OPC Server V3 - Can't Access with OPC Client

  • barnstormer

    barnstormer - 2017-11-07

    I configured the OPC Server v3 using the instructions. The OPC Server connects to the gateway and my two test variables/symbols are available, according to the OPC Server log file. The OPC server is running on the same computer as the Gateway.

    However, I can't connect to the Gateway computer using an OPC Client (UaExpert). (Different computer) UaExpert provides an error: Could not connect to Server. BadCommunicationError.

    I can ping the gateway computer and the firewall is turned OFF on the Gateway computer.

    Which port should I use in the OPC Client? Port 4840 is not open on the Gateway computer. Port 4840 is open on the PLC and I can connect the UaClient directly to the PLC and access the variables/symbols.

    How do I troubleshoot? The OPC Server has a nice log file, but I can't find the Gateway log file to search for clues.


  • eschwellinger

    eschwellinger - 2017-11-16

    I never tried to used OPCUA Expert to connect an "OPCDA Connection",
    is this really possible?
    I would try to use other OPCDA Clients, like Matrikon ... etc to connect to an OPCDA Server. (See the opcda faq's in the forum)
    Anyway you should think on adding the OPCUA Server to your CODESYS V3 plc runtime and use OPCUA Client to
    connect to the plc (yes in this case UA Expert) - this is more secure even OPCUA encryptet communication is possible since 3.5SP11 release ( all Linux SL products - 3.5SP12 release)
    This is meanwhile important too. (think on the security aspect)



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