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.

image010.png

Figure 7 – DeviceHealth Interface

Table 21 – IDeviceHealthType definition

Attribute

Value

BrowseName

IDeviceHealthType

IsAbstract

True

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the BaseInterfaceType defined in OPC 10001-7

HasComponent

Variable

DeviceHealth

DeviceHealthEnumeration

BaseDataVariableType

Optional

HasComponent

Object

DeviceHealthAlarms

FolderType

Optional

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.

Table 22 – DeviceHealthEnumeration values

Name

Value

Description

NORMAL

0

The Device functions normally.

FAILURE

1

Malfunction of the Device or any of its peripherals. Typically caused device-internal or is process related.

CHECK_FUNCTION

2

Functional checks are currently performed. Examples:

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

OFF_SPEC

3

"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_REQUIRED

4

Although 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.

DeviceHealthAlarms shall be used for instances of the DeviceHealth Alarm Types specified in 4.12.

DeviceHealthAlarms may also be used for other Alarm instances that relate to the health condition of the Device.