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.

• Present_Value represented by Value Attribute of the Variable.
• Min_Pres_Value represented by Low part of EURange Property of the Variable. If the optional BACnet property Min_Pres_Value is not present, the EURange Property should not be provided.
• Max_Pres_Value represented by the High part of EURange Property of the Variable. If the optional BACnet property Max_Pres_Value is not present, the EURange Property should not be provided.
• Units represented by the EngineeringUnits Property of the Variable. The mapping of BACnet units to OPC UA units is defined in 11.
• Update_Interval represented by MinSamplingInterval Attribute of the Variable.