know the data logger PakBus address. The PakBus address is changed using Device
Configuration Utility, data logger Settings Editor, or PakBus Graph software.
15.6 SDI-12 communications
SDI-12 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
(p. 12) for wiring terminal information).
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
(p. 130) for more information.
Programmed mode automates much of the SDI-12 protocol and provides for data recording. See
SDI-12 programmed mode/recorder mode
(p. 100) for more information.
CRBasic SDI-12 instructions include:
l
SDI12Recorder()
l
SDI12SensorSetup()
l
SDI12SensorResponse()
l
SDI12Watch()
See the CRBasic Editor help for detailed instruction information and program examples:
https://help.campbellsci.com/crbasic/cr300/.
The data logger uses SDI-12 version 1.4.
15.6.1 SDI-12 transparent mode
System operators can manually interrogate and enter settings in probes using transparent mode.
Transparent mode is useful in troubleshooting SDI-12 systems because it allows direct
communications with probes.
Transparent mode may need to wait for commands issued by the programmed mode to finish
before sending responses. While in transparent mode, the data logger programs may not
execute. Data logger security may need to be unlocked before transparent mode can be
activated.
Transparent mode is entered while the computer is communicating with the data logger through
a terminal emulator program such as through Device Configuration Utility or other data logger
support software. Keyboard displays cannot be used. For how-to instructions for communicating
directly with an SDI-12 sensor using a terminal emulator, watch this
15. Communications protocols
98