Serial altitude formats, Format 1, Format 2 – Dynon Avionics FlightDEK-D180 Installation Guide User Manual
Page 47: Format 3, Format 4

Instrument
Installation
FlightDEK-D180 Installation Guide
4-9
system is displayed, push the following sequence of buttons: MORE > SETUP > MORE >
ALTENC. When in the Altitude Encoder Setup menu, you can toggle the resolution of the output
between 10 and 100 feet; this accommodates some transponders which can input and display
altitude in 10 foot increments. In this menu, you can also select between the four different output
formats, which are described below.
Dynon’s supplied EFIS harness has a serial altitude encoder cable which consists of 2
conductors, surrounded by a metal shield and white insulation. Dynon has shipped harnesses
with different colors for Encoder serial transmit line. Determine your connections using the table
above. Connect the Encoder serial transmit to your transponder’s serial input or to Dynon’s
Serial-to-Gray Code Converter as described in the Encoder Serial-to-Gray Code Converter
Installation section on page 9-31 in the Appendix.
SERIAL ALTITUDE FORMATS
There are four formats used by serial transponders. Choose the correct format for your
transponder in the ALTENC menu, using the FRMAT button.
Format 1
Used By
Dynon Encoder Serial-to-Parallel Converter, Garmin AT
(formerly UPS Aviation Technologies)
Baud rate
1200
Format
#AL, space, +/-sign, five altitude bytes, T+25, checksum,
carriage return
Example message
#AL +05200T+25D7[CR]
Format 2
Used By
Magellan
Baud rate
1200
Format
$MGL, +/- sign, five altitude digits, T+25, checksum, carriage
return
Example message
$MGL+05200T+25E3[CR]
Format 3
Used By
Northstar, Garmin
Baud rate
2400
Format
ALT, space, five altitude bytes, carriage return
Example message
ALT 05200[CR]
Format 4
Used By
Garmin GTX330 (set on Icarus input), Garmin GTX327 (set
on Icarus input), Garmin GTX328, Icarus, Trimble
Baud rate
9600
Format
ALT, space, five altitude bytes, carriage return
Example message
ALT 05200[CR]