Chapter 7 ___________________________________________________ Getting the data messages
VAISALA________________________________________________________________________ 57
where
x.xn
=
Measurement data from the transducer n
un
=
Units of the transducer n measurement, see the following
transducer table.
c--cn
=
transducer n id. The WXT510's address aXU,A is added
as a base number to the Tranducer #ID. The address is
changeable, see command aXU,A= [0...9/A...Z/a...z]
1
.
a,x.x.a,c--c
=
Transducer n
*
CRC delimiter
hh
=
A two character CRC for the response.
<cr><lf>
=
Response terminator
1
NMEA-format transmits only numbers as transducer ids. If the
WXT510 address is given as a letter, it will be shown as a number
(0...9, A=10,B=11, a=36, b=37 etc.).
The checksum to be typed in the query depends on the device
identifier characters and can be asked from the WXT510, see example
below.
Example
: Typing the command $--WIQ,XDRxxx<crlf> (xxx
arbitrary characters) the WXT510 responds
$WITXT,01,01,08,Use chksum 2D*72<crlf>
indicating that *2D is the correct checksum for the $--WIQ,XDR
command.
If there are several distinct measurements of the same parameter
(according to the transducer table below), they are assigned with
different transducer ids. E.g. minimum, average and maximum wind
speed are measurements of the same parameter (wind speed) so if all
three are configured to be shown in the XDR message, they get
transducer ids A, A+1 and A+2, respectively, where A is the WXT510
address aXU,A. The same applies for the wind direction.
Temperature, Tp internal temperature and heating temperature have
the same unit, thus they are assigned with transducer ids A, A+1 and
A+2, respectively. Accumulation, duration and intensity for rainfall
and hails are measurements of the same parameters so they get
transducer ids A for rainfall and A+1 for hails.
E.g. for a WXT510 with device address 0 the transducer ids of all the
measurement parameters are as follows:
Measurement transducer id
Wind direction min
0
Wind direction average
1
