Serial Data - Garmin GNC 420A Installation Manual

4.6

SERIAL DATA

4.6.1 Serial Data Function
4.6.1.1 RS-232
The 400 Series unit is capable of interfacing with other aviation instruments by transmitting RS-232 Type
1 (often known as ARNAV format) and Type 2 (often known as Northstar format) data on the GPS RS 232
OUT 1 port. The data consists of the following (refer to Appendix C for a detailed data format
description):
Current latitude, longitude, and GPS altitude in feet (see Note below)
Current velocity vector (ground speed and direction of velocity vector over the ground)
Distance, bearing, desired track, and cross track error to destination waypoint
Destination waypoint identifier, sequence in route, position (latitude and longitude), and magnetic variation
Magnetic variation and navigation and warning status
Aviation RS-232 data may be transmitted with or without the current GPS altitude in
feet. Refer to section 5.2.2.
The 400 Series unit can receive pressure altitude, air data, and fuel data from certain systems on the GPS
RS 232 IN 1 port.
The 400 Series unit can communicate with a Ryan TCAD 9900B system using the GPS RS 232 OUT 2 and
GPS RS 232 IN 2 lines to display traffic information on the 400 Series unit.
If two 400 Series units are installed in an aircraft, the GPS RS 232 OUT 3 and GPS RS 232 IN 3 lines may
be cross-connected to crossfill flight plans and user-defined waypoints from one 400 Series unit to the
other.
The GNS 480 will not crossfill to a GPS 500, GNS 530/530A, GPS 400, GNC
420/420A, or a GNS 430/430A.
The 400 Series unit can communicate with a BF Goodrich WX-500 Stormscope using the GPS RS 232
OUT 4 and GPS RS 232 IN 4 lines to display lightning strike information on the 400 Series unit.
4.6.1.2 ARINC 429
The data output on the GPS ARINC 429 OUT port depends on the configuration (refer to section 5.2.1).
Below is a list of the configurations and the labels output for each one:
1. ARINC 429
2. GAMA 429
3. GAMA 429 Graphics
4. GAMA 429 Graphics w/Int
Label #
001
002
012
074G
075G
100
100G
113G
114
115
116
116G
121 Horizontal Command (to Autopilot)
400 SERIES INSTALLATION MANUAL
190-00140-02
NOTE
NOTE
Parameter Name
Distance to Go (BCD)
Time to Go (BCD)
Ground Speed (BCD)
Data Record Header
Active Wpt From/To Data
Selected Course 1
Selected Course 1
Message Checksum
Desired Track (True)
Waypoint Bearing (True)
Cross Track Distance
Cross Track Distance
1 2 3 4
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