Garmin GTX 3X5 Series Installation Manual - page 123

190-01499-02

GTX 3X5 Transponder TSO Installation Manual

Rev. 4

Page A-2

A.1.4 Airdata Format 1 Sentence

The GTX 3X5 is capable of receiving the following message strings from the air data computer. 

SHADIN Z FORMAT

ZA012

ZA (ASCII characters); 012 represents indicated air speed (knots)

ZB345

ZB (ASCII characters); 345 represents true air speed (knots)

ZC678

ZC (ASCII characters); 678 represents mach speed (thousandths)

ZD9012 ZD (ASCII characters); sign; 9012 represents pressure altitude (tens of feet)

ZE3456 ZE (ASCII characters); sign; 3456 represents density altitude (tens of feet)

ZF78

ZF (ASCII characters); sign; 78 represents outside air temperature (Celsius)

ZG90

ZG (ASCII characters); sign; 90 represents true air temperature (Celsius)

ZL234

ZL (ASCII characters); 234 represents heading (degrees from north)

ZQ345

ZQ (ASCII characters); 345 represents error log/reason indicator

ZR678

ZR (ASCII characters); 678 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 

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).