Garmin GNS 480 Installation Manaul page 146

Appendix B - Serial Interface Specifications
ID Data Format
c vDddd
l dddddd
(lower case L)
p sdddd
v vDddd
h sddd
w See Table B-7
Byte Data Format
1 w
2-3 dd
4 xiannnnn
5-9 ddddd
10 sddddddd
11 xxmmmmmm
12 xhhhhhhh
13 sxxxxxxx
14 dddddddd
15 xxmmmmmm
16 xhhhhhhh
17 nnnnnnnn
18 nnnnnnnn
19 <CR>
B-10
Table B-6. Moving Map ASCII Navigation Data
Length Description
7 CDI:
v = NAV Flag { '-' Flagged || 'v' Valid }
D = Needle { 'C' Center || 'L' Left || 'R' Right }
ddd = Deflection Value ASCII (000 – 100)
6 Distance to Destination:
dddddd = nm * 10
7 s = ± dddd = {0000 - 5999}
Pressure Altitude (-1500 to +5999 tens of feet +/- sea level).
Field is dashed when invalid "-----".
7 VDI:
v = VDI Flag { '-' Flagged || 'v' Valid }
D = Needle { 'C' Center || 'U' Up || 'D' Down }
ddd = Deflection Value ASCII (000 – 120)
4
Horizontal Command Signal:
s=sign: L = bank left. R = bank right. X = invalid data.
ddd = degrees * 10
18 Moving Map Binary Route Data
Table B-7. Moving Map Binary Route Data
Description
Item designator
Current waypoint number in ASCII (01h to 20h)
Sequence number
x = undefined
i = 1 if last waypoint
a = 1 if active waypoint
nnnnn = unsigned binary waypoint number
ASCII waypoint identifier
Waypoint latitude - packed, unsigned binary
s = sign: 0 for north, 1 for south
ddddddd = degrees
mmmmmm = minutes
hhhhhhh = hundredths of minutes
x = undefined
Waypoint longitude
s = sign: 0 for east, 1 for west
dddddddd = degrees
mmmmmm = minutes
hhhhhhh = hundredths of minutes
x = undefined
Magnetic variation at waypoint
LS byte (msbit...lsbit)
MS byte (msbit...lsbit)
Two's complement binary in sixteenths of degrees, easterly variation is
positive.
ASCII carriage return (0Dh)
560-0982-01 Rev L GNS 480 (CNX80) Installation Manual