Rs-232c ar-nav data format, Notes on the ar-nav sentence – BendixKing SKYMAP IIIC User Manual
Page 140

SERIAL DATA OUTPUT SENTENCES
RS-232C AR-NAV Data Format
The serial format is 9600 baud 8 data bits, 1 stop bit, no parity. A Type 1 sentence is only
sent every two seconds. Each line of data is followed by a carriage return (CR) and a line
feed (LF) character except the STX and ETX lines.
Header Data
Description.
STX
Hex
02
z
aaaaaCRLF
GPS altitude in feet.
A
s dd mmhhCRLF
Latitude where s = N or S, dd = degrees, mm = minutes, hh =
hundredths of minutes.
B
s ddd mmhhCRLF
Longitude designated as above.
C
dddCRLF
Magnetic track in whole degrees.
D
sssCRLF
Groundspeed in knots.
E
dddddCRLF
Distance to waypoint in 1/10ths of nm.
G
snnnnCRLF
Cross track error where s = L or R (of track) and nnnn = error in
100ths of an nm.
I
ddddCRLF
Desired magnetic track in 10ths of a degree. i.e. BRG to
waypoint if you were on track.
K
cccccCRLF
Destination waypoint name. Dashes sent after name if shorter
than 5 characters.
L
ddddCRLF
Actual magnetic bearing to WPT (in 1/10ths of a degree).
Q
sdddCRLF
Variation. s= E or W. ddd = 1/10ths degrees.
S
----eCRLF
e = NAV flag. - = NAV valid, N = NAV not valid.
T
---------CRLF
Indicates end of sentence type 1.
ETX
Hex
03.
Notes on the AR-NAV sentence.
If the unit is not in NAV mode or does not have a fix, dashes (---) will be sent in fields E, G,
I, K, L. Part e of field S will be set to N.
If the unit does not have a fix, dashes will be sent in the latitude, longitude, track and
ground speed fields.
If the variation value is greater than 99.9°, a fourth character will be sent in the Q field (i.e.
sddddCRLF).
A
P
P
E
N
D
IC
E
S
Rev 9 Jul 2006
F-3
Skymap/Tracker IIIC Pilot's Guide