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Virtual Device OPC UA Server

The input and output values of a Revolution Pi system (I/O values) can be exchanged via the OPC UA protocol. The web application PiCtory can configure a virtual component as an OPC UA server. No programming is necessary.

Prerequisites​

✓ RevPi base module with RevPi Bullseye Image or higher

✓ PiCtory version 2.3.0 or higher

✓ Your RevPi base module is located in your network

Configure OPC UA Server​

▷ Start PiCtory.

▷ Select your RevPi base module from the Device Catalog and drag and drop it onto the empty slot with position number 0.

▷ Drag and drop the Virtual Device OPC UA Server from the Device Catalog onto the Configuration Board.

▷ Click on the Virtual Device OPC UA Server in the Configuration Board to highlight it.

     ❯ The Device Data and Value Editor areas appear under the Configuration Board.

▷ Under MEM Port, configure the port via which the OPC UA server should be accessible:

  • Default port: 4840
  • Port for TLS: 4843

▷ Select for MEM Shared_IOs either All existing or only Marked as exported I/O values.

▷ For MEM Output_mode, select whether the linked outputs are only read ((ead only) or whether write authorization is granted so that an OPC UA client can also set values for the outputs (Read and write).

TLS Encryption​

If TLS certification is activated, valid certificates must be stored for both the server and the client. You can use your own, self-signed certificates. Open source tools such as XCA (X Certificate and Key Management) offer templates for TLS_client and TLS_server certificates.

▷ Under MEM Use_TLS-encyption, configure whether TLS encryption is active or inactive for the server connection.

▷ Configure the internal path to the server certificate under MEM TLS- certificate_path.

▷ Configure the internal path to the private key used by the server under MEM TLS_key_path.

Structured Data via replace_io_file​

The pre-installed RevPiModIO2 library contains the I/O replacement for the virtual devices. This converts the pure BYTEs or WORDs of the virtual devices into suitable data types.

▷ Configure the path to the definition file for MEM Replace_IO_file.

▷ Delete the value from MEM Replace_IO_file, if no definition file is to be loaded.