The OPC UA server provides an OPC/UA-compliant interface to all IAP-accessible datapoints on SmartServer IoT-to-OPC UA client applications (e.g., OPC UA compliant SCADA workstations AVEVA Edge HMI and GE Cimplicity HMI/SCADA). 

This section consists of the following:

Overview

OPC UA is a machine-to-machine communication protocol developed by the OPC Foundation. The SmartServer IoT OPC UA server supports up to 10,000 subscriptions and on-demand read (poll).

For Structure or Union Extension Object (such as SNVT_switch), the SmartServer IoT OPC UA server includes an as_string property type that will display the structure as a string data type at an OPC UA client. The feature is useful when an OPC UA client does not support Extension Object.

Other SmartServer features are as follows:

• SmartServer 2.8 and higher includes a preset feature that allows preset values to be used and displayed at the OPC UA client. It supports both anonymous and Basic256Sha256 (apollo user login) authentication settings.
  
• SmartServer 3.0 and higher supports input datapoint node priority read/write. 

Setting the OPC UA Configuration

The OPC UA Configuration page is used to enable the OPC UA server function. This page allows you to name the OPC UA server and port. The IP Address/Hostname should be 127.0.0.1. 

Click the Enable OPC UA Server option to provide support for this feature (disabled by default).

The OPC UA endpoint URL that is used by the OPC UA client to communicate with the OPC UA server is:

opc.tcp://<SmartServer IoT hostname>:55000/UA/echopcua-server

Examples:

opc.tcp://192.168.1.15:55000/UA/echopcua-server
opc.tcp://smartserver-17q4aa8:55000/UA/echopcua-server

For more information about supplying the <SmartServer IoT hostname> variable depending on your SmartServer environment, refer to the Connectivity Testing section found in Connect to Your SmartServer.

Save your changes to OPC UA configuration settings by clicking the Update button.

Disabling the Anonymous Connection End Point

You can disable the anonymous connection end point by modifying the OPCUA_config.xml file. With this setting change, the OPC UA Server will only publish the secure endpoint with username/password authentication. 

To disable the anonymous connection end point, perform the following steps:

1. Stop the OPC UA Server by disabling the Enable OPC UA Server option on the 1481131.
   
   
2. Click Update on the OPC UA Configuration page for changes to take effect.
   
   
3. Connect to the SmartServer at the console.
   
   
4. Enter the following command: cd /var/apollo/data/opcua
   
   

5. Modify the OPCUA_config.xml file by setting the <EnableAnonymousEndpoint>true</EnableAnonymousEndpoint> flag to false as indicated below.
   

   

6. Restart the OPC UA Server by enabling the Enable OPC UA Server option as described in the Setting the OPC UA Configuration section above and click Update to save your configuration changes.