4 SDI-12
SDI-12 is a standard for interfacing data recorders with microprocessor-based sensors. SDI-12 stands for
serial/digital interface at 1200 baud. It can connect multiple sensors with a single data recorder on one cable. It
supports up to 60 meter cable between a sensor and a data logger.
The SDI-12 standard is prepared by
SDI-12 Support Group
(Technical Committee)
165 East 500 South
River Heights, Utah
435-752-4200
435-752-1691 (FAX)
http://www.sdi-12.org
The latest standard is version V1.3 which dates from July 18th, 2005. The standard is available on the website of
the SDI-12 Support Group.
More information on SDI-12 is presented in chapter 3.
5 Supported SDI-12 Commands
Following standard SDI-12 commands are supported:
Start Measurement aM!
Start Measurement and Request CRC aMC!
Additional Measurements aM1! …aM9!
Additional Measurements and Request CRC aMC1 ! ... aMC9!
Start Concurrent Measurement aC!
Start Concurrent Measurement and Request CRC aCC!
Additional Concurrent Measurements aC1! …aC9!
Additional Concurrent Measurements and Request CRC aCC1 ! ... aCC9!
Send Data aD0! …aD9!
Example –controlling the soil moimoisture/temperature Sensor:
https://www.sdi-12products.com/collections/sensors/products/sdi-12-soil-moisture-temperature-probe-tbsmp02
