Install an OPC UA Server

An OPC UA server allows Plant SCADA's runtime system to function as a server to OPC UA client applications.

Note: In this release of Plant SCADA, the OPC UA server has the following functionality limitations:
• The server supports DA only.
• Quality tag extensions are represented as a numeric value. Only the OPC quality is exposed.
• Alarm Properties as Tags are not exposed.
• Extended quality modes "Control Inhibit" and "Tag Override" are not available.
• Redundant OPC UA servers are not supported.

Tag extensions are included in the OPC UA browse hierarchy. Of those presented, a client can subscribe to the following:

• Field

• Control Mode

• Override Mode

• Valid

• Status

• Override

Following installation, you can configure the OPC UA server via Configurator's OPC UA Server plugin under Plant SCADA. This has four configuration options:

• Port number – the port number the OPC UA server will listen on.

• URL – the URL to use to connect an OPC UA client to the OPC UA server (read only).

• Enable Encryption – This option allows encrypted communications between the OPC UA server and a connected client.

• Allow Anonymous access – Checking this option allows anonymous users to connect to the OPC UA server.

See Use Configurator to Set Up an OPC UA Server.

If the OPC UA server is installed on a separate computer, you will need to configure a deployment server and client to deploy the relevant project information to the OPC UA server. Once the project files have been deployed, the OPC UA server will start using the new configuration automatically.

To communicate with the Plant SCADA runtime system, you also need to connect the OPC UA server to a System Management Server to enable encrypted communication with the Plant SCADA servers.

Note: The OPC UA server requires the purchase of a specific license. Please contact your Plant SCADA distributor for more information.

Note: The OPC UA Server’s browse functionality will always retrieve a tag name with the cluster prefix. However, if you manually subscribe to a Plant SCADA tag using its tag name, the OPC UA Server may reject the subscription request if a cluster is not explicitly defined. This will occur if the compiler determines that your SCADA system tags are not globally unique across all clusters. If this occurs, you can use the parameter [General]EnforceTagGlobalUniqueness to diagnose which tags are not globally unique.

See Also

OPC UA Server Installation Requirements

OPC UA Server Installation Procedure

Use Configurator to Set Up an OPC UA Server

Confirm the Settings for an OPC UA Server