SDI-12 communications
SDI-12 Serial Data Interface at 1200 baud. Communications protocol for transferring data between the data logger and SDI-12 compatible smart sensors. is a 1200 baud communications protocol that supports many smart sensors, probes and devices. The data logger supports SDI-12 communications through two modes — transparent mode and programmed mode (see SDI-12 ports for wiring terminal information).
Conflicts can occur when a control port pair is used for different instructions (TimerInput(), PulseCount(), SDI12Recorder(), WaitDigTrig()). For example, if C1 is used for SDI12Recorder(), C2 cannot be used for TimerInput(), PulseCount(), or WaitDigTrig().
Transparent mode facilitates sensor setup and troubleshooting. It allows commands to be manually issued and the full sensor response viewed. Transparent mode does not record data. See SDI-12 transparent mode for more information.
Programmed mode automates much of the SDI-12 protocol and provides for data recording. See SDI-12 programmed mode/recorder mode for more information.
CRBasic Campbell Scientific's BASIC-like programming language that supports analog and digital measurements, data processing and analysis routines, hardware control, and many communications protocols. SDI-12 instructions include:
SDI12Recorder()SDI12SensorSetup()SDI12SensorResponse()
See the CRBasic Editor help for detailed instruction information and program examples: 
The data logger uses SDI-12 version 1.4.