0901-01 Subsystems

Example Projects > 0901 OPC UA > 0901-01 Subsystems

OPC UA server - Subsystems example

REXYGEN OPC UA server is a standalone application that acts as an OPC UA gateway. This application has to be configured and started independently. Start the OPC UA server service directly or using REXYGEN Tray Monitor.

This project example consists of a task, subsystems and blocks. It is sufficient to demonstrate possibilities of the OPC UA server.


  • REXYGEN Runtime Core must be installed and running on the target device to run the example.
  • REXYGEN OPC UA server must be installed and running on the target device.

Timing of the project

The algorithm runs each 100 milliseconds (0.1 s). See the EXEC function block,
tick x ntick0 = 0.05 x 2 = 0.1 s

MonitoredItems of the OPC UA server are synchronized once in the synchronizing interval. The synchronizing interval is set in the RexOpcUa.ini in the SYNC_INTERVAL variable. The default synchronizing interval is 500 milliseconds.

Running the examples

  • The *exec.mdl file is the project main file. Open it with REXYGEN Studio.
  • Study the individual subsystems, the first one is without a mask, the other one has it. The items in context menu will help here.
  • Compile and download the project to the target device.
  • Switch to Watch mode and keep it for later experiments.
  • Configure and start the OPC UA server service.
  • Configure and start your favourite OPC UA client.
  • Study the structure of blocks in the OPC UA Address Space. Try to read, monitor and write value of blocks' variables.


Additional information

  • Visit the REXYGEN webpage for more information about the example projects and developing advanced automation and control solutions using REXYGEN.