9.2.3.4.2 Mapping of structure data types
Ctrl servers shall support the binary encoding (“Default Binary”). Additionally, other encodings may be provided (not shown in above figure). Since OPC UA V1.04 a structured DataType provides the new attribute DataTypeDefinition. This attribute is defined in OPC 10000-6 – F.12. Implementations shall use this new attribute instead of the deprecated DataTypeDictionary.
A Server provides on a structured DataType Node the DataTypeDefinition attribute describing all elements and their order in this structure.
The Value of the DataTypeDefinition Attribute for a DataType Node describing ExampleIEC611313Structure is shown in Table 32.
| Name | Type | Description |
| defaultEncodingId | NodeId | NodeId of the “ExampleIEC611313Structure_Encoding_DefaultBinary” Node. |
| baseDataType | NodeId | “i=22” [Structure] |
| structureType | StructureType | Structure_0 [Structure without optional fields] |
| fields [0] | StructureField | |
| name | String | “IntStructureElement” |
| description | LocalizedText | Description of IntStructureElement |
| dataType | NodeId | “i=4” [Int16] |
| valueRank | Int32 | -1 (Scalar) |
| isOptional | Boolean | False |
| fields [1] | StructureField | |
| Name | String | “RealStructureElement“ |
| Description | LocalizedText | Description of RealStructureElement |
| dataType | NodeId | “i=10” [Float] |
| valueRank | Int32 | -1 (Scalar) |
| isOptional | Boolean | false |
| fields [2] | StructureField | |
| name | String | “BoolStructureElement“ |
| description | LocalizedText | Description of BoolStructureElement |
| dataType | NodeId | “i=1” [Boolean] |
| valueRank | Int32 | -1 (Scalar) |
| isOptional | Boolean | false |