Run an OPC DA Server as a Service
- Last UpdatedSep 12, 2025
- 2 minute read
By default, Plant SCADA operates under the "NT SERVICE\Citect Runtime Manager" virtual service account when running as a service. This is not suitable for a system that includes an OPC DA server, as this type of server uses specific DCOM settings that are not compatible with the virtual service account.
To address this situation, you need to make the following configuration changes on the computer where an OPC DA server will run as a service:
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Specify a particular user account under which the Plant SCADA service will operate (see Run as a Service Under a Specific User Account).
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In the DCOM settings for the OPC DA server, confirm that the same user account is used as the identity that operates the server.
To specify the DCOM identity that operates the OPC DA server:
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Open the Component Services console (for more information, refer to the operating system documentation provided by Microsoft™).
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In the list of Component Services, open the My Computer branch, then the DCOM Config directory.
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Right-click on the SCADA OPC DA Server and select Properties.
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Go to the Identity tab, and select the This User option.
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Enter the name and password for the account that is configured to operate Plant SCADA as a service.
The OPC DA server will now operate as a service with appropriate DCOM credentials.
Note: If you need to return Plant SCADA to normal operation (that is, you will no longer run it as a service), you will need to set the DCOM identity for the OPC DA Server back to Interactive user.