Garmin Apollo GX50, Installation Manual

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Serial Interface Specifications
72 Apollo GX50/60/65 Installation Manual
GPSS S
ERIAL
O
UTPUT
The GPSS output message provides information to the appropriate autopilot for roll steering.
Baud Rate: .........................................9600
Data Bit:.............................................8 BITS
Stop Bit: .............................................1 BIT
Parity:.................................................None
Output Rate:.......................................Approx. 1-sec ±0.5 sec
Buffer length Normal:........................Approx. 32 bytes to ??? bytes
The Apollo GX Series will output serial data in the following format:
<STX><id><data><it><id><data><it>…<id><data><it><EXT>
where.
<STX> is the ASCII start of character (1 byte <0x02> )
<id> is the item designator (1 byte i.e. “B” )
<data> is the item data (see item format in following pages)
<it> is the item terminator (1 byte Cr <0x0d> )
<ETX> is the ASCII end of character (1 byte <0x03>)
Table 14 - Ascii Autopilot data
Id Item
Format
Len Item Description
C ddd 3
Track:
(magnetic); ddd=degrees
D ddd 3
ground speed: ddd=knots
E ddddd 5
distance to active waypoint: ddddd=nm * 10
L dddd 4
bearing to active waypoint:
(magnetic); dddd = degrees * 10
h sddd 4
Horizontal Command Signal:
s=sign: L = bank left. R = bank right. X = invalid data.
ddd = degrees * 10