SDI-12 Command Summary:
Acclima SDI-12 sensors implement commands that comply with versions 1.0, 1.1, 1.2, 1.3 and 1.4
of the SDI-12 specifications. All commands required for full compliance of the version 1.4
specifications are implemented in the TDR sensors. However, the ‘additional measurements’
commands in the SDI-12 specification are meaningless to the Acclima SDI-12 sensors, since the
permittivity, moisture, conductivity, and temperature measurements are all required and all made
with every single measurement. Hence the response for all of these additional measurements
commands is
“a<CR><LF>”
as required by the SDI-12 specification. The sensor ignores
unimplemented commands outside those required by the SDI-12 specification. There is no response
to them.
Additional ‘Extended Commands’ that are not enumerated here, are in
corporated by Acclima for
digitized waveform dumps and factory calibration settings and readings.
Command Reference:
The table below documents all commands supported by the SDI-12 sensor in alphabetical order:
Command
Function
Sensor Response
?!
Address Query
a Note: only one device can be connected to the SDI-12 port
when this command is used. a<CR><LF>
a!
Acknowledge
Active
a a<CR><LF>
aAb!
Change Address
b b<CR><LF>
aC!
aCC!
Start Concurrent
Measurement
Start Concurrent
Measurement-
Request CRC
a00105<CR><LF>
Measurement takes 1 seconds. 5 values are returned
aC1!
.
aC9!
Start Additional
Concurrent
Measurement
a00000<CR><LF>
No data to be provided
