Serial Data Electrical Characteristics; Table 4-5 Rs-232 Input/Output; Table 4-6 Arinc 429 Input/Output - Garmin GTX 23 Installation Manual

4.3 Serial Data Electrical Characteristics

4.3.1 RS-232 Input/Output
RS-232 input #1 is used to receive pressure altitude control commands. RS-232 output #1 provides unit
status 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-series
WAAS enabled unit or a GTN 6XX/7XX series unit. This connection provides the GTX 23 with GPS data
for 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
when driving a standard RS-232 load. Refer to figures in Appendix C for the RS-232 serial data
interconnect.
RS-232 OUT 1
RS-232 GROUND 1
RS-232 IN 1
RS-232 OUT 2
RS-232 IN 2
RS-232 GROUND 2
4.3.2 ARINC 429 Input/Output
The ARINC 429 outputs conform to ARINC 429 electrical specifications when loaded with up to five
standard ARINC 429 receivers.
ARINC 429 OUT 1A
ARINC 429 OUT 1B
ARINC 429 OUT 2A
ARINC 429 OUT 2B
SIGNAL GROUND
SIGNAL GROUND
190-00906-01
Rev. C

Table 4-5 RS-232 Input/Output

Pin Name

Table 4-6 ARINC 429 Input/Output

Pin Name
Connector Pin
P2301 23
P2301 43
P2301 22
P2301 25
P2301 24
P2301 50
Connector Pin
P2301 37
P2301 34
P2301 30
P2301 28
P2301 51
P2301 58
GTX 23 Installation Manual
Page 4-5
I/O
Out
--
In
Out
In
--
I/O
Out
Out
Out
Out
--
--