Page 4-4 GTX 23 Installation ManualRevision A 190-00906-014.3 Serial Data Electrical Characteristics4.3.1 RS-232 Input/OutputRS-232 input #1 is used to receive pressure altitude control commands. RS-232 output #1 provides unitstatus and TIS data. RS-232 #1 input and output are also used for software upgrades.For installations that enable ADS-B, RS-232 input #2 should be connected to a GNS 400W/500W-seriesWAAS enabled unit or a GTN 6XX/7XX series unit. This connection provides the GTX 23 with GPS datafor ADS-B. The RS-232 output #2 is unused on the GTX 23.The RS-232 outputs conform to EIA Standard RS-232C with an output voltage swing of at least ±5 V whendriving a standard RS-232 load. Refer to figures in Appendix C for the RS-232 serial data interconnect.4.3.2 ARINC 429 Input/OutputThe ARINC 429 outputs conform to ARINC 429 electrical specifications when loaded with up to fivestandard ARINC 429 receivers.Pin Name Connector Pin I/ORS-232 OUT 1 P2301 23 OutRS-232 GROUND 1 P2301 43 --RS-232 IN 1 P2301 22 InRS-232 OUT 2 P2301 25 OutRS-232 IN 2 P2301 24 InRS-232 GROUND 2 P2301 50 --Pin Name Connector Pin I/OARINC 429 OUT 1A P2301 37 OutARINC 429 OUT 1B P2301 34 OutARINC 429 OUT 2A P2301 30 OutARINC 429 OUT 2B P2301 28 OutSIGNAL GROUND P2301 51 --SIGNAL GROUND P2301 58 --
