If the computers involved in sending and receiving data via the OPC DA protocol are not joined to an Active Directory domain, create user accounts with the same name and password for each of these computers.
To establish an OPC DA connection, configure access permissions for the Distributed Component Object Model (DCOM) protocol.
To configure access permission for the DCOM protocol:
Press the Win+R key combination.
The standard Microsoft Window Run window opens.
Enter dcomcnfg in the Open field and press OK.
The Component Services window opens.
In the left part of the window, in the folder tree, select Component Services → Computers → My Computer.
Right-click to bring up the context menu of the My Computer folder and select Properties.
The My Computer Properties window opens.
Select the COM Security tab in the My Computer Properties window.
In the Access Permission section, click the Edit Limits button.
The Security Limits tab opens in the Access Permission window.
In the Group or user names section, select the ANONYMOUS LOGON group.
In the Permissions for ANONYMOUS LOGON table, in the Allow column, select the Remote Access check box.
To save the changes, click OK.
Click the OK button in the Properties: My Computer window.