Multiplexers controlled by data logger

For this configuration, SDI-12 is used to measure the vibrating-wire sensors. The vibrating-wire sensors are attached to multiplexers, which are controlled by the data logger.

SDI-12 communications

NOTE:

  1. When using SDI-12, multiplexers must be controlled by the data logger.

  2. SDI-12 is the only option available for non-Campbell Scientific data loggers.

If using SDI-12 communications, do the following:

  1. Access Device Configuration Utility to configure the AVW200 for SDI-12 communications. Go to the Deployment/Measurement tab in Device Configuration Utility and enter the SDI-12 address, multiplexer type, begin frequency, end frequency, and excitation (see Connecting to Device Configuration Utility and Measurement).

  2. Use a CABLE4CBL-L cable to connect the AVW200 to the multiplexers (see ).

    NOTE:

    SDI-12 uses CLK and RESET on the multiplexer instead of the CLK and RESET address on the AVW200.

  3. Connect the sensors to the multiplexers. Refer to the spread spectrum data radio/modem manual for more information: https://s.campbellsci.com/documents/us/manuals/rf401a-series.pdf .

  4. Use a CABLE4CBL-L cable to connect the multiplexers to the data logger (see Multiplexer to data logger power/control hookup (multiplexer controlled by data logger)).

  5. Use a CABLE3CBL-L cable to connect the C1 terminal on the AVW200 to a control port and ground on the data logger.

  6. Connect one end of the power cable to the 12V and G terminals on the AVW200 and the other end to the 12V and G terminals on the data logger or external power supply. Refer to Power and ground and Data logger wiring for a direct connection for more information.

  7. Program the data logger. Campbell Scientific CRBasic data loggers use the SDI12Recorder() instruction. The SDI12Recorder() instruction should only be run in the sequential mode for this configuration. See Programming for SDI-12 measurements, SDI-12 example.