7 OPC UA Types and Instances 
7.11 WwEventsDispatcherType ObjectType Definition
The WwEventsDispatcherType represents a container that is an event dispatcher for machine events and is formally defined in Table 27.
Table 27 – WwEventsDispatcherType Definiton
| Attribute | Value | ||||
|---|---|---|---|---|---|
| BrowseName | WwEventsDispatcherType | ||||
| IsAbstract | False | ||||
| References | Node Class | BrowseName | DataType | TypeDefinition | Other |
| Subtype of the BaseObjectType defined in OPC 10000-5 | |||||
| 0:GeneratesEvent | ObjectType | 0:BaseEventType | |||
| 0:GeneratesEvent | ObjectType | WwBaseEventType |
A wide variety of events and states can trigger messages on a plant, machine or component. Events and the associated messages are rather temporary and therefore cannot be subscribed directly.
Figure 10 – Overview of Event Types
Woodworking machines do not need to provide the woodworking Types like WwBaseEventType. Instead it can be an object of any OPC UA 0:BaseEventType or a subtype of it and additionally can implement the interface IWwEventMessageType. So it is possible to use the full range of OPC UA AlarmTypes like 0:LimitAlarmType:
Figure 11 – OPC UA AlarmTypes