Error is related to access permissions. Could you please check DCOM Security and Configuration . Request you to check evertvwr for security and system errors when you are trying to connect from client. Eventvwr, system logs shows error specific to user id if there is any issue with Dcom user id you are using. Request you to check OPC logs as well if it has some problem after connecting.
As mentioned by Lal Babu, error 0x80070005 is a DCOM error. Check if the OPC Server application is actually running on the OPC Server PC. If you received this error when you tried to browse for OPC Servers on the OPC Server PC, check if OpcEnum is running. If either is running, end both processes on the OPC Server PC. Then try to establish communication again. If you still receive the same DCOM Error 0x80070005, then the cause is as listed below,
- On the OPC Server PC, the OPC Client User Account does not have the right Access Control List (ACL) permissions in the System-Wide DCOM settings, Access Permissions, Edit Default.
- On the OPC Client PC, the OPC Server User Account does not have the right Access Control List (ACL) permissions in the System-Wide DCOM settings, Access Permissions, Edit Limits.
- On the OPC Client PC, the DCOM Default Impersonation Level is set to "Anonymous" instead of "Identify", and the "ANONYMOUS LOGON" Access Control Entry (ACE) does not exist in the OPC Client PC, Access Control List (ACL) permissions in the System-Wide DCOM settings, Access Permissions, Edit Limits.
In addition to the helpful replies you already received, take a look at the account running the OPC Interface and the account running the OPC Server. Note that the account under which the OPC Server runs needs to connect back to the interface node. If you are using a local account, you may need to create an identical local account on the interface node.