Page B-6
GTN 625/635/650 TSO Installation Manual
Rev. C
190-01004-02
B.2.4 Shadin Fuel Flow Sentence
The Garmin GTN is capable of receiving the following 55-byte message from the Shadin Fuel Flow
Indicator:
<STX>K0543.2<sp>0100.0<sp>0040.0<sp>0060.0<sp>0123.4<sp>0045.4<sp>0078.0<sp>123<ETX>
Where:
<STX>
start-transmit character (0x02)
K
units designation (i.e., Gallons, Liters, Kilograms, B[pounds])
0543.2
total fuel remaining (i.e., ASCII-coded decimal format: 0x30, 0x35, 0x34, 0x33, 0x2e,
0x32)
<sp>
space (0x20)
0100.0
fuel flow rate, total (formatted as for total fuel remaining)
0040.0
fuel flow rate, engine one (or asterisks["
"], in the case of single engine aircraft)
0060.0
fuel flow rate, engine two (asterisks, in the case of single engine aircraft)
0123.4
fuel used, total
0045.4
fuel used, engine one (asterisks, in the case of single engine aircraft)
0078.0
fuel used, engine two (asterisks, in the case of single engine aircraft)
123
checksum (of bytes 2 through 51)
<ETX>
end-transmit character (0x03)
Note
: Checksum is calculated by adding each byte in the message (2 through 51), 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).
B.2.5 ARNAV/EI Fuel Flow Sentence
The Garmin GTN is capable of receiving the following 13-byte message from the ARNAV or Electronics
International (―EI‖) Fuel Flow Indicators:
<STX>G0245100550<ETX>
Where:
<STX>
start-transmit character (0x02 hex)
G
units designation (i.e., Gallons, Imperial gallons, Liters, Kilograms, B[pounds])
0245
total fuel remaining in reverse order (i.e., ASCII-coded decimal format: 0x30, 0x32,
0x34, 0x35)
1
fuel remaining checksum (modulo 10 sum of four "total fuel remaining" digits)
0055
total fuel flow rate in reverse order
0
fuel flow checksum
<ETX>
end-transmit character (0x03)
Note
: Fuel remaining and fuel flow are [ 10] when units designation is gallons or imperial gallons. For
example, 0245 gallons indicates 542 gallons; 0245 liters indicates 5420 liters. Checksum is the modulo 10
sum of the four fuel flow decimal digits, converted to an ASCII numerical character (e.g., checksum for
"5678" would be ASCII "6").
