Garmin GNS 480 Installation Manual page 136

Appendix B - Serial Interface Specifications
B.2.1.1 Moving Map Data
Definitions of the Moving Map output data are included in Table B- 6 and Table B- 7. A sample output
message is included in Figure B-3.
The serial output messages are in the following format.
<STX><id><data><it><id><data><it>...<id><data><it><ETX>
<STX> ....................................................ASCII "start of text" character (1 byte, 02h)
<id> ........................................................item designator (1 byte, from following table)
<data> ....................................................item data (format listed in following table)
<it> .........................................................item terminator (1 byte, 0Dh)
<ETX> ...................................................ASCII "end of text" character (1 byte, 03h)
Table B- 6 - Moving Map ASCII Navigation Data
ID Data Format
A sddmmhh
B sdddmmhh
C ddd
D ddd
E ddddd
G sdddd
I dddd
K ddd[dd]
L dddd
Q sddd
T ---A-----
a eampht
B-8
Length Description
7 Present latitude
s =sign: N for north, S for south
dd = degrees
mm = minutes
hh = hundredths of minutes
8 Present longitude
s = sign: E for east, W for west
ddd = degrees
mm = minutes
hh = hundredths of minutes
3 Track (magnetic): ddd = degrees
3 Ground speed: ddd = knots
5 Distance to active waypoint: ddddd = nm x 10
5 Cross track error:
s = sign: R for right, L for left of course
dddd = distance off course, hundredths of nm
4 Desired track (magnetic):
dddd = degrees x 10
3 to 5 Active waypoint identifier:
ddd[dd] = ASCII waypoint identifier
4 Bearing to active waypoint (magnetic):
dddd = degrees x 10
4 Magnetic variation:
s = sign: E for east, W for west
ddd = degrees x 10
9 Warnings: The 4th character will be an "A" when the navigation
data is flagged, otherwise, all characters will be dashed. All other
navigation data will be dashed when it is flagged.
8
Annunciator Flags:
e = Approach Enabled { '-' (off) || 'O'(on) }
a = Approach Active { '-' (off) || 'O'(on) || 'B' (blink)}
m = Message
p = Parallel Track
h = Hold
t = From/To
560-0982-01 Rev A
{ '-' (off) || 'O'(on) || 'B' (blink)}
{ '-' (off) || 'O'(on) }
{ '-' (off) || 'O'(on) || 'B' (blink)}
{'–' (off) || 'T' (To) || 'F' (From)}
GNS 480 (CNX80) Installation Manual