Gtn Rs-232 Fuel/Air Data Input Format; Electrical Interface; Shadin Altitude Sentence; Icarus Altitude Sentence - Garmin GTN 725 Installation Manual

B.2 GTN RS-232 Fuel/Air Data Input Format
B.2.1 Electrical Interface
The input signals are compatible with RS-232C. Data is input at 9600 baud with a word length of 8 bits,
one stop bit, and no parity. One message is received per second.
B.2.2 Shadin Altitude Sentence
The Garmin GTN is capable of receiving the following 17-byte message from Shadin Altitude Encoders,
Altitude Serializers, and Altitude Converters:
Where:
RMS ASCII characters
<sp> space (0x20)
<+/-> sign indicator (0x2b["+"] or 0x2d["-"])
12345 altitude in feet
T ASCII character
<+/-> sign indicator
12 sensor temperature
ul checksum of bytes 1 through 14 in hex ASCII (i.e., "FA")
<CR> carriage return (0x0d)
Note: Checksum is calculated by adding each byte in the message (1 through 14).
B.2.3 Icarus Altitude Sentence
The Garmin GTN is capable of receiving the following 10-byte message from the Icarus Altitude
Serializer:
ALT<sp>12345<CR>
Where:
ALT ASCII characters
<sp> space (0x20)
12345 altitude in feet
<CR> carriage return (0x0d)
GTN 725/750 TSO Installation Manual
190-01007-02
RMS<sp><+/->12345T<+/->12ul<CR>
Page B-5
Rev. A