX B P3252 4 IPin Name Connector Pin I/ORS-422 A P3252 11 I/ORS-422 B P3252 12 I/OPin Name Connector Pin I/OSUPPRESSION BUS P3251 18 I/OPin Name Connector Pin I/OOAT POWER P3251 25 OOAT INPUT P3251 3 I
