Data message format
<SOH><SID><STX><TAB>xx<TAB>y<TAB>z<TAB><CRC16 %04d><ETX><CR><LF>
Name | Description |
---|---|
<SOH><SID><STX> |
Message header, where <SID>
identifies individual RSI51 units. For example, 1A . |
<TAB>xx<TAB>y<TAB>z<TAB> |
Message data:
|
<CRC16 %04d> |
Message checksum:
|
<ETX><CR><LF> |
Message trailer |
Data message characteristics
Property | Value |
---|---|
Default send interval | 10 s |
Polling command | <CR><SYN>*A<CR><ENQ><SID><CR> |
Example of data message
In the following example, 12 ... 48 VDC
voltage signal goes through terminal block 6, which gives a runway
light intensity value 16
. The voltage signal also goes through terminal
block 11, and the runway-in-use value 1
indicates
that runway 1 is active. This example does not include a checksum.
<SOH>1A<STX><TAB>16<TAB>1<TAB>0<TAB><ETX><CR><LF>
Starting from AviMet version 7.4, the message must include a CRC16 checksum. The following example shows the same message with the checksum.
<SOH>1A<STX><TAB>16<TAB>1<TAB>0<TAB>38B2<ETX><CR><LF>
To ensure compatibility with the older versions of AviMet and Midas IV, you can select between the standard message format and the extended format which includes the checksum. The extended format is enabled with a parameter.
With the correct message format, AviMet can parse the data and calculate the correct Runway Visual Range (RVR) value.