Garmin GNC 420AW, Installation Manual

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400W Series Installation Manual Page E-1
190-00356-02 Rev. G
Appendix E 400W SERIES RS-232 FUEL/AIR DATA INPUT FORMAT
E.1 Electrical Interface
The input signals are compatible with RS-232C. Data input is at 9600 baud with a word length of 8 bits,
one stop bit, and no parity. One message is received per second.
E.2 Shadin Altitude Sentence
The Garmin 400W Series units are capable of receiving the following 17-byte message from Shadin
Altitude Encoders, Altitude Serializers, and Altitude Converters:
RMS<sp><+/->12345T<+/->12ul<CR>
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).
E.3 Icarus Altitude Sentence
The Garmin 400W Series units are 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)