You can configure important system parameters such as network settings, etc. using Telnet. It is opened on port 1111.
Telnet 192.168.180.20 1111
Among other things, you can change the network parameters, start/exit services and shut down the system.
Adding DCOM users
Use Option  DCOM Users menu:
Now, select Option  Add new DCOM user and enter the user name. Make sure that this is the same user name as used for the OPC client. Please note that the client user could also be a Windows service account.
Then, enter the password for this DCOM user. It has to be identical to the password in the client system.
As the last step, check the new DCOM user's account by listing all available users with Option  List/Edit DCOM user: