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SDI12 basic command set

The SDI12 command set includes the basic command set as specified by the standard (i.e. V1.1, V1.2, V1.3, V1.4, etc) as well as extended commands which may be included by the manufacturers to add special functionality which is not part of the standard.  A common use of the extended commands are to include calibration information.  This page reviews the basic command set, relative to the version that it was included in, as well as an introduction of the extended commands

SDI12 Basic Command Set

NameCommandResponseNotes
Break (wake up)-Nonev1.0. To wake from sleep
Acknowledge Activea!av1.0. Testing
Send IdentificationaI!allccccccccmmmmmmvvvxxx...xxv1.0. Check if the right sensor is connected
Change AddressaAb!bv1.2. Change sensor address
Address Query?!av1.2. Who is connected? Only works for one sensor
Start MeasurementaM!atttnv1.0.
Start Measurement and Request CRCaMC!atttnv1.3.
Send DataaD0!
....
aD9!
a or av1.0.
Additional MeasurementsaM1!
...
aM9!
atttnv1.0.
Additional Measurements with CRCaMC1!
...
aMC9!
atttnv1.3.
Start VerificationaV1atttnv1.0.
Start Concurrent MeasurementaC!atttnv1.2.
Start Concurrent Measurement with CRCaCC!atttnv1.3.
Additional Concurrent MeasurementsaC1!
...
aC9!
atttnv1.2.
Additional Concurrent Measurements with CRCaCC1!
...
aCC9!
atttnv1.3.
Continuous MeasurementsaR0!
...
aR9!
av1.2.
Continuous Measurements with CRCaRC0!
...
aRC9!
av1.3.
High Volume CommandsaHA! (ASCII)
aHB! (Binary)
atttnnnv1.4. Allows up to 999 parameters to be returned from a sensor
Metadata Commands. Add I to most measurement commandsaIM!atttn
a,field1,field2,field3;
v1.4. Provides meta data information about the measurement, ie: field1 may be PR, field2 may be mm, field 3 may be precipitation rate per day

 

Extended Command Set

NameCommandResponseUsed by
Store one calibrationaXSETVAR[m,p]=VAL!aXACKVegetronix
Retrieve string of the last erroraXER!aXER BAD COMMANDVegetronix
Set sensor warm up timeaXW[ms]!aXACKVegetronix

Version History

You can view and download the SDI-12.org archives at http://www.sdi-12.org/archives.php.  The table above identifies the standard at which the basic command was introduced

 

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  1. SDI-12 Sensor Identification | SDI12 - May 29, 2017

    […]  This was introduced in Version 1.2 of the standard as a basic command, for more details refer to www.sdi12.com/sdi12-basic-command-set/.  An example of this […]

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