A UANodeis an abstract base type for all Nodes. It defines the base set of Attributesand the References. There are subtypes for each NodeClassdefined in OPC 10000-4. Each of these subtypes defines XML elements and attributes for the OPC UA Attributesspecific to the NodeClass. The fields in the UANodetype are defined in Table F.2.

Table F.2– UANode

Element

Type

Description

NodeId

NodeId

A NodeIdserialized as a String.

The syntax of the serialized Stringis defined in 5.3.1.10.

BrowseName

QualifiedName

A QualifiedNameserialized as a Stringwith the form:

<namespace index>:<name>

Where the NamespaceIndexrefers to the NamespaceUristable.

SymbolicName

String

A symbolic name for the Nodethat can be used as a class/field name in auto generated code. It should only be specified if the BrowseNamecannot be used for this purpose.

This field does not appear in the AddressSpaceand is intended for use by design tools. Only letters, digits or the underscore (‘_’) are permitted.

WriteMask

WriteMask

The value of the WriteMaskAttribute.

UserWriteMask

WriteMask

Still in schema but no longer used.

AccessRestrictions

AccessRestrictions

The AccessRestrictionsthat apply to the Node.

DisplayName

LocalizedText []

A list of DisplayNamesfor the Nodein different locales.

There shall be only one entry per locale.

Description

LocalizedText []

The list of the Descriptionsfor the Nodein different locales.

There shall be only one entry per locale.

Category

String []

A list of identifiers used to group related UANodes together for use by tools that create/edit UANodeSet files.

Documentation

String

Additional non-localized documentation for use by tools that create/edit UANodeSet files.

References

Reference []

The list of Referencesfor the Node.

RolePermissions

RolePermissions []

The list of RolePermissionsfor the Node.

Extensions

xs:any

An element containing any vendor defined extensions to the UANode.

The Extensionsare free form XML data that can be used to attach vendor defined data to the UANode.

Array values are denoted with [], however, in the XML Schema arrays are mapped to a complex type starting with the ‘ListOf’ prefix.

A UANodeSetis expected to contain many UANodeswhich reference each other. Tools that create UANodeSetsshould not add Referenceelements for both directions in order to minimize the size of the XML file. Tools that read the UANodeSetsshall automatically add reverse references unless reverse references are not appropriate given the ReferenceTypesemantics. HasTypeDefinitionand HasModellingRuleare two examples where it is not appropriate to add reverse references.

Note that a UANodeSetrepresents a collection of Nodesin an address space. This implies that any instances shall include the fully inherited InstanceDeclarationHierarchyas defined in OPC 10000-3.