NullArea

Overview

Data type

A null value for a physical quantity of type NullableArea. The only instance of this singleton type is NULL_AREA.

Supertypes

• NullableArea

Implementation in Proteus Schema

All data attributes with type NullableArea (the base type of NullArea) are implemented as DEXPI generic attributes for physical quantities.

Example

Implementation in Proteus Schema

<GenericAttribute
  Format="double" ...>

Note that the <GenericAttribute> element must have a Name and an AttributeURI attribute. They depend on the data type attribute of the DEXPI class that owns the null instance NULL_AREA (e.g., see the implementation example for the attribute FilterArea of the DEXPI class FilterUnit). For a null value, the attributes Units, UnitsURI, and Value must not be used.