Implement OPC UA events feature (with limitations)
The OPC UA events feature is implemented on Server side with the following scope:
- Create event instances from available event types of address space
- Trigger event instances on an EventNotifier node
- Subscription create/modify MonitoredItem for events: where clause shall be empty or contain an OfType element (other elements not supported)
The client side provides the following scope:
- Simplified wrapper API to create/modify Event MonitoredItem
- API to receive event notification
Specific limitations:
- Event instance representation does not manage event as data node in address space (it might be managed manually by application)
- As a consequence, NodeId attribute value cannot be retrieved from an Event using Event MonitoredItem
- It is not possible to trigger an event on a Source node but only on the Notifier node
- Events are not propagated from source nodes to notifier nodes
- The only supported WhereClause element is a single OfType operation with a NodeId AttributeOperand
- SelectClause IndexRange validity is not checked based on EventType DataType/ValueRank on Create/ModifyMI
Edited by Vincent Monfort