Nodedefinitions are specified using tables (see Table 2).
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 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. Examples are given in Table 1.
Table 1– Examples of DataTypes
|
Notation |
DataType |
ValueRank |
ArrayDimensions |
Description |
|
0:Int32 |
0:Int32 |
-1 |
omitted or null |
A scalar Int32. |
|
0:Int32[] |
0:Int32 |
1 |
omitted or {0} |
Single-dimensional array of Int32 with an unknown size. |
|
0:Int32[][] |
0:Int32 |
2 |
omitted or {0,0} |
Two-dimensional array of Int32 with unknown sizes for both dimensions. |
|
0:Int32[3][] |
0: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. |
|
0:Int32[5][3] |
0: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. |
|
0:Int32{Any} |
0:Int32 |
-2 |
omitted or null |
An Int32 where it is unknown if it is scalar or array with any number of dimensions. |
|
0:Int32{ScalarOrOneDimension} |
0: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 symbolic name for a NodeId, i.e. the specified Nodepoints with a HasTypeDefinition Referenceto the corresponding Node.
- 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.
Note that if a symbolic name of a different namespace is used, it is prefixed by the NamespaceIndex(see 3.3.2.2).
Nodesof all other NodeClassescannot be defined in the same table; therefore, only the used ReferenceType, their NodeClassand their BrowseNameare specified. A reference to another part of this document points to their definition.
Table 2illustrates the table. If no components are provided, the DataType, TypeDefinition and Other columns may be omitted and only a Comment column is introduced to point to the Nodedefinition.
Table 2– Type Definition Table
|
Attribute |
Value |
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|
Attribute name |
Attribute value. If it is an optional Attribute that is not set "--" is used. |
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|
|
|
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|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Other |
|
ReferenceTypename |
BrowseNameof the target Node. |
DataType of the referenced Node, only applicable for Variables. |
TypeDefinitionof the referenced Node, only applicable for Variablesand Objects. |
Additional characteristics of the TargetNodesuch as the ModellingRuleor AccessLevel. |
|
|
NOTE Notes referencing footnotes of the table content. |
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Components of Nodescan be complex that is containing components by themselves. The TypeDefinition, NodeClassand DataType can be derived from the type definitions, and the symbolic name can be created as defined in 3.3.3.1. Therefore, those containing components are not explicitly specified; they are implicitly specified by the type definitions.
The Other column defines additional characteristics of the Node. Examples of characteristics that can appear in this column are show in Table 3.
Table 3– Examples of Other Characteristics
|
Name |
Short Name |
Description |
|
0:Mandatory |
M |
The Nodehas the Mandatory ModellingRule. |
|
0:Optional |
O |
The Nodehas the Optional ModellingRule. |
|
0:MandatoryPlaceholder |
MP |
The Nodehas the MandatoryPlaceholder ModellingRule. |
|
0:OptionalPlaceholder |
OP |
The Nodehas the OptionalPlaceholder ModellingRule. |
|
ReadOnly |
RO |
The Node AccessLevelhas the CurrentReadbit set but not the CurrentWritebit. |
|
ReadWrite |
RW |
The Node AccessLevelhas the CurrentReadand CurrentWritebits set. |
|
WriteOnly |
WO |
The Node AccessLevelhas the CurrentWritebit set but not the CurrentReadbit. |
If multiple characteristics are defined they are separated by commas. The name or the short name may be used.