IEC 62541-3-2020 pdf free download

IEC 62541-3-2020 pdf free download.OPC unified architecture — Part 3: Address Space Model
Architecture unifiée OPC — Partie 3: Modèle d’espace d’adressage.
The Event Model defines a general purpose eventing system that can be used in many diverse vertical markets.
Events represent specific transient occurrences. System configuration changes and system errors are examples of Events. Event Notifications report the occurrence of an Event. Events defined in this document are not directly visible in the OPC UA AddressSpace. Objects and Views can be used to subscribe to Events. The EventNotifier Attribute of those Nodes identifies if the Node allows subscribing to Events. Clients subscribe to such Nodes to receive Notifications of Event occurrences.
Event Subscriptions use the Subscription/Monitoredltem Services defined in IEC 6254 1-4 to subscribe to the Event Notifications of a Node.
Any OPC UA Server that supports eventing shall expose at least one Node as EventNotifier.
The Server Object defined in IEC 62541-5 is used for this purpose. Events generated by the
Server are available via this Server Object. A Server is not expected to produce Events if the
connection to the event source is down for some reason (i.e. the system is offline).
Events may also be exposed through other Nodes anywhere in the AddressSpace. These Nodes (identified via the Even tNotifier Attribute) provide some subset of the Events generated by the Server. The position in the AddressSpace dictates what this subset will be. For example, a process area Object representing a functional area of the process would provide Events originating from that area of the process only. It should be noted that this is only an example and it is fully up to the Server to determine what Events should be provided by which Node.
4.6.2 EventTypes
Each Event is of a specific Event Type. A Server may support many types. This document defines the BaseEventType that all other EventTypes derive from. It is expected that other companion specifications will define additional EventTypes deriving from the base types defined in this document.IEC 62541-3-2020 pdf free download.