The HasDescription ReferenceType is a concrete ReferenceType and can be used directly. It is a subtype of NonHierarchicalReferences.

The semantic of this ReferenceType is to reference the DataTypeDescription of a DataTypeEncoding.

The SourceNode of References of this type shall be an Object of the ObjectType DataTypeEncodingType or one of its subtypes.

The TargetNode of this ReferenceType shall be a Variable of the VariableType DataTypeDescriptionType or one of its subtypes.

Its representation in the AddressSpace is 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 VariableType is 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 DataTypeVersion is explained in D.3.

The NamespaceUri is the URI for the namespace described by the Value Attribute of the DataTypeDictionary. This is not always the same as the NamespaceUri of the DataType NodeId.

The Deprecated Property is used to indicate that all of the DataType definitions represented by the DataTypeDictionaryType are available through a DataTypeDefinition Attribute. Servers that provide DataType definitions as a DataTypeDefinition Attribute and through a DataTypeDictionaryType shall expose this Property.

The DataTypeDescriptionType VariableType is 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 Properties DataTypeVersion and DictionaryFragment are explained in D.3.

The DataTypeSystems ObjectType is used as type for the DataTypeSystems. There are no References specified 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 DataTypeSystem defined by OPC. It is represented in the AddressSpace by an Object Node. The OPC Binary DataTypeSystem is defined in OPC 10000-3. OPC Binary uses XML to describe complex binary data values. The “OPC BinaryObject is 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 DataTypeSystem defined by the W3C. It is represented in the AddressSpace by 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 SchemaObject is 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