DeltaV OPC Data Access Server functional overview > DCOM Setup

Set DCOM access and launch permissions

In order for the DeltaV OPC Data Access Server service to run, the DCOM access and launch permissions must be set on the server machine. Most permissions are set when DeltaV software is installed. However, you must manually set permissions for anonymous logon. To confirm DCOM permissions and to set permissions for anonymous logon, complete the following steps:

  1. Run the executable file, dcomcnfg.exe.
    The Component Services window opens.
  2. In the left pane, open Component Services.
    A Computers folder appears.
  3. Open the Computers folder.
    The My Computer icon appears.
  4. Right-click the My Computer icon, and then select Properties.
  5. Select the COM Security tab, and then click the Edit Limits button in the Access Permissions group.
  6. From the Group or user names list, select ANONYMOUS LOGON, and then enable the Allow option for both Local Access and Remote Access permissions.
    Important

    Neglecting to enable the Allow option for Remote Access permissions prevents an OPC client on a non-DeltaV workstation from being able to connect to the redundant DeltaV OPC Data Access Server on an Application Station pair set up for redundancy.

  7. Open the My Computer icon.
    Several folders appear.
  8. Open the DCOM Config folder.
  9. Right-click FrsOpcDv in the list that appears, and then select Properties.
  10. Select the Security tab.
    The Access permissions should include the accounts that need to connect to the DeltaV OPC Data Access Server. The SYSTEM account is the only account with Launch permission. The System account will also have Access permission. The accounts that need to connect are the ones that will actually be running the client application. If these are not Domain accounts then the user name and password must match on both the server and client machines for Windows to recognize the users as the same account. The user name must also be a DeltaV user on the server machine (defined by running DeltaV User Manager).
    Note

    After the server is running, the launch permission setting is not used. The only user that launches the server is SYSTEM. Any other client accessing the server bypasses launch permissions and requires Access permission only.

  11. Select the Identity tab.
    The This user option should have been selected and DeltaVAdmin should be the user name. This tells COM how to launch the server. There are three options:
    • Interactive User - Server is launched as user who is currently logged on the machine. If nobody is logged on, launch fails.
    • Launching User - Server is launched with account running the client application on the other machine.
    • This user/User - DCOM logs on the specific User in the background and starts server using caller's token. This is the setting needed for the DeltaV OPC Data Access Server.
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