190-01499-02
GTX 3X5 Transponder TSO Installation Manual
Rev. 4
Page A-4
SHADIN S FORMAT
<STX>
SA012<CR><LF>
SA (ASCII characters); 012 represents indicated air speed (knots)
SB345<CR><LF>
SB (ASCII characters); 345 represents true air speed (knots)
SC678<CR><LF>
SC (ASCII characters); 678 represents Mach speed (thousandths)
SD<+/->9012<CR><LF>
SD (ASCII characters); sign; 9012 represents pressure altitude (tens of feet)
SE<+/->3456<CR><LF>
SE (ASCII characters); sign; 3456 represents density altitude (tens of feet)
SF<+/->78<CR><LF>
SF (ASCII characters); sign; 78 represents outside air temperature (Celsius)
SG<+/->90<CR><LF>
SG (ASCII characters); sign; 90 represents true air temperature (Celsius)
SK<+/->901<CR><LF>
SK (ASCII characters); sign; 901 represents vertical speed (tens of ft/minute)
SL234<CR><LF>
SL (ASCII characters); 234 represents heading (degrees from north)
Sa<+/->1234<CR><LF>
Sa (ASCII character); sign; 1234 represents barometric corrected altitude (tens of feet)
Sb56.78<CR><LF>
Sb (ASCII character); 56.78 represents current barometric pressure setting (inches Hg)
S*901<CR><LF>
S* (ASCII character); 901 represents checksum
<ETX>
Where:
<STX>
start-transmit character (0x02)
<CR>
carriage-return character (0x0D)
<LF>
line-feed character (0x0A)
<+/->
sign indicator (0x2B[+] or 0x2D[-])
<ETX>
end-transmit character (0x03)
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).