This OPC UA ObjectType defines the super type for all OPC UA ObjectTypes that represent BACnet Analog object types in an OPC UA Address Space.

Figure 13 shows an overview for the BACnetAnalogType with its Properties and related ObjectTypes. It is formally defined in Table 12.

image019.png

Figure 13 BACnetAnalogType overview

The BACnetAnalogType is formally defined in Table 12.

Table 12 BACnetAnalogType Definition

Attribute

Value

BrowseName

BACnetAnalogType

IsAbstract

True

References

NodeClass

BrowseName

DataType

TypeDefinition

Other

Subtype of the BACnetObjectType defined in 7.1

0:HasComponent

Variable

Present_Value

0:Float

0:AnalogUnitType

M

0:HasProperty

Variable

Out_Of_Service

0:Boolean

0:PropertyType

M

0:HasProperty

Variable

Status_Flags

BACnetStatusFlags

0:PropertyType

M

0:HasProperty

Variable

Resolution

0:Float

0:PropertyType

O

0:HasProperty

Variable

COV_Increment

0:Float

0:PropertyType

O

0:HasComponent

Object

EventReporting

BACnetEventReportingType

O

0:HasComponent

Object

FaultEvaluation

BACnetFaultEvaluationType

O

The BACnetAnalogType is an abstract type and cannot be used directly.

The components of the BACnetAnalogType have additional subcomponents which are defined in Table 13.

Table 13 – BACnetAnalogType Additional Subcomponents

BrowsePath

References

NodeClass

BrowseName

DataType

TypeDefinition

Others

EventReporting

0:HasComponent

Object

EventAlgorithm

BACnetOutOfRangeAlgorithmType

M

This OPC UA Variable, of DataType Float, indicates the current value, in engineering units, of the input being measured. The Present_Value Variable shall be writable when Out_Of_Service is true.

This OPC UA AnalogItemType Variable represents the BACnet properties Present_Value, Min_Pres_Value, Max_Pres_Value, Units and Update_Interval. The OPC UA VariableType AnalogItemType is defined in OPC 10000-8. It defines the OPC UA Properties EURange, EngineeringUnits and InstrumentRange.

The following list provides the BACnet property and the mapping to the corresponding data member in the OPC UA AnalogItem.

This OPC UA Property, of DataType Boolean, represents the BACnet property Out_Of_Service.

It is an indication of whether or not the physical input that the object represents is not in service. While Out_Of_Service is True, Present_Value and Reliability may be changed to any value as a means of simulation and/or testing.

This OPC UA Property, of DataType BACnetStatusFlags, represents the BACnet property Status_Flags. The BACnetStatusFlags DataType is defined in 10.3.7.

It represents four Boolean flags that represent the general health of a BACnetAnalogType. The flags are IN_ALARM, FAULT, OVERRIDDEN, and OUT_OF_SERVICE.

This OPC UA Property, of type Float, represents the BACnet property COV_Increment.

It shall specify the minimum change in the BACnet property Present_Value that will cause a Change of Value notification to be issued to BACnet clients that have subscribed to Change of Value events.

This OPC UA Property, of DataType Float, represents the BACnet property Resolution.

It indicates the smallest recognizable change in Present_Value in engineering units.

The EventReporting Object contains status and configuration information for the event reporting of BACnetAnalogTypes and their subtypes. The BACnetEventReportingType is defined in 8.8. The Object is optional and is not present if event generation is not activated for the BACnet object.

The instance declaration Object EventReporting overrides definitions of the BACnetEventReportingType.

The EventAlgorithm component is changed to TypeDefinition BACnetOutOfRangeAlgorithmType and ModellingRule Mandatory if used in the BACnetAnalogType or one of its subtypes. The BACnetOutOfRangeAlgorithmType is defined in 8.9.3.

On the EventAlgorithm instance of the BACnetOutOfRangeAlgorithmType the BACnet property High_Limit is mapped to pHighLimit, the BACnet property Low_Limit is mapped to LowLimit, the BACnet property Deadband is mapped to pDeadband and the BACnet property Limit_Enable is mapped to LimitEnable.

The FaultEvaluation Object contains status and configuration information for the fault evaluation of the BACnetAnalogType. The BACnetFaultEvaluationType is defined in 8.23. The Object is optional and is not present if fault evaluation is not activated for the BACnet object.