Use this command to request the measured data
from the device.
| Start measurement command
indicates the number of parameters available. The number of the parameters that can be
included in a single message depends on the number of characters in the data fields. If not
all the parameters are retrieved in a single response message, repeat the Send data commands
until all the data is obtained. |
Command format:
aDx!
| a |
Device address |
| D |
Send data command |
| x |
The order of consecutive Send data commands. Make sure the first Send
data command is addressed with x=0. If all the parameters are not retrieved, send the
next Send data command with x=1 and so on. The maximum value for x is 9. |
| ! |
Command terminator |
Response:
a+<data fields><cr><lf>
| a |
Device address |
| <data fields> |
The measured parameters in selected units, separated with '+' marks
(or - marks in case of negative parameter values). |
| <cr><lf> |
Response terminator |
|
aD0 command can also be used to break the measurement in
progress started with commands aM, aMC, aC, or aCC. |
| 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 can result in different data strings if the
values are updated between the commands. |