Unified Automation Forum

Hello,
I'm using UaExpert 1.5.1 with an OPC UA server I wrote. To keep the client updated in terms of model changes, I introduced a specialization of GeneralModelChangeEventType called DeviceListChangeEventType. This special type does not have any additional information, it's just there because GeneralModelChangeEventType is abstract (according to the OPC UA specification) and cannot be used directly.

Now, if UaExpert receives an event of type "DeviceListChangeEventType", a message "Unexpected EventType in ModelChangeEvent" is displayed and the event is obviously not handled like a GeneralModelChangeEventType event. In the server address space visualization, the new event type is correctly displayed as subtype of GeneralModelChangeEventType.

Just out of curiosity, I overwrote the EventType variable of the DeviceListChangeEventType events with the GeneralModelChangeEventType's NodeId. After that, UaExpert handles those events without complaining, correctly rebrowsing the affected nodes and updating the GUI. But I'm pretty sure, that's not the way it's supposed to be.

So is this a bug in UaExpert or is my interpretation of the whole ModelChange thing wrong?

Thanks for your replies,
Best regards
Michael

Update: it turned out that this was a bug on the server side, which prohibited the creation of abstract event types. But instantiating abstract event types is clearly allowed, as long as those events do not appear in the server address space.