Modbus & SDI-12


Below is a list of frequently asked questions for the Diver-MOD. If you have a question that is not listed here please contact our technical support team.


What are the options to power the Diver-MOD?

The power requirements are 5 to 12 VDC. The power supply needs to be able to deliver at least effective 20 mA/peak 50 mA.

Do I need a Baro-Diver to perform the compensation?

The integrated baro sensor can be used to compensate the Diver data for barometric fluctuations. The accuracy of the baro sensor is 2 cmH2O over a temperature range of 0 to 50 °C.

Can the Diver-MOD be submerged safely?

The International Protection Marking of the Diver-MOD is IP65. This means that the Diver-MOD is dust tight and protected against water jets.

Does the Diver have to be started?

The Diver-MOD can work with both a started Diver and non-started Diver. Moreover, the Diver can be started and stopped using Modbus communication.

How can I compensate my data?

The Diver-MOD is equipped with a barometric pressure sensor of which data can be collected using the Modbus system. The barometric compensation must be done by the back-end software/ supervisory computer.

When can the Diver-MOD be used?

The Diver-MOD can be used to integrate the Diver into industrial Modbus networks.

What are the system requirements for the Diver-MOD?

The Diver-MOD requires the Modbus RTU interface (Modbus Application Protocol Specification V1.1b3).

The power requirements are 4.75 to 13.5 VDC. The power supply needs to be able to deliver at effective 20 mA/peak 50 mA.

What is the warm-up time of the Diver-MOD?

After powering on the Diver-MOD the baro-sensor can provide a measurement after 100 ms and the communication with the Diver can start after 100 ms.

What is the maximum cable length from the Diver-MOD to the Diver?

The maximum length of the cable between the Diver and the Diver-MOD is 500 meter (1,640 ft).

What is the maximum cable length from the Diver-MOD to the supervisory computer (master RS485)?

The maximum length of cable between the Diver-MOD and the supervisory computer is 1,000 meter @ 9,600bps, see the RS485 specifications for more details.

How many Diver-MODs can be connected to a Modbus network?

Up to 8 Diver-MODs can be used in a Modbus network.

What is Modbus?

Modbus Protocol is a messaging structure developed by Modicon in 1979. It is used to establish master-slave/client-server communication between intelligent devices. It is a de facto standard, truly open and the most widely used network protocol in the industrial manufacturing environment. It has been implemented by hundreds of vendors on thousands of different devices to transfer discrete/analog I/O and register data between control devices. See also

Can I read the Diver memory with the Diver-MOD?

Yes, you can read the Diver memory with the Diver-MOD.

Can I read compensated data with the Diver-MOD?

The Diver-MOD allows you to read a real-time compensated value. If you read the Diver memory you will need a barometric data source to compensate the Diver data.

If I read the Diver memory with the Diver-MOD, what is then the format of the data?

See the Diver-MOD manual for detailed instructions how to download data from a Diver using Modbus.

Can I import Diver data read by the Diver-MOD in Diver-Office?

Data generated by a Modbus system cannot be imported by Diver-Office.

Can I use the Diver-MOD over TCP/IP??

The Diver-MOD can only be used over asynchronous serial transmission RS485.

Which Divers can be used with the Diver-MOD?

The following Divers can be used with the Diver-MOD:

  • TD-Diver (DI8xx)
  • Micro-Diver (DI6xx)
  • Cera-Diver (DI7xx)
  • CTD-Diver (DI27x)
  • Baro-Diver (DI800, DI500)
  • Mini-Diver (DI5xx)

What types of cables do I need?

The Diver Data Cable AS2xxx must be used to connect the Diver to the Diver-MOD.
For connecting the Diver-MOD to the Modbus system RS485 cables with a diameter from 3.5 to 7 mm are preferred.

Will the Diver-MOD deliver compensated data?

The Diver-MOD contains a barometric sensor, but there are no datalogging capabilities for the barometric data. Real-time data that can be requested is Diver pressure, temperature, conductivity (if applicable), barometric pressure, and air temperature. Note that there is no compensated pressure. Compensation must be done by the supervisory computer.

What will happen if the Diver-MOD exceeds the operating temperature limits?

The Diver-MOD will not operate within specifications if the temperature exceeds the operational temperature range of -20 to 80 °C.

How fast can real-time Diver values be read using the Diver-MOD?

Updated real-time values from the Diver can be read every 0.5 second.

How long does it take to read the Diver memory?

This depends on factors such as:

  • How much of the Diver data is already copied to the memory of the Diver-MOD
  • The bitrate of the RS485 interface
  • The amount of data to be read

If the Diver data is already copied to Diver-MOD memory, a full memory can be read within one minute.

What is the current draw of the Diver-MOD?

What is the current draw of the Diver-MOD?

The standby power consumption is approximately 2 mA (no activity of Diver or RS485) and in active mode the average power consumption is approximately 10 mA.