Connecting an OPC UA client to the NETx Server

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.

After having installed the OPC UA extension, some basic settings have to be done. To do so, start the studio and open the menu entry Modules > OPC UA > OPC UA server configuration...

First, enable the OPC UA driver by ticking Enable OPC UA. Find more information about the remaining configuration options in the reference manual.

After having changed the required settings, the server needs to be restarted.

Now the Server Items of the NETx Server are available through OPC UA. To connect from an OPC UA client, an OPC UA connection URL for the NETx Server is required. Find the configured server URLs in the System Log Messages after server startup. Open the system log file and search for the following entries:

Plugin.OPCUA The following Endpoint URLs are available:
Plugin.OPCUA opc.tcp://<host name>:48400/UA/NETxBMSPlatform Security: http://opcfoundation.org/UA/SecurityPolicy#None
Plugin.OPCUA opc.tcp://<host name>:48400/UA/NETxBMSPlatform Security: http://opcfoundation.org/UA/SecurityPolicy#Basic256Sha256
Plugin.OPCUA opc.tcp://<host name>:48400/UA/NETxBMSPlatform Security: http://opcfoundation.org/UA/SecurityPolicy#Basic256Sha256
Plugin.OPCUA https://<host name>:48401/UA/NETxBMSPlatform/ Security: http://opcfoundation.org/UA/SecurityPolicy#Basic256Sha256
Plugin.OPCUA OPC UA started

Using these URLs, any OPC UA client can connect to our NETx Server.

Access rights and permissions

If an OPC UA client is connecting to an OPC UA server, a secure transport channel is established. In addition, the OPC UA client must authenticate to the OPC UA server using a username and password. In the OPC UA server configuration it is possible to define one user (i.e. username and password) who has full access to the whole OPC UA address space:

As an alternative, anonymous authentication (i.e. connection without username / password) can be enabled:

For our NETx BMS Platform, a more sophisticated authentication scheme is possible. If enabled, the user database of the NETx BMS Platform can be used:

This means that the same username and password combinations are used as for the visualization and Web Manager login. Starting with NETx BMS Platform R2 Build 1000, for each BMS user, the role permission for OPC UA can be configured within the Web Manager:

Role	Permission
Super Administrator	full access to the OPC UA address space
Administrator	full access to the OPC UA address space
Manager	full access to the OPC UA address space
Viewer	read-only access to the OPC UA address space

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