Users Manual

Operating Instructions Smart Weather Sensor
G. Lufft Mess- und Regeltechnik GmbH, Fellbach, Germany 149
19.8.1 Basic Interface Properties
• Baud rate configurable from 1200bps to 57600bps, character format 8 bits, no parity,
1 stop bit (8N1).
• Unit ID equal to UMB device ID, but limited to 98. 99 is the broadcast ID
• Data output on request or continuously (configurable)
• Commands and messages use strictly ASCII text mode
19.8.2 Message Format for Commands and Responses
Byte
0
'*'
Start Character
1,2
'01'
Destination ID
3,4
'00'
Source ID
5 ... n
Command Data (min. 2)
n+1, n+2
<CR><LF>
Termination Characters
The command data field always starts with the 2-character command identifier, optionally
followed by a parameter, starting with '='.
Currently implemented commands are
• P9 single measurement XDR format
• PP start continuous measurement XDR format
• PB single measurement PWSD format
• PC start continuous measurement PWSD format
• GW option: add MWD sentence (wind data) to XDR format
• MI continuous measurement interval
• J3 pressure mode (absolute air pressure / relative air pressure)
• JS pressure sensor elevation
• JW spot or average output of wind data
• BR baud rate
• ID unit ID
• NH message prefix
If the device receives an invalid command (missing start or termination character, invalid ID,
invalid structure etc.), it will not respond.
If a setting command contains an invalid parameter value, the device will not respond.
Setting commands must usually be preceded by the “Write Enable” command EW. This
command does not generate a response, and may be, different from other commands,
transmitted without message terminators (<CR><LF>). I.e. the write enable and the set
command may be concatenated without terminators between the commands.
Example:
0100EW*0100J3=1<CR><LF>
and
0100EW<CR><LF>*0100J3=1<CR><LF>
are both valid command sequences for setting the pressure mode.
Setting commands not requiring a preceding write enable are marked in the command
description.