Garmin GTX 3X5 Installation Manual page 124

SHADIN G FORMAT
<STX>
GA012<CR><LF>
GB345<CR><LF>
GC678<CR><LF>
GD<+/->9012<CR><LF> GD (ASCII characters); sign; 9012 represents pressure altitude (tens of feet)
GE<+/->3456<CR><LF> GE (ASCII characters); sign; 3456 represents density altitude (tens of feet)
GF<+/->78<CR><LF>
GG<+/->90<CR><LF>
GK<+/->901<CR><LF> GK (ASCII characters); sign; 901 represents vertical speed (tens of ft/minute)
GL234<CR><LF>
GP89012<CR><LF>
GR6789.0<CR><LF>
Ga<+/->1234<CR><LF> Ga (ASCII characters); sign; 12.34 represents barometric corrected altitude
Gb56.78<CR><LF>
G*901<CR><LF>
<ETX>
Where:
<STX>
<CR>
<LF>
<+/->
<ETX>
[1] Not available from Airdata Computer
NOTE
Checksum is calculated by adding each byte in the message (including all characters from
<STX> up to and including the error log/reason indicator), such that carries are
discarded to give a one byte result. The ASCII-coded decimal representation of that byte is
given, ranging from 0 (0x30, 0x30, 0x30) to 255 (0x32, 0x35, 0x35).
190-01499-02
Rev. 4
GA (ASCII characters); 012 represents indicated air speed (knots)
GB (ASCII characters); 345 represents true air speed (knots)
GC (ASCII characters); 678 represents Mach speed (thousandths)
GF (ASCII characters); sign; 78 represents outside air temperature (Celsius)
GG (ASCII characters); sign; 90 represents true air temperature (Celsius)
GL (ASCII characters); 234 represents heading (degrees from north)
GP (ASCII characters); 89012 represents fuel used, left (or Single) (tenths
gallons)
GR (ASCII characters); 6789.0 represents fuel remaining (gallons) [1]
(tens of feet)
Gb (ASCII characters); 56.78 represents current barometric pressure setting
(inches Hg)
G* (ASCII characters); 901 represents checksum
start-transmit character (0x02)
carriage-return character (0x0D)
line-feed character (0x0A)
sign indicator (0x2B[+] or 0x2D[-])
end-transmit character (0x03)
GTX 3X5 Transponder TSO Installation Manual
Page A-3