Table 22-2: SDI-12 probe connections
Wire function Data logger connection
SDI-12 signal C1, C2
Shield G
Power 12V
Power ground G
System operators can manually interrogate and enter settings in probes, connected to the data 
logger, 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 
video:https://www.campbellsci.com/videos/sdi12-sensors-transparent-mode .
To enter the SDI-12 transparent mode, enter the data logger support software terminal emulator:
1.  Press Enter until the data logger responds with the prompt CR300 series>. 
2.  Type SDI12 at the prompt and press Enter.
3.  In response, the query Select SDI12 Port is presented with a list of available ports.  
Enter the port number assigned to the terminal to which the SDI-12 sensor is connected, 
and press Enter.  For example, 1 is entered for terminal C1.
22. Tips and troubleshooting182