Error message: RPC server is not available (0x800706BA)

When an OPC Client reports this DCOM error (0x800706BA) then the OPC Client is unable to connect to an OPC Server or loses an existing connection. The OPC Client doesn’t detect the loss of connection. The OPC Client can’t access data from the OPC Server. The callbacks for data exchange don’t get through from the Server to the Client.

This might have different reasons:

  • The OPC Server is not responding to a DCOM call due to deadlock / crash
  • The OPC Server is not responding to a DCOM call due to a bad DCOM configuration.
  • The Firewall is on
  • The OPC Server is not available due to network interruption.

The problem often lies in the user context under which the Server is running (DCOM Identity Setting). Therefore please configure a user with administrator privileges and password and start the application under this user. In the most cases this DCOM setting is helpful.

The DCOM settings are however not part of our scope since the DCOM is a service of the Microsoft Windows operating system. For further information about it please visit the Microsoft Websites.