Garmin GNC 420AW, Installation Manual

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400W Series Installation Manual Page D-1
190-00356-02 Rev. G
Appendix D 400W SERIES RS-232 AVIATION DATA FORMAT
D.1 Electrical Interface
The output signals are compatible with RS-232C. Data is generated at 9600 baud with a word length of 8
bits, one stop bit, and no parity.
D.2 General Output Format
The 400W Series RS-232 data has the following general format:
STX - ASCII start-of-text character (02 hex)
t1s - Type 1 output sentences (see following paragraphs for description)
t2s - One or more type 2 output sentences (see following paragraphs for description)
ETX - ASCII end-of-text character (03 hex)
D.3 Output Sentence Type 1
The Type 1 output sentences have the following general format:
id - item designator (single ASCII alphabetic character)
dddd - item data (1 to 10 printable ASCII characters)
CR - ASCII carriage return character (0D hex)
LF - ASCII line feed character (0A hex)*
Each Type 1 sentence is output by the 400W Series unit approximately once every second.
The track, desired track, and bearing to waypoint angles, and the magnetic variation are output according
to the current mode of the 400W Series unit (automatic magnetic heading, magnetic variation computed at
last known position; true heading, magnetic variation of E00.0°; or user-defined magnetic heading,
magnetic variation as entered by user).