Nodedefinitions are specified using tables (See Table 1)

Table 1– Type Definition Table

Name

Value

Attribute name

Attribute value. If it is an optional Attribute that is not set “--“ will be used.

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

ReferenceTypename

NodeClassof the TargetNode.

BrowseNameof the target Node. If the Referenceis to be instantiated by the server, then the value of the target Node’s BrowseName is “--“.

Attributesof the referenced Node, only applicable for Variablesand Objects.

Referenced ModellingRuleof the referenced Object.

Notes –

Notes referencing footnotes of the table content.

Attributesare defined by providing the Attributename and a value, or a description of the value.

Referencesare defined by providing the ReferenceTypename, the BrowseNameof the TargetNodeand its NodeClass.

  • If the TargetNodeis a component of the Nodebeing defined in the table the Attributesof the composed Nodeare defined in the same row of the table. That implies that the referenced Nodehas a HasModelParent Referencewith the Nodedefined in the Table as TargetNode (see OPC 10000-3for the definition of ModelParents).
  • The DataTypeis only specified for Variables; “[<number>]” indicates a single-dimensional array, for multi-dimensional arrays the expression is repeated for each dimension (e.g. [2][3] for a two-dimensional array). For all arrays the ArrayDimensionsis set as identified by <number> values. If no <number> is set, the corresponding dimension is set to 0, indicating an unknown size. If no number is provided at all the ArrayDimensionscan be omitted. If no brackets are provided, it identifies a scalar DataTypeand the ValueRankis set to the corresponding value (see OPC 10000-3). In addition, ArrayDimensionsis set to null or is omitted. If it can be Any or ScalarOrOneDimension, the value is put into “{<value>}”, so either “{Any}” or “{ScalarOrOneDimension}” and the ValueRankis set to the corresponding value (see OPC 10000-3) and the ArrayDimensionsis set to null or is omitted. In Table 2examples are given.

Table 2– Examples of DataTypes

Notation

DataType

ValueRank

ArrayDimensions

Description

Int32

Int32

-1

omitted or NULL

A scalar Int32

Int32[]

Int32

1

omitted or {0}

Single-dimensional array of Int32 with an unknown size

Int32[][]

Int32

2

omitted or {0,0}

Two-dimensional array of Int32 with unknown sizes for both dimensions

Int32[3][]

Int32

2

{3,0}

Two-dimensional array of Int32 with a size of 3 for the first dimension and an unknown size for the second dimension

Int32[5][3]

Int32

2

{5,3}

Two-dimensional array of Int32 with a size of 5 for the first dimension and a size of 3 for the second dimension

Int32{Any}

Int32

-2

omitted or NULL

An Int32 where it is unknown if it is scalar or array with any number of dimensions

Int32{ScalarOrOneDimension}

Int32

-3

omitted or NULL

An Int32 where it is either a single-dimensional array or a scalar

If the NodeIdof a DataTypeis provided, the symbolic name of the Noderepresenting the DataTypeshall be used.

Nodesof all other NodeClassescannot be defined in the same table; therefore only the used ReferenceType, their NodeClassand their BrowseNameare specified. A reference to another of this document points to their definition.

If no components are provided, the DataType, TypeDefinition and ModellingRule columns may be omitted and only a Comment column is introduced to point to the Nodedefinition.

Components of Nodescan be complex, i.e. containing components by themselves. The TypeDefinition, NodeClass, DataType and ModellingRule can be derived from the type definitions, and the symbolic name can be created as defined in 3.4.2.1. Therefore those containing components are not explicitly specified; they are implicitly specified by the type definitions.

The NodeIdsof all Nodesdescribed in this document are only symbolic names. Annex Adefines the actual NodeIds.

The symbolic name of each Nodedefined in this document is its BrowseName, or, when it is part of another Node, the BrowseNameof the other Node, a “.”, and the BrowseNameof itself. In this case “part of” means that the whole has a HasPropertyor HasComponent Referenceto its part. Since all Nodesnot being part of another Nodehave a unique name in this document, the symbolic name is unique.

