In contrast to the NodeSet files the plugin gets not only notified when some changed, but also a reference to the UML Element which changed, therefore reducing the overhead as only a single Element has to be transformed.

A UML to OPC UA NodeSet transformation typically goes through the following steps

• Get NodeSet Element
• Synchronise Values
• Link References

In an internal data structure called matching, UML Elements get mapped to NodeSet Elements. If there is no mapping created for the UML Element, a new NodeSet Element will be added to this matching.

In the next step all attributes of the Stereotype will be read out and the corresponding attributes will be set inside the NodeSet Element.

If some other UML is referenced this referenced will be looked up in the mapping, if it does not exist it will be transformed. The transformed element will then be linked via the NodeId or added as child.