OPC and DCOM Configuration. Typical problems with OPC on Windows 8, Windows Server 2012
5. Typical problems
5.1 RPC server unavailable
This error means that it is impossible to establish a network connection to the RPC service.
- If the error occurs during an attempt to get the list of OPC servers on the remote computer, you should check the firewall settings. The OpcEnum.exe file located in the Windows\System32 folder by default must be added to exceptions.
- You should make sure that inbound DCOM connections to port 135 are permitted
- If the error occurs during an attempt to connect to the OPC server, you should make sure that the executable file of the OPC server is added to the Windows firewall exception list.
5.2 Access denied
This error means that the current permissions are not enough to establish a connection. You should configure DCOM as described in section 4.
5.3 IOPCServerList interface not found
You should restart the computer after you install the OPC Core Components.
5.4 The OPC client can connect to a remote OPC server but does not receive information from the server
In the OPC Logger this error is showed as "Advise: Access denied". This error means that the server can't send data to the client computer. Please, start dcomcnfg.exe on the client computer, go to "Component Services - Computers - My Computer", right click over this node and configure the DCOM settings as showed below:
Fig. 1 DCOM settings
Restart the OPC client (OPC Logger, OPC Scada Viewer)
OPC and DCOM Configuration on Windows Server 2012 and Windows 8