OPC Server Setup

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Use of the OPC Server Setup tag is restricted to VTScada installations that include this feature as part of the license key. You can confirm whether this feature is enabled by opening the About VTScada dialog from the VTScada Application Manager.

Reference Notes:

Server Name: Trihedral.VTSOPC.DA

The VTScada OPC Server supports the OPC DA (Data Access) Standard.

The OPC Server Setup tag is used to turn your application into an OPC Server. Minimal VTScada configuration is required on your part to do this.

OPC security is handled by Windows via user and group security permissions set using the Microsoft Component Services dialog and the COM Security tag of the My Computer dialog. Please refer to Securing an OPC Server for more information on OPC security.

Only one OPC server may be defined per application. Attempting to define a second server in the same application will result in an error dialog stating "An application can have at most one OPC Server Setup tag".

Note: Use of the same name space for more than one application is strongly discouraged as it will cause significant problems.

There are no widgets for this tag. When the OPC Server Setup tag has been created, the application’s OPC-supporting tags become available on the VTScada OPC server.

OPC Server Setup properties Settings tab

An OPC Server has two configurable properties in addition to its ID information:

  • The name space for this application on the Trihedral OPC Server. This is a required field.
  • The Disallow Writes check box is there as a security feature. If selected, clients can query data from the server, but cannot write to it.

As a convenience, the server’s Prog ID will also be shown in this screen.

You may find it easiest to reuse the application's name for the server namespace. You should not use the same name space for two applications.