3. Limit OPC Server Instances

Microsoft DCOM configuration security determines what instance of the OPC Server a client can attach to.

As a default, each time an OPC client launches the OPC server, the server is launched using the privileges and permissions of the user currently logged on.

If clients have different privilege levels DCOM will open separate instances of the OPC Server to accommodate the different privileges.

Beginning with CIMPLICITY 7.0 there is no inherent problem with running more than one instance of the OPC Server.

However, each instance does take up memory and resources.

If you need to conserve your Windows XP or Windows 2003 system memory and resources you can configure DCOMCNFG identity settings to run as an Interactive User.

Step 3.1

Open the CIMPLICITY HMI OPC Server Properties dialog box.

Step 3.2

Set DCOMCNFG settings for the CIMPLICITY OPC Server.

Step 3.3

Select DCOM access for the selected user.

More information

Troubleshoot OPC connections.