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.
Element |
Type |
Description |
NodeId |
NodeId |
|
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.