Add an OPC UA server as a tag integration source

This task describes how to add an OPC server as a tag integration source in your project. It is based on our built-in OPC UA client, which can communicate with OPC servers over Ethernet using the OPC Unified Architecture (OPC UA) specification.

Before you begin this task, you should be familiar with the OPC UA specification. For more information, go to: opcfoundation.org/about/opc-technologies/opc-ua/

You should also review the documentation for your specific OPC server software. Make sure the server is running and accessible on your network, and then note its network address.

Note: Tag integration for OPC UA does not support security or authentication. You can use an OPC UA server as a tag integration source only if the OPC UA connection has no security settings (set in the connection Security Settings dialog) and no login credentials (no User Name or Password, which requires the OPC UA server to be configured to accept anonymous connections).

Note: This task applies to OPC UA servers only. If you have an OPC DA server, see Add an OPC DA server as a tag integration source.

To add an OPC UA server as a tag integration source in your project:

1. On the Project tab of the ribbon, in the Settings group, click Communication.

   The Project Settings dialog is displayed, with the Communication tab selected.

   

2. In the Tag Integration area, click Add.

   The Tag Integration Source dialog box is displayed.

3. In the Type box, select Integrated if it is not already selected.

4. In the Provider box, select OPC UA.

5. In the Name box, type an appropriate name for the tag integration source.

   This name will be added as a prefix to the names of the integrated tags. The default is DEV, which is short for "device".

6. Click Add.

   The OPC UA Tag Integration dialog box is displayed.

   

7. In the Server box, select the connection to the OPC server.

   OPC UA tag integration is based on our built-in OPC UA client, so you are selecting from the connections created for that client. You can select a connection that you previously created, or you can click the "add" button (+) to the right of the Server box in order to create a new connection. For more information, see Create a new OPC UA connection.

8. In the Publish rate box, type the frequency (in milliseconds) at which the OPC server should publish updates to the client (i.e., your project).

   The publish rate is actually set when the client establishes its connection to the server.

9. In the Group size box, type the maximum number of items that may be read or written in a single operation.

   The default group size is 0, which means there is no limit and changes in item values will be immediately read and written (according to the publish rate). This is acceptable in most cases, but if you use a large number of items in your project and the values of those items change frequently, then read/write operations might overload the project and decrease runtime performance. You can specify a group size (for example, 64) in order to moderate those read/write operations and restore runtime performance.

10. In the Root node or view box, specify the server node that will serve as the root for all items. You can click the "more" button (…) to the right of the box in order to browse the server and then select a node.

    This step is optional, but specifying a root node makes it easier to find items and increases runtime performance.

11. Click OK to finish the configuration and add the source.

If the OPC server is successfully added as a tag integration source, its items will be immediately available for selection in the Object Finder. For more information, see Use the Object Finder to select integrated tags.