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OPCDA client

Driver that can be used to connect to OPC-DA (Classic) servers. The functionality is similar to the newer OPCDA, but will work just in Windows because it makes use of COM objects.


Aside from the common parameters described in the communication_driver docs, this driver includes:

  • server: Name of the OPC DA server to connect to. Default = 'Matrikon.OPC.Simulation.1'
  • async_connection: This variable can be set to true to use async reading (subscription). Default = False

Setup data

The setup data will give values to the parameters required and will specify the I/O variables info.

    "parameters": {
        "server": "Matrikon.OPC.Simulation.1",
        "async_connection": true
    "variables": {
        "sensors": {
            "datatype": "byte", 
            "size": 1,
            "operation": "write"
        "actuators": {
            "datatype": "byte", 
            "size": 1, 
            "operation": "read"


The setup_params in the generic PLC components for opcda_client will need the following format:

{"server": "Matrikon.OPC.Simulation.1", "async_connection": true}