The DeviceHealth Property defined in 5.5.4 provides a basic way to expose the health state of a device based on NAMUR NE 107.

This section defines AlarmTypes that can be used to indicate an abnormal device condition together with diagnostic information text as defined by NAMUR NE 107 as well as additional manufacturer specific information.

Figure 18 informally describes the AlarmTypes for DeviceHealth.

image021.png

Figure 18 – Device Health Alarm type hierarchy

The DeviceHealthDiagnosticAlarmType is a specialization of the InstrumentDiagnosticAlarmType intended to represent abnormal device conditions as defined by NAMUR NE 107. This type can be used in filters for monitored items. Only subtypes of this type will be used in actual implementations. The Alarm becomes active when the device condition is abnormal. It is formally defined in Table 31.

Table 31 – DeviceHealthDiagnosticAlarmType definition

Attribute

Value

BrowseName

DeviceHealthDiagnosticAlarmType

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the InstrumentDiagnosticAlarmType defined in OPC 10000-9.

HasSubtype

ObjectType

FailureAlarmType

Defined in clause 5.12.3

HasSubtype

ObjectType

CheckFunctionAlarmType

Defined in clause 5.12.4

HasSubtype

ObjectType

OffSpecAlarmType

Defined in clause 5.12.5

HasSubtype

ObjectType

MaintenanceRequiredAlarmType

Defined in clause 5.12.6

Conditions of subtypes of DeviceHealthDiagnosticAlarmType become active when the device enters the corresponding abnormal state.

The Message field in the Event notification shall be used for additional information associated with the health status (e.g. the possible cause of the abnormal state and suggested actions to return to normal).

A Device may be in more than one abnormal state at a time in which case multiple Conditions will be active.

The FailureAlarmType is formally defined in Table 32.

Table 32 – FailureAlarmType definition

Attribute

Value

BrowseName

FailureAlarmType

IsAbstract

True

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the DeviceHealthDiagnosticAlarmType defined in 5.12.2.

The CheckFunctionAlarmType is formally defined in Table 33.

Table 33 – CheckFunctionAlarmType definition

Attribute

Value

BrowseName

CheckFunctionAlarmType

IsAbstract

True

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the DeviceHealthDiagnosticAlarmType defined in 5.12.2.

The OffSpecAlarmType is formally defined in Table 34.

Table 34 – OffSpecAlarmType definition

Attribute

Value

BrowseName

OffSpecAlarmType

IsAbstract

True

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the DeviceHealthDiagnosticAlarmType defined in 5.12.2.

The MaintenanceRequiredAlarmType is formally defined in Table 35.

Table 35 – MaintenanceRequiredAlarmType definition

Attribute

Value

BrowseName

MaintenanceRequiredAlarmType

IsAbstract

True

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the DeviceHealthDiagnosticAlarmType defined in 5.12.2.