Errors

CoCreateInstanceEX is a DCOM call that is made when you are connecting an OPC Client to a remote OPC Server. This error indicates that the call failed, and it is necessary to review your DCOM permissions for the defaults on both machines, the OPC Client (if applicable) and the OPC Server. To change these, you will have to access the DCOMCNFG tool and allow this communication. This holds true for both a user account, and the system account.  You can configure your COM and DCOM through use of the following documents (in pdf format):

DCOM on Windows NT/2000
DCOM on Windows XP/XP SP1/2003
DCOM on Windows XP SP2/2003 SP1

 

If you are experiencing DCOM issues across domains or while using workgroups, we strongly recommend downloading and installing MatrikonOPC Tunneller. MatrikonOPC Tunneller eliminates DCOM setup headaches and gets data flowing seamlessly between your servers and clients using TCP/IP.  Tunneller can also be used to ensure secure communication across firewalls.