Nodedefinitions are specified using tables (See Table 1)
Table 1– Type Definition Table
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Attribute |
Value |
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Attribute name |
Attribute value. If it is an optional Attribute that is not set “--“ will be used. |
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References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
ModellingRule |
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ReferenceTypename |
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. |
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Notes – Notes referencing footnotes of the table content. |
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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 an unknown size. If no number is provided at all the ArrayDimensionsmay 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
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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 |
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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 |
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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 |
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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 |
- The TypeDefinition is specified for Objectsand Variables.
- The TypeDefinition column specifies a NodeIdof a TypeDefinitionNode, i.e. the specified Nodepoints with a HasTypeDefinition Referenceto the corresponding TypeDefinitionNode. The symbolic name of the NodeId is used in the table.
- The ModellingRuleof the referenced component is provided by specifying the symbolic name of the rule in the ModellingRulecolumn. In the AddressSpace, the Nodeshall use a HasModellingRule Referenceto point to the corresponding ModellingRule Object.
If the NodeIdof a DataTypeis provided, the symbolic name of the Noderepresenting the DataTypeshall be used.
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, DataTypeand ModellingRulecan be derived from the type definitions, and the symbolic name can be created as defined in 4.3.2.1. Therefore those containing components are not explicitly specified; they are implicitly specified by the type definitions.