Arrays

By default arrays are regarded as individual nodes in the UA namespace. This means that if you define, for example, an array dyn_BOOL[10] in the PLC (and have also enabled it for OPC UA), it will subsequently appear in the UA namespace as follows:

The advantage of this approach is a considerable reduction in the complexity of the UA namespace and in memory consumption, since not every position of an array needs to be made available as an individual node in the namespace. However, modern UA Clients can continue to access the individual array positions via the so-called "RangeOffset".

In order to support older UA Clients that don’t offer this feature, however, you can also make the positions of an array available as individual nodes in the UA namespace. It is illustrated as follows:

This setting is available by activating the Legacy Array Handling option in the UA Configurator within the respective namespace configuration.

Depending on the scope of the PLC project, the UA namespace can become significantly more complex, which in turn is reflected in an increased memory utilization of the UA Server.

Changes to the settings listed above only become active after restarting the UA Server.