Class

• <DRM Property Characteristic>

Superclass

• <DRM SEDRIS Abstract Base>

Subclass

• None.

Definition

An instance of this DRM class specifies additional information about how to use, interpret or further specify a <DRM Property> subclass. It consists of an enumeration that designates the type of information, and a value for the designated attribute.

The meaning field specifies the semantic represented by the given <DRM Property Characteristic> instance.

The characteristic_value field specifies the data value of the given <DRM Property Characteristic> instance.

Class diagram

Figure 6.220 — DRM_Property_Characteristic

Constraints

• Property Characteristic restrictions
• Publishable Object

Example(s)

• A <DRM Model> instance classified as ECC_BRIDGE has a <DRM Property Value> instance representing its length. The <DRM Property Value> instance has two <DRM Property Characteristic> components to specify maximum length and length precision:

  The first <DRM Property Characteristic> component specifies:

  meaning = EVC_MAXIMUM_VALUE
  characteristic_value =
    (attribute_value_type = REAL,
     real_value =
       (unit = EUC_METRE,
        unit_scale = ESC_UNI,
        value = 32767,0))

  The second <DRM Property Characteristic> component specifies:

  meaning = EVC_TOLERANCE
  characteristic_value =
    (attribute_value_type = REAL,
     real_value =
       (unit = EUC_METRE,
        unit_scale = ESC_UNI,
        value = 1,0))

• A <DRM Property Grid> instance containing a <DRM Table Property Description> instance with

  meaning = { ATTRIBUTE, { EAC_AIR_TEMPERATURE }}

  describes air temperature measurements over the specified region. In some locations, no measurements were taken, so a sentinel value (deliberately chosen to lie outside the range of possible data values) is needed to indicate those locations.

  Consequently, the <DRM Table Property Description> instance for EAC_AIR_TEMPERATURE in this example has a <DRM Property Characteristic> instance with meaning = EVC_MISSING and characteristic_value of, for example, -10000.

  Any cell data element for this <DRM Table Property Description> instance that has a value of -10000 is therefore interpreted as meaning that the measurement is missing.

  The <DRM Table Property Description> instance may have other <DRM Property Characteristic> components, provided that they have different meaning values. For example, this <DRM Table Property Description> instance may have another <DRM Property Characteristic> instance specifying EVC_MINIMUM_VALUE.

• A <DRM Property Grid> instance containing a <DRM Table Property Description> instance with

  meaning = { ATTRIBUTE, { EAC_SALINITY }}

  describes water salinity data over the region specified for the grid. However, in this example, part of the grid lies over land, so that water salinity measurements not only were not taken there, but make no sense. A sentinel value (deliberately chosen to lie outside the range of possible data values) is needed to indicate those locations.

  Consequently, the <DRM Table Property Description> instance for EAC_SALINITY in this example has a <DRM Property Characteristic> instance with meaning = EVC_NOT_APPLICABLE and a characteristic_value of, for example, -1.

  Any cell data element for this <DRM Table Property Description> instance that has a value of -1 is therefore interpreted as meaning that the measurement is not applicable.

  The <DRM Table Property Description> instance may have other <DRM Property Characteristic> components provided that they have different meaning values. For example, this <DRM Table Property Description> instance may have another <DRM Property Characteristic> instance specifying EVC_MINIMUM_VALUE.