Access to Object Settings

Most server objects such as tags, devices, time series, etc. are represented as items of the OPC UA hierarchy.

The server offers the possibility to read and write most of the control and diagnostic properties of objects defined on the server. For example, through the OPC UA client you can change the host for a Modbus TCP device, set the update rate for a tag, etc. By default, access to the properties of the server objects is set to read-only mode. For tags, tag groups, time series and time series groups, properties are also not available for browsing through the OPC UA client.

Browsing properties of tags, tag groups, time series, and time series groups is not available by default in order to prevent creation of a large number of variables when importing OPC UA hierarchies into third-party systems such as SCADA

Access rights for specific categories of objects are configured in the security manager. After the credentials provided by the OPC UA client are associated with the role, the client will have access to the specified set of rights. By default, if the OPC UA client connects in anonymous mode, the server cannot authorize the client with the necessary set of rights, and therefore it provides access to all categories of objects.

To enable properties writing for server objects, open the OPC UA manager in Monokot Server Administrator, go to the Object Access tab and select Read/Write in the Access Mode to Object Properties drop-down menu.

Click Sync for the changes to take effect on the server. Other options available on the Object Access tab include:

• Allow access to object properties when connecting to the server in anonymous mode (enabled by default)

• Browse tag properties for OPC UA client

• Browse tag group properties for OPC UA client

• Browse time series properties for OPC UA client

• Browse time series group properties for OPC UA client

• Browse expression properties for OPC UA client

• Browse expression group properties for OPC UA client