The namespace for this specification is defined in Annex A. The NamespaceIndex for all NodeIdsdefined in this specification is server specific and depends on the position of the namespace URI in the server namespace table.

Note: This specification does not only define concrete Nodes, but also requires that some Nodes have to be generated, for example one for each device type available in the frame application. The NodeIdsof those Nodesare server-specific, including the Namespace. But the NamespaceIndex of those Nodescannot be the NamespaceIndex used for the Nodes defined by this specification, because they are not defined by this specification but generated by the Server.

The text part of the BrowseNamesfor all Nodesdefined in this specification is specified in the tables defining the Nodes. The NamespaceIndex for all BrowseNamesdefined in this specification is server specific and depends on the position of the namespace URI defined in this specification in the server namespace table.

If the BrowseName is not defined by this specification, a namespace index prefix like ‘0:EngineeringUnits’ is added to the BrowseName. This is typically necessary if a Property of another specification is overwritten or used in the OPC UA types defined in this specification. Table 81provides a list of namespaces used in this specification.

For all Nodesspecified in this specification, the Attributesnamed in Table 3shall be set as specified in the table.

Table 3– Common Node Attributes

Attribute

Value

DisplayName

The DisplayNameis a LocalizedText. Each server shall provide the DisplayNameidentical to the BrowseNameof the Nodefor the LocaleId “en”. Whether the server provides translated names for other LocaleIds is vendor specific.

Description

Optionally a vendor specific description is provided

NodeClass

Shall reflect the NodeClassof the Node

NodeId

The NodeIdis described by BrowseNamesas defined in 3.4.2.1and defined in Annex A.

WriteMask

Optionally the WriteMask Attributecan be provided. If the WriteMask Attributeis provided, it shall set all Attributesto not writeable that are not said to be vendor-specific. For example, the Description Attributemay be set to writeable since a Server may provide a server-specific description for the Node. The NodeIdshall not be writeable, because it is defined for each Nodein this specification.

UserWriteMask

Optionally the UserWriteMask Attributecan be provided. The same rules as for the WriteMask Attributeapply.

For all Objectsspecified in this specification, the Attributesnamed in Table 4shall be set as specified in the table.

Table 4– Common Object Attributes

Attribute

Value

EventNotifier

Whether the Nodecan be used to subscribe to Eventsor not is vendor specific

For all Variablesspecified in this specification, the Attributesnamed in Table 5shall be set as specified in the table.

Table 5– Common Variable Attributes

Attribute

Value

MinimumSamplingInterval

Optionally, a vendor-specific minimum sampling interval is provided

AccessLevel

The access level for Variablesused for type definitions is vendor-specific, for all other Variablesdefined in this part, the access level shall allow a current read; other settings are vendor specific.

UserAccessLevel

The value for the UserAccessLevel Attributeis vendor-specific. It is assumed that all Variablescan be accessed by at least one user.

Value

For Variablesused as InstanceDeclarations,the value is vendor-specific; otherwise it shall represent the value described in the text.

ArrayDimensions

If the ValueRankdoes not identify an array of a specific dimension (i.e. ValueRank<= 0) the ArrayDimensionscan either be set to null or the Attributeis missing. This behaviour is vendor-specific.

If the ValueRankspecifies an array of a specific dimension (i.e. ValueRank> 0) then the ArrayDimensions Attributeshall be specified in the table defining the Variable.

For all VariableTypesspecified in this specification, the Attributesnamed in Table 6shall be set as specified in the table.

Table 6– Common VariableType Attributes

Attributes

Value

Value

Optionally a vendor-specific default value can be provided

ArrayDimensions

If the ValueRankdoes not identify an array of a specific dimension (i.e. ValueRank<= 0) the ArrayDimensionscan either be set to null or the Attributeis missing. This behaviour is vendor-specific.

If the ValueRankspecifies an array of a specific dimension (i.e. ValueRank> 0) then the ArrayDimensions Attributeshall be specified in the table defining the VariableType.