Table 38 describes the details of the Standard DataChange Subscription Server Facet. This Facet specifies the standard support of subscribing to data changes. This Facet extends features and limits defined by the Embedded Data Change Subscription Facet. As a minimum, Servers shall support 2 Subscriptions with at least 100 items for at least half of the required Sessions. The 100 items shall be supported for at least half of the required Subscriptions. Queuing with up to two queued entries is required. Support of five parallel Publish requests per Session is required. This Facet also requires the support of the triggering service. This Facet has been updated to include optional ConformanceUnits to allow for backward compatibility. These optional ConformanceUnits are highly recommended, in that in a future release they will be made mandatory.

Table 38 – Standard DataChange Subscription Server Facet

Group	Conformance Unit / Profile Title	Optional
Profile	Embedded DataChange Subscription Server Facet	False
Base Information	Base Info GetMonitoredItems Method	True
Method Services	Method Call	True
Monitored Item Services	Monitor Items 10	False
Monitored Item Services	Monitor Items 100	False
Monitored Item Services	Monitor MinQueueSize_02	False
Monitored Item Services	Monitor Triggering	False
Monitored Item Services	Monitored Items Deadband Filter	False
Subscription Services	Subscription Minimum 02	False
Subscription Services	Subscription Publish Min 05	False