Because Conditionsalways have a state (Enabledor Disabled) and possibly many sub-states it makes sense to have instances of Conditionspresent in the AddressSpace. If the Serverexposes Conditioninstances they usually will appear in the AddressSpaceas components of the Objectsthat “own” them. For example, a temperature transmitter that has a built-in high temperature Alarm would appear in the AddressSpaceas an instance of some temperature transmitter Objectwith a HasComponent Referenceto an instance of a LimitAlarmType.

The availability of instances allows Data Access Clientsto monitor the current Conditionstate by subscribing to the Attributevalues of Variable Nodes. The values of the nodes may not always correspond with the value that appear in Events, they may be more recent than what was in the Event.

While exposing Conditioninstances in the AddressSpaceis not always possible, doing so allows for direct interaction (read, write and Methodinvocation) with a specific Conditioninstance. For example, if a Conditioninstance is not exposed, there is no way to invoke the Enableor Disable Method for the specific Conditioninstance.