4.5.4 DeviceHealth Interface

The DeviceHealth Interface includes Properties and Alarms that are commonly used to expose the health status of a Device. It is illustrated in Figure 7 and formally defined in Table 21.

Figure 7 – DeviceHealth Interface
Table 21 – IDeviceHealthType definition
Attribute Value
BrowseName1:IDeviceHealthType
IsAbstractTrue
References NodeClass BrowseName DataType TypeDefinition Other
Subtype of the 0:BaseInterfaceType defined in OPC 10000-5
0:HasComponentVariable1:DeviceHealth1:DeviceHealthEnumeration0:BaseDataVariableTypeO
0:HasComponentObject1:DeviceHealthAlarms0:FolderTypeO
Conformance Units
DI DeviceHealth

DeviceHealth indicates the status as defined by NAMUR Recommendation NE107. Clients can read or monitor this Variable to determine the device condition.

The DeviceHealthEnumeration DataType is an enumeration that defines the device condition. Its values are defined in Table 22. Its representation in the AddressSpace is defined in Table 23.

Table 22 – DeviceHealthEnumeration values
NameValueDescription
NORMAL0The Device functions normally.
FAILURE1Malfunction of the Device or any of its peripherals. Typically caused device-internal or is process related.
CHECK_FUNCTION2

Functional checks are currently performed. Examples:

Change of configuration, local operation, and substitute value entered.

OFF_SPEC3"Off-spec" means that the Device is operating outside its specified range (e.g. measuring or temperature range) or that internal diagnoses indicate deviations from measured or set values due to internal problems in the Device or process characteristics.
MAINTENANCE_REQUIRED4Although the output signal is valid, the wear reserve is nearly exhausted or a function will soon be restricted due to operational conditions e.g. build-up of deposits.
Table 23 – DeviceHealthEnumeration definition
Attribute Value
BrowseName1:DeviceHealthEnumeration
IsAbstractFalse
References NodeClass BrowseName DataType TypeDefinition Other
Subtype of the 0:Enumeration type defined in OPC 10000-5
0:HasPropertyVariable0:EnumStrings0:LocalizedText []0:PropertyType
Conformance Units
DI DeviceHealth

DeviceHealthAlarms shall be used for instances of the DeviceHealth Alarm Types specified in 4.12 and any other subtypes of DeviceHealthDiagnosticAlarmType.

It is recommended to use the DeviceHealthAlarms folder also for Alarm instances that relate to the health condition of the Device and are not subtypes of DeviceHealthDiagnosticAlarmType