SDI-12 Protocol Converters and Testers

Neon LoRa WAN SDI 12 Extender 3600
The 3600 Neon LoRa WAN SDI 12 Extender is an extender device which utilises the LoRa communication system as its method of providing an SDI 12 extender function between SDI 12 field sensors and a Neon Remote Logger. The 3600 provides a bridge between two SDI 12 devices, emulating a standard wire connection between SDI 12 devices. Some of the other functions on the remote 3600 LoRa WAN SDI12 Extender are separately addressable, such as analogue inputs and counter inputs. The 3600 Neon LoRa WAN SDI 12 Extender is programmed in the factory to perform the SDI 12 bridge function.

The 3600 is a useful accessory product to be used in any measurement station especially when the measuring instruments are located a few hundred metres away from the central Neon Remote Logger at the hub of the measurement station. Using this extender eliminates the need for long runs of wire, which may not be practical, especially in some river measurement stations. The system requires a pair of the 3600 Neon LoRa WAN SDI 12 Extenders to be used; the system does not work with only one of these units in isolation.

Protocol Converter Model 6543A
The model 6543A Protocol Converter converts Modbus to SDI-12 requests or converts HSIO data to Modbus data. This allows Unidata dataloggers and third-party SDI-12 sensors to be integrated into process control (PLC, SCADA) systems. Modbus data is in RTU format. Modbus communications are via RS232 or RS485.

Modbus to SDI-12 Conversion:
The model 6543A Protocol Converter acts as a Modbus slave on a Modbus RTU bus. On receipt of certain Modbus commands the Protocol Converter module initiates SDI-12 commands, awaits the response and returns the results as Modbus values. The data returned is selectable as either binary decimal values with a sign delimiter or an IEEE 32bit floating-point values.

Modbus to HSIO Conversion:
The 6543A Protocol Converter can also act as HSIO slave on the HSIO connection from a UNIDATA data logger or Starflow. On receipt of HSIO data the Protocol Converter module stores the HSIO data into memory. On receipt of certain Modbus commands, the Protocol Converter returns the requested memory values as Modbus values. The data returned is an exact representation of the HSIO value/s received.

SDI-12 Tester Model 6412A
SDI-12 Tester is a portable unit which simplifies the setup and fault finding of SDI-12 sensors in the field and on the laboratory bench. It allows sending a variety of commands enabling sensors to be configured and read. It also enables monitoring communications between a logger and sensors(s) on an SDI-12 bus.
The unit has the following functions: monitor bus, query address, acknowledge active, change address, send identification, start the measurement, send data, send extended command and cyclical measure & send data.
6412A SDI-12 tester has also been tested using the NR Systems SDI-12 verifier.

To find SDI-12 communication protocol specifications please visit: SDI-12 Support Group or view Unidata white paper: SDI-12 Serial Digital Interface Standard