Garmin Apollo CNX80, Installation Manual

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Appendix B - Serial Interface Specifications
Apollo CNX80 Installation Manual 560-0982-00 Rev D B-9
B.2.1.2 Binary Nearest List Data
The nearest waypoint lists are sent one waypoint per data transmission set. The lists are sent in the
following order:
•
LFAC
•
VOR
•
NDB
•
INT
•
User
There is a maximum of twenty waypoints per type. The waypoints are a maximum of 600 nm from the
current position. The waypoints are order by distance from current position nearest to farthest. The
maximum time to send all lists is 100 seconds. Each list is updated just prior to the first waypoint in the list
being sent. If a list is empty a shorter record will be sent with the List Item Number set to 0xFF.
Table B- 8 - Nearest Waypoint List Data
Byte Format Description
1 Z ‘Z’
Item Designator
2 sddddddd
List Item Number:
Packed, unsigned binary values
s = 1 End of list, 0 all other
ddddddd = 1 – 20 list waypoint index
sddddddd = 0xFF List Type is EMPTY
(BYTE 4 terminate Item)
3 t
Waypoint Type
:
t = {a (airport) || v (VOR) || n (NDB) || i (INT) || u (USER)}
4 Cr ‘\r’
Item Terminator
<0x0d>
(ONLY IF BYTE 2 = OxFF)
4-8 ddddd
ASCII Waypoint Identifier
9
10
11 sddddddd
xxmmmmmm
xhhhhhhh
Latitude of waypoint.
Packed, unsigned binary values for degrees, minutes
and hundredths of minutes.
s = 0 North latitude, 1 South latitude
x = undefined
ddddddd = Latitude degrees
mmmmmm = Latitude minutes
hhhhhhh = Latitude hundredths of minutes
12
13
14
15 sxxxxxxx
dddddddd
xxmmmmmm
xhhhhhhh
Longitude of waypoint.
Packed, unsigned binary values for degrees, minutes
and hundredths of minutes.
s = 0 East longitude, 1 West longitude
x = undefined
ddddddd = Longitude degrees
mmmmmm = Longitude minutes
hhhhhhh = Longitude hundredths of minutes
16 Cr
‘\r’
Item Terminator
<0x0d>