Table 46describes the details of the Standard Event Subscription ServerFacet. This Facet specifies the standard support for subscribing to events and is intended to supplement any of the FullFeatured Profiles. Support of this Facet requires the implementation of EventTypes representing the Events that the Servercan report and their specific fields. It also requires at least the Server Objectto have the EventNotifier Attributeset. It includes the Servicesto Create, Modify and Delete Subscriptions and to Add, Modify and Remove Monitored Items for Object Nodeswith an “EventNotifier Attribute”. Creating a monitoring item may include a filter that includes SimpleAttribute FilterOperands and a select list of Operators. The operators include: Equals, IsNull, GreaterThan, LessThan, GreaterThanOrEqual, LessThanOrEqual, Like, Not, Between, InList, And, Or, Cast, BitwiseAnd, BitwiseOr and TypeOf. Support of more complex filters is optional. This Facet has been updated to include several optional Base Information ConformanceUnits. These ConformanceUnitsare optional to allow for backward compatibility, in the future these optional ConformanceUnitswill become required, and so it is highly recommended that all servers support them.

Table 46– Standard Event Subscription Server Facet

Group	Conformance Unit / ProfileTitle	Optional
Address Space Model	Address Space Events	False
Base Information	Base Info Device Failure	True
Base Information	Base Info EventQueueOverflow EventType	True
Base Information	Base Info Progress Events	True
Base Information	Base Info SemanticChange	True
Base Information	Base Info System Status	True
Base Information	Base Info System Status Underlying System	True
Monitored Item Services	Monitor Basic	False
Monitored Item Services	Monitor Complex EventFilter	True
Monitored Item Services	Monitor Events	False
Monitored Item Services	Monitor Items 10	False
Monitored Item Services	Monitor QueueSize_ServerMax	False
Subscription Services	SubscriptionBasic	False
Subscription Services	SubscriptionMinimum 02	False
Subscription Services	SubscriptionPublish Discard Policy	False
Subscription Services	SubscriptionPublish Min 05	False