Garmin GNC 255, Installation Manual, Page: 44 / 138

GTR 225/GNC 255 TSO Installation Manual 190-01182-02
Page 5-6 Rev. B
5.2.2 Lighting Bus
CAUTION
Connection of the lighting bus to incorrect pins can cause damage to the unit that will
require return to the factory for repair. Ensure that the lighting bus is connected to the
correct pins and does not short to any adjacent pins prior to applying power to the unit,
including the lighting bus.
5.2.3 Antennas
The COM and NAV antennas use BNC coaxial connectors on the connector backplate.
5.2.4 Serial Data – RS-232
5.2.4.1 Aviation Out Type 1 and 2 Format
The GTR/GNC is capable of interfacing with other aviation instruments by receiving Aviation Out Type 2
data on RS-232 Input Port 1. The data consists of the following (refer to Section B.1 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 to waypoint
 Cross track error
 Desired track
 Destination waypoint identifier
 Bearing to destination waypoint
 Magnetic variation
 Navigation and warning status
 Waypoint sequence in route
 Waypoint position (latitude and longitude) and magnetic variation
NOTE
Aviation RS-232 data may be transmitted with or without the current GPS altitude in feet.
Refer to Appendix B.
Pin Name Connector Pin I/O
LIGHTING HI 1 P2001 8 In
LIGHTING HI 2 P2001 2 In
LIGHTING LO 1 P2001 22 In
LIGHTING LO 2 P2001 32 In
Pin Name Connector I/O
COM ANTENNA P2003 I/O
NAV ANTENNA P2004 In
Pin Name Connector Pin I/O
RS-232 OUT 1 P2001 1 Out
RS-232 IN 1 P2001 16 In