The HasDescription ReferenceTypeis a concrete ReferenceTypeand can be used directly. It is a subtype of NonHierarchicalReferences.

The semantic of this ReferenceTypeis to reference the DataTypeDescriptionof a DataTypeEncoding.

The SourceNodeof Referencesof this type shall be an Objectof the ObjectType DataTypeEncodingType or one of its subtypes.

The TargetNodeof this ReferenceTypeshall be a Variableof the VariableType DataTypeDescriptionTypeor one of its subtypes.

Its representation in the AddressSpaceis specified in Table D.1.

Table D.1 – HasDescription ReferenceType

Attributes

Value

BrowseName

HasDescription

InverseName

DescriptionOf

Symmetric

False

IsAbstract

False

References

NodeClass

BrowseName

Comment

The DataTypeDictionaryType VariableTypeis used as the type for the DataTypeDictionaries. It is formally defined in Table D.2.

Table D.2 – DataTypeDictionaryType Definition

Attribute

Value

BrowseName

DataTypeDictionaryType

IsAbstract

False

ValueRank

−1 (−1 = Scalar)

DataType

ByteString

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the BaseDataVariableType defined in 7.4.

HasProperty

Variable

DataTypeVersion

String

PropertyType

Optional

HasProperty

Variable

NamespaceUri

String

PropertyType

Optional

HasProperty

Variable

Deprecated

Boolean

Property Type

Optional

The Property DataTypeVersionis explained in D.3.

The NamespaceUriis the URI for the namespace described by the Value Attributeof the DataTypeDictionary. This is not always the same as the NamespaceUriof the DataType NodeId.

The Deprecated Propertyis used to indicate that all of the DataTypedefinitions represented by the DataTypeDictionaryTypeare available through a DataTypeDefinition Attribute. Servers that provide DataTypedefinitions as a DataTypeDefinition Attributeand through a DataTypeDictionaryTypeshall expose this Property.

The DataTypeDescriptionType VariableTypeis used as the type for the DataTypeDescriptions. It is formally defined in Table D.3.

Table D.3 – DataTypeDescriptionType Definition

Attribute

Value

BrowseName

DataTypeDescriptionType

IsAbstract

False

ValueRank

-1 (-1 = Scalar)

DataType

String

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the BaseDataVariableType defined in 7.4.

HasProperty

Variable

DataTypeVersion

String

PropertyType

Optional

HasProperty

Variable

DictionaryFragment

ByteString

PropertyType

Optional

The PropertiesDataTypeVersion and DictionaryFragment are explained in D.3.

The DataTypeSystems ObjectTypeis used as type for the DataTypeSystems. There are no Referencesspecified for this ObjectType. It is formally defined in Table D.4.

Table D.4 – DataTypeSystemType Definition

Attribute

Value

BrowseName

DataTypeSystemType

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the BaseObjectType defined in 6.2.

OPC Binary is a standard DataTypeSystemdefined by OPC. It is represented in the AddressSpaceby an Object Node. The OPC Binary DataTypeSystemis defined in OPC 10000-3. OPC Binary uses XML to describe complex binary data values. The “OPC BinaryObjectis formally defined in Table D.5.

Table D.5 – OPC Binary Definition

Attribute

Value

BrowseName

OPC Binary

References

NodeClass

BrowseName

Comment

HasTypeDefinition

ObjectType

DataTypeSystemType

Defined in D.5.4

XML Schema is a standard DataTypeSystemdefined by the W3C. It is represented in the AddressSpaceby an Object Node. XML Schema documents are XML documents whose xmlns attribute in the first line is:

schema xmlns =http://www.w3.org/1999/XMLSchema

The “XML SchemaObjectis formally defined in Table D.6.

Table D.6 – XML Schema Definition

Attribute

Value

BrowseName

XML Schema

References

NodeClass

BrowseName

Comment

HasTypeDefinition

ObjectType

DataTypeSystemType

Defined in D.5.4