In-Situ Aqua TROLL 400 Modbus and SDI-12 Reference Guide - Manual (Page 15)

Name Command Response
Start Measurement
Start Measurement CRC
Send Data
Additional Data
aM!
aMC!
aD0!
aD1!...aD9! a004n<CR><LF>
n parameters will be available for reading by the Send
Data command within 4 seconds. A service request
(a<CR><LF>) will be sent when the parameters are
ready. The number of parameters returned is
determined by the SDI-12 configuration file. The default
value for n is 7. The default parameters are:
1: DO concentration in mg/L
2: DO percent saturation
3: Temperature in
°C
4: Specific conductivity in uS/cm
5: Depth in feet
6: pH
7: ORP in millivolts
If the device is configured to output more than 9
parameters, only the first 9 parameters can be
measured by this command.
a<values><CR><LF> or
a<values><CRC><CR><LF>
The number and type of parameters returned is
determined by the SDI-12 configuration file. At most 3
parameters are returned in a Send Data command. If
more than 3 parameters are available, they are
returned using the additional data command.
a<values><CR><LF> or
a<values><CRC><CR><LF>
At most 3 parameters are returned per additional data
request.
Additional Measurements
Additional with CRC
Send Data
Additional Data
aM1! … aM9!
aMC1!… aMC9!
aD0!
aD1! … aD9! a0000<CR><LF>
No additional measurements shall be started by the
device.
a<CR><LF> or
a<CRC><CR><LF>
No values are returned after an Additional
Measurement command.
15