Vaisala WXT520 - Manual (Page 90)

User’s Guide ______________________________________________________________________
88 __________________________________________________________________ M210906EN-C
Examples of aM, aC and aD
Commands
The device address is 0 in all examples.
Example 1:
Start a wind measurement and request the data (all six wind parameters
are enabled in the message):
0M1!00036<cr><lf> (measurement ready in 3 seconds and 6
parameters available)
0<cr><lf> (measurement completed)
0D0!0+339+018+030+0.1+0.1+0.1<cr><lf>
NOTE aD0 command can also be used to break the measurement in progress
started with commands aM, aMC, aC or aCC.
NOTE In SDI-12 v1.3 Continuous measurement mode (aXU,M=R) the
sensor makes measurements at configurable update intervals. The aD
command following the aM, aMC, aC or aCC command always
returns the latest updated data. Thus in aXU,M=R mode issuing
consecutive aD commands may result in different data strings if the
value(s) happen to be updated between the commands.
NOTE The parameter order in messages is as follows:
Wind (M1): Dn Dm Dx Sn Sm Sx
PTU (M2): Ta Tp Ua Pa
Rain (M3): Rc Rd Ri Hc Hd Hi Rp Hp
Supv (M5): Th Vh Vs Vr Id
Comp (M): Wind PTU Rain Supv (parameters in above order)
The order of the parameters is fixed, but you can exclude any
parameter from the list when configuring the transmitter.