Appendix B - Serial Interface SpecificationsGNS 480 (CNX80) Installation Manual 560-0982-01 Rev LExample Fuel / Airdata Input DataSA223 223 knots indicated air speedSB230 230 knots true air speedSC101 0.101 machSD+3200 32,000 feet pressure altitudeSE+3312 33,120 feet density altitudeSF+05 +5°C outside air tempSG-03 -3°C true air tempSH010 wind direction at 10° (relative to true north)SI015 wind speed at 15 knotsSJ+03 +3° / second right turnSK-050 -50 feet / second vertical air speedSL359 359° heading (relative to true north)SM0123 12.3 gallons / hour - right engine fuel flowSN0300 30.0 gallons used - right engineSO0131 13.1 gallons / hour - left engine fuel flowSP0310 31.0 gallons used - left engineSQ000 no errorsSR01227 122.7 gallons remainingS*123 Checksum (example only, not actual) end of message stringFigure B-2. Fuel/Air Data Input (S Format)B.1.2.2 “Z” Data FormatThe format of the fuel/air data computer input is as follows, which conforms to the Shadin “Z” formatserial message. Definition of the input message data that the GNS 480 uses is included in Table B-4.Baud rate: ............................................... 9600Data bits: ................................................ 8Stop bits: ................................................ 1Parity: ..................................................... noneExpected input rate: ............................... approx. 1 secondMessage length: ..................................... variable (512 character max.)The serial input message string is expected in the following format. ... .................................................... ASCII “start of text” character (STX = 02h) .............................................. starts with an ASCII “Z”, then an ID character, followedby the message data, a carriage return (CR = 0Dh), and aline feed (LF = 0Ah) See the following table............................................. the message checksum, same format as message .................................................... ASCII “end of text” character (ETX = 03h)
