Garmin GTX 3X5 Series Installation Manual - page 125
190-01499-02
GTX 3X5 Transponder TSO Installation Manual
Rev. 4
Page A-4
SHADIN S FORMAT
SA012
SA (ASCII characters); 012 represents indicated air speed (knots)
SB345
SB (ASCII characters); 345 represents true air speed (knots)
SC678
SC (ASCII characters); 678 represents Mach speed (thousandths)
SD9012
SD (ASCII characters); sign; 9012 represents pressure altitude (tens of feet)
SE3456
SE (ASCII characters); sign; 3456 represents density altitude (tens of feet)
SF78
SF (ASCII characters); sign; 78 represents outside air temperature (Celsius)
SG90
SG (ASCII characters); sign; 90 represents true air temperature (Celsius)
SK901
SK (ASCII characters); sign; 901 represents vertical speed (tens of ft/minute)
SL234
SL (ASCII characters); 234 represents heading (degrees from north)
Sa1234
Sa (ASCII character); sign; 1234 represents barometric corrected altitude (tens of feet)
Sb56.78
Sb (ASCII character); 56.78 represents current barometric pressure setting (inches Hg)
S*901
S* (ASCII character); 901 represents checksum
Where:
start-transmit character (0x02)
carriage-return character (0x0D)
line-feed character (0x0A)
sign indicator (0x2B[+] or 0x2D[-])
end-transmit character (0x03)
NOTE
Checksum is calculated by adding each byte in the message (including all characters from
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).