HasCondition is used to reference Conditions. The Reference is from a ConditionSource to a Condition instance or – if no instance is exposed by the Server – to the ConditionType.
Clients can locate Conditions by first browsing for ConditionSources following HasEventSource References (including sub-types like the HasNotifier Reference) and then browsing for HasCondition References from all target Nodes of the discovered References.
Figure 25 shows the application of the HasCondition Reference in a HasNotifier hierarchy. The Variable LevelMeasurement and the Object “Device B” Reference Condition instances. The Object “Tank A” References a ConditionType (MySystemAlarmType) indicating that a Condition exists but is not exposed in the AddressSpace.
Figure 25 – Use of HasCondition in a HasNotifier hierarchy