The Unitronics company (http://www.unitronics.com, Israel) supplies (free of charge) the OPC server for communication with their devices. This software is a part of the installation CD-ROM that is supplied with each unit by default.
The usage of the PmaOpcDaClient object requires purchase of the "PmOPC" licence. With the freeware version PmFree, or when developing the application (with development environment for tersting purposes), this component is always functional.
For this communication in the PROMOTIC system can be used: PmModbusMr - Driver for communication by the Modbus Master protocol.