SDI-12

SDI-12 (Serial Digital Interface at 1200 baud) is an asynchronous serial communications protocol for intelligent sensors that monitor environment data. These instruments are typically low-power (12 volts), are used at remote locations, and usually communicate with a data logger or other data acquisition device. The protocol follows a master-slave configuration whereby a data logger (SDI-12 recorder) requests data from the intelligent sensors (SDI-12 sensors), each identified with a unique address. SDI-12 (Serial Digital Interface at 1200 baud) is an asynchronous serial communications protocol for intelligent sensors that monitor environment data. These instruments are typically low-power (12 volts), are used at remote locations, and usually communicate with a data logger or other data acquisition device. The protocol follows a master-slave configuration whereby a data logger (SDI-12 recorder) requests data from the intelligent sensors (SDI-12 sensors), each identified with a unique address. The first version of SDI-12 was released in 1988. It was designed by a coalition which included the U.S. Geological Survey's Hydrologic Instrumentation Facility (HIF) and a group of private companies. The SDI-12 Specification is maintained by a non-profit corporation called the SDI-12 Support Group. The most recent upgrade (Version 1.4) was made in May, 2017.