500 SERIES INSTALLATION MANUAL
Page C-1
P/N 190-00181-02
Page Rev. B
Appendix C. 500 Series RS-232 Aviation Data Format
C.1 ELECTRICAL INTERFACE
The output signals shall be compatible with RS-232C. Data shall be generated at 9600 baud with a word
length of 8 bits, one stop bit, and no parity.
C.2 GENERAL OUTPUT FORMAT
The 500 Series RS-232 data shall have 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)
C.3 OUTPUT SENTENCE TYPE 1
The Type 1 output sentences shall 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 shall be output by the 500 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 500 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).
The following table describes the Type 1 output sentence item designator (id) and item data (dddd) fields.
If data for these sentences is invalid or unavailable, dashes ("-") are used to fill in all non-blank character
positions.
* The line feed character is not output if the RS-232 port is configured as “Avtn no alt”.
