Base (no service packs) Windows
XP/2003 DCOM Configuration
NOTE: These directions will open up DCOM to all users.
NOTE: These steps are used to make sure that communication can be established. After
these steps have been followed to establish communication, DCOM permissions can be
tightened to allow only the necessary users.NOTE: These directions will open up DCOM to all users.
1) From the start menu go to run and type in dcomcnfg.
2) Component Services Dialog.
3) Under “Component Services” -> “Computers” ->Right Click on “My Computer.
4) Now go to the Default COM Security Tab.
5) Make sure that both the Access and Launch Permissions have “Everyone”, “Interactive”,
“Network” and “System” set to Allow.
6) Back on the My Computer Properties Dialog. Click on the Default Properties Tab.
Ensure that the settings on your machine match those in the screenshot below.
7) Click OK. You should now be looking at the Component Services Panel.
8) Underneath My Computer in the component services panel, there is a DCOM Config
Folder. Inside this folder are all of the DCOM Applications installed on the local
machine. We need to ensure that all of our OPC Servers are using the appropriate
NOTE: Due to a limitation in the Windows XP DCOM Configuration tool, not all OPC Servers
may be listed as their Application name, but instead as their Class ID number. If your OPC
Server is being listed by its Class ID please contact our support line for additional help.
9) Find your OPC Server(s) in the list. Right-Click on the OPC Server and select Properties.
10) Please ensure that your Authentication Level is set to ‘Connect’.
11) If you have successfully set up the Defaults for your system, you can decide if you want
this server to utilize the default settings, or custom settings.
12) If you choose default please skip the following steps for Launching and Access
13) Now that customize has been selected, please edit the default launch and access
permissions to contain the following users, “Everyone”, “Network”, “Interactive”,
14) Make sure that all of these users are set to Allow.
15) Under the Identity Tab, please ensure that your OPC Server is running as The
16) If your Server is running as a service you will not be able to select The Interactive
User, it will be under The System Account.
17) Please repeat steps 8 -> 16 for all OPC Servers installed on the machine.
18) Please note that these steps may need to be done on remote machines as well, please
repeat all steps as necessary.
Your DCOM is now setup to accept all incoming connections.
NOTE: DCOM has limitations for connectivity when operating on
separate domains/workgroups. These steps may work but,depending on
individual networks, additional settings and components may be
required. Please contact OPC Support for additional information.