IEC 62056-21 Communication Driver

IEC 62056-21 Communication Driver is intended for data connection between Reliance's runtime software and telemetry systems communicating via the communication protocol according to the IEC 62056-21 standard.

Starting up the driver

The communication driver is a DLL loaded into memory by the Reliance 4 Driver Server program, which can be launched either as a Windows service at Windows startup or as a standard application at the start of a visualization project. Information required to make a connection with devices is read from the visualization project. After reading this information, communication to all connected devices is activated.

Supported Reliance versions

The communication driver is supported in both Reliance 5 and Reliance 4.

Reading data

Data is read periodically or based on a one-shot request of Reliance's runtime software. When reading periodically, the tag value is updated at a configured interval.

The communication driver allows for both reading the device's data via the so-called Data readout mode and reading tag values one by one in the so-called Programming mode. The way the data is read depends on the selection in a visualization project.

In addition to mode A with a constant rate of 300 Bd, the driver supports modes B and C with their initial rate changed to the rate supported by the telemetry system. Tag values can be provided in both text and digital formats.