User's Guide _______________________________________________________________________
46 ___________________________________________________________________ M210470EN-B
Start measurement command (aM)
This command asks the device to make a measurement. The measured
data are not sent automatically and should be requested with a
separate Send data command
aD.
The host device is not allowed to send any commands to other devices
on the bus until the measurement is completed. When several devices
are connected to the same bus and simultaneous measurements from
the different devices are needed, Start concurrent measurement
aC
or
Start concurrent measurement with CRC
aCC
should be used, see the
next sections.
See examples on page 50.
Command format:
aMx!
where
a
=
Device address (default = 0)
M
=
Start measurement command
x
=
The desired sensor to make the measurement
1 = Wind
2 = Temperature, humidity, pressure
3 = Precipitation
5 = Supervisor
If x is left out, the query refers to composite message
with which the user can request data from several sensors
with just one command.
!
=
Command terminator
The response is sent in two parts:
The response part 1:
atttn<cr><lf>
The response part 2 (indicates that the data is ready to be requested):
a<cr><lf>
where
a
=
Device address
ttt
=
The time after which the measurement is completed
(seconds)
n
=
The number of the measured parameters available
(maximum number is 9)
