Chapter 7 ___________________________________________________ Getting the data messages
VAISALA________________________________________________________________________ 55
where
MWV
=
Wind speed and direction response identifier
x.x
=
Wind direction value
R
=
Wind direction unit (R=relative)
y.y
=
Wind speed value
M
=
Wind speed unit (m/s)
A
=
Data status: A= valid, V=Invalid
*
checksum delimiter
hh
=
A two character checksum for the response.
<cr><lf>
=
Response terminator
1
Wind direction is given in relation to the devices north-south axis.An
offset value to the measured direction can be set, see Chapter 8,
section
Wind sensor
.
The checksum to be typed in the query depends on the device
identifier characters. The correct checksum can be asked from the
WXT510 by typing any three characters after the $--WIQ,MWV
command.
Example
: Typing the command $--WIQ,MWVxxx<crlf> (xxx
arbitrary characters) the WXT510 responds
$WITXT,01,01,08,Use chksum 2F*72<crlf>
which tells that *2F is the correct checksum for the $--WIQ,MWV
command.
Example of the MWV Query:
$--WIQ,MWV*2F<crlf>
$WIMWV,282,R,0.1,M,A*37<crlf>
(Wind angle 282 degrees, Wind speed 0.1 m/s)