Vaisala WMT52 - Manual (Page 81)

Chapter 7 __________________________________________________ Getting the Data Messages
VAISALA_______________________________________________________________________ 79
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 (measurement ready in 3 seconds and 6
parameters available)
0 (measurement completed)
0D0!0+339+018+030+0.1+0.1+0.1
= Response terminator
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
Supv (M5): Th Vh Vs Vr Id
Comp (M): Wind Supv (parameters in above order)
The parameters are in the same order as in the Setting Field tables in
chapter
Sensor and Data Message Settings on page 95 . The order of the
parameters is fixed, but you can exclude any parameter from the list
when configuring the sensor.