Appendix B - Serial Interface Specifications
B-4
560-0982-01 Rev A
GNS 480 (CNX80) Installation Manual
B.1.2 Fuel/Air Data Computer Input
The fuel/air data input is used to input fuel flow and airdata computer information from the fuel/air data
computer. Both the Shadin “S” format and Shadin “Z” format data are automatically accepted.
B.1.2.1 “S” Data Format
The format of the fuel/air data computer input is as follows, which conforms to the Shadin “S” format
serial message. Definition of the input message data that the GNS 480 uses is included in Table B- 3. A
sample input message is illustrated in Figure B- 2.
Baud rate: ...............................................9600
Data bits: ................................................8
Stop bits: ................................................1
Parity: .....................................................none
Expected input rate: ...............................approx. 1 second
Message length: ......................................variable (512 character max.)
The serial input message string is expected in the following format.
<STX><message><message> ... <message><chksum><ETX>
<STX>.....................................................ASCII “start of text” character (STX = 02h)
<message>...............................................starts with an ASCII “S”, then an ID character, followed
by the message data, a carriage return (CR = 0Dh), and a
line feed (LF = 0Ah) See the following table. s = a sign
indicator (-,+,E,W). d = a decimal digit (0-9)
<checksum> ............................................the message checksum, same format as message
<ETX> ....................................................ASCII “end of text” character (ETX = 03h)
Table B- 3 - Fuel/Air Data Message Data (S Format)
Item
Desig
Message
Format
Message
Mnemonic
Field
Width
Message Description
SA
ddd
IAS
7
Indicated Air Speed in knots
SB
ddd
TAS
7
True Air Speed in knots
SC
ddd
MACH
7
Mach Speed in thousandths
SD
sdddd
PALT
9
Pressure Altitude in tens of feet, +/- sea level
SE
sdddd
DALT
9
Density Altitude in tens of feet, +/- sea level
SF
sdd
OAT
7
Outside Air Temp - or “Total”, in degrees Celsius
SG
sdd
TAT
7
True Air Temp - or “Static”, in degrees Celsius
SH
ddd
WDIR
7
Wind Direction, 0 to 359 degrees from true north
SI
ddd
WSPD
7
Wind Speed in knots
SJ
sdd
TURN
7
Rate of Turn in +/- degrees/second, + is right, - is left
SK
sddd
VSPD
8
Vertical speed in tens of feet/minute
SL
ddd
HEAD
7
Heading, 0 to 359 degrees from true north
SM
dddd
RFF
8
Right Engine Fuel Flow in tenths of gallons/hour
SN
ddddd
RFU
9
Right Engine Fuel Used in tenths of gallons
SO
dddd
LFF
8
Left Engine Fuel Flow in tenths of gallons/hour
SP
ddddd
LFU
9
Left Engine Fuel Used in tenths of gallons
SQ
ddd
ERR
7
Error Log / Reason Indicator: 001 = temp sensor error; 000
= no errors
Summary of Contents for GNS 480
Page 1: ...GNS 480 CNX80 Color GPS Nav Com Installation Manual September 2004 560 0982 01 Rev A...
Page 10: ...Table of Contents viii 560 0982 01 Rev A GNS 480 CNX80 Installation Manual NOTES...
Page 30: ...General Information 1 20 560 0982 01 Rev A GNS 480 CNX80 Installation Manual NOTES...
Page 126: ...Periodic Maintenance 6 2 560 0982 01 Rev A GNS 480 CNX80 Installation Manual NOTES...
Page 150: ...Appendix D Interconnect Diagrams D 2 560 0982 01 Rev A GNS 480 CNX80 Installation Manual NOTES...
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