Air Data Computer Format - FreeFlight 2101 I/O Approach Plus Installation And Checkout Manual

NUMBER
B.5.4

Air Data Computer Format

The Air Data computer transmits once per second using the following parameters:
Air Data messages are accepted when the serial port is set to "ENCODER". A packet consists of a set of ASCII
message strings. The first character of each packet is an ASCII Start-of-Text (STX = 02H). The last character of each
packet will be an ASCII End-of-Text (ETX = 03H).
Each message string begins with one ASCII character to identify it as an Air Data message ("Z"). The second
character identifies which message it is. The rest of the string consists of one or more alphanumeric ASCII fields.
Each message field ends with a carriage return, line feed (CR = 0D0AH). All numeric fields are ASCII decimal, right
justified and zero filled. If the Air Data Computer cannot supply data in a particular field, the field is filled with dashes
("-" = 2DH). The table on the next page lists the valid message strings.
Revision E
May 31, 2006
BIT
BYTE #1 BYTE #2
0 FT/ALT CONV
1 CAL TAS
2 HOLD KT
3 NO IAS
4 Vno UPATI
5 Vne DOWNATI
6 APP M
MACH
7 YES
decimal pt
Indicator Byte Table
Baud:
Parity:
Start Bit:
Data Bits:
Stop Bit:
Update Rate:
FreeFlight 2101 I/O Approach Plus GPS Navigation System
BYTE #3 BYTE #4
FLAP Mb
In Hg
GEAR
decimal pt
FPM
TAT
C
LGT
temp - sign
In Hg
9600
None
1
8
1
1 msg/sec
-
-
-
-
-
-
Page B-5