Integrate data points from an OPC UA Server
- Nahel Falhout (Unlicensed)
- Wolfgang Granzer
- Reinhard Mayr (Unlicensed)
The NETx Servers provide a standardized OPC UA (Unified Architecture) interface. OPC UA is one of the most important communication protocols for Industry and the IoT.
Add remote server
The NETx Server provides an OPC UA client module to integrate data points from remote OPC UA servers. After having installed the plugin, open the menu entry Modules > OPC UA > Server definitions. Within this definition file, remote OPC UA servers can be added. In the following example another NETx Server Platform that is running as an OPC server is defined.
| Parameter | Description |
|---|---|
| Name | The given name of the OPC UA server in the NETx Server. The combination of name and path must be unique within this definition file. |
| Path | The generated path in the Item Tree. The combination of name and path must be unique within this definition file. |
| URL | The URL of the OPC UA Server. |
| Use Security | If set to true, a secure connection will be used to connect to the OPC UA server. |
| Add Unknown Certificates | If enabled, unknown certificates are accepted by the OPC UA client implementation. If disabled, the certificate must be trusted by this computer. A trusted certificate must be either an official certificate or the CA certificated must be located in the certificate store of the local computer (path "Local Computer\NETx BMS Platform"). |
| Username | If the OPC UA Server requires authentication with a username and a password. |
| Password | If the OPC UA Server requires authentication with a username and a password. |
| Write timestamps | Choose which timestamps shall be used for writing to OPC UA data points. |
Add remote data points (nodes)
Now the OPC UA data points can be defined. This is done in the menu item Modules > OPC UA > Data point definitions. In the following example, a data point from another NETx Server that is running as an OPC server is defined.
| Parameter | Description |
|---|---|
| Server Name | The full name of the remote OPC UA server. This must match the combination name and path from the server definitions. |
| Name | The name of the data point. The combination of name and path must be unique within this definition file. |
| Path | The generated path in Item Tree. The combination of name and path must be unique within this definition file. |
| Namespace Index | The index of the namespace URI in the namespace array. |
| NodeId Type | The type of the Node ID (by default String). |
| NodeId Value | The node ID of the data point. |
| Data type | The data type of the data point. |
| Access mode | read, read and write or write. |
| Persistent | This parameter specifies whether the value of the data point is persistent (restored from the database after server start up ) or not. |
Synchronize | If set to True (T), the value is synchronized between the main and backup server (if present). |
To determine the required namespace index, node id type, node id value and data type, you can use any 3rd party OPC UA client like UaExpert.
The added data points should appear in the Item Tree under the specified path: 
Fine tuning
To get data from OPC UA servers, the client has many different configuration options. These options are used to establish the connection as well as for the data retrieval (OPC UA subscription service). The options can be changed within the OPC UA Client Configuration.
For troubleshooting, the log level of the OPC UA driver can be increased. The corresponding log entries are stored in a separate log file (<WorkspaceDirectory>\LogFiles\xio.OpcUa.log). More information about the configuration can be found in the OPC UA driver configuration.
Article applies to the following products
- NETx BMS Platform
- NETx Multi Protocol Server
- NETx BMS Server 2.0