Nodedefinitions are specified using tables (See Table 1)

Table 1– Type Definition Table

Attribute

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 “--”.

Attributeof the referenced Node, only applicable for Variables.

TypeDefinition Nodeof 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.
  • 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 a dynamic size. If no number is provided at all the value is scalar and the ArrayDimensionsis 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 section of this specificationpoints 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.