Table 60 describes the details of the A & E Wrapper Facet. This Facet specifies the requirements for a UA Server that wraps an OPC Alarm & Event (AE) Server (COM). This Profile identifies the sub-set of the UA Alarm & Condition model which is provided by the COM OPC AE specification. It is intended to provide guidance to developers who are creating servers that front end existing applications. It is important to note that some OPC A&E COM Servers may not support all of the functionality provided by an OPC UA A&C server, in these cases similar functionality maybe available via some non-OPC interface. For example if an A&E COM server does not support sending Alarm Acknowledgement messages to the system that it is obtaining alarm information from, this functionality may be available via some out of scope features in the underlying Alarm system. Another possibility is that the underlying system does not require acknowledgements or automatically acknowledges the alarm.

Table 60 – A & E Wrapper Facet

Group	Conformance Unit / Profile Title	Optional
Address Space Model	Address Space Events	False
Address Space Model	Address Space Notifier Hierarchy	False
Address Space Model	Address Space Source Hierarchy	False
Alarms and Conditions	A & C Acknowledge	False
Alarms and Conditions	A & C Alarm	False
Alarms and Conditions	A & C Basic	False
Alarms and Conditions	A & C ConditionClasses	False
Alarms and Conditions	A & C Refresh	False
Alarms and Conditions	A & E Wrapper Mapping	False
Monitored Item Services	Monitor Basic	False
Monitored Item Services	Monitor Complex Event Filter	False
Monitored Item Services	Monitor Events	False
Monitored Item Services	Monitor Items 2	False
Monitored Item Services	Monitor QueueSize_ServerMax	False
Subscription Services	Subscription Basic	False
Subscription Services	Subscription Minimum 1	False
Subscription Services	Subscription Publish Discard Policy	False
Subscription Services	Subscription Publish Min 02	False