Background Information

General

This clause provides general information about sources of information and relevant concepts for the data specification under consideration, as well as its usage in the context of the Asset Administration Shell. It is not normative.

Data Elements (Part 1)

Metamodel of Data Elements (Part 1)
Figure 1. Metamodel of Data Elements (Part 1)

The data specification template IEC61360 is relevant for the definition of concept descriptions for data elements (Figure 1). Submodel Elements inherit from hasSemantics, i.e. they have a semanticId and optionally some additional supplementary semantic IDs (Figure 2).

Figure Overview Relationship Metamodel Part 1 a & Data Specifications IEC 61360 gives an overview of the relationship of concept descriptions (ConceptDescription) and data specifications (DataSpecification, DataSpecificationContent and HasDataSpecification) from Part 1 for this concrete data specification template.

Metamodel of HasSemantics (Part 1)
Figure 2. Metamodel of HasSemantics (Part 1)

Clause Category of Concept Descriptions describes how to use the data specification template to describe further of the metamodel as specified in Part 1 that may also have semantics assigned to them (by inheriting from HasSemantics): Submodel, all other SubmodelElements, SpecificAssetId, Qualifier, and Extension. In these cases, the preferred name and the definition are mainly used to provide a minimum of information on what the corresponding value is about.

Examples

Figure 3 shows an example of a property with idShort "MaxRotationSpeed" with a semantic ID referring to a concept description "MaxRotationSpeed". The concept description shows that MaxRotationSpeed is a quantitative property because the data type is one of *_MEASURE, namely INTEGER_MEASURE. In this case, the definition of a physical unit is mandatory. It is "1/min" for MaxRotationSpeed. A unique ID is also provided for this physical unit. Concept descriptions for physical units are described e.g. in Part 4b of this document series on the Details of the Asset Administration Shell.

The type INTEGER_MEASURE of the concept description is mapped to xs:integer of the property.

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Figure 3. Example Quantitative Property MaxRotationSpeed in AASX Package Explorer

Figure 4 shows a property "CoolingType". Its semanticId references a concept description that defines a value list (DataSpecificationIec612360/valueList) with two values BAB657 and BAB611.

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Figure 4. Example Property with Enumeration in AASX Package Explorer

Figure 5 shows the concept description for the value BAB657 that was used in the enumeration in Figure 4. Most attributes are not relevant (see Clause Category of Concept Descriptions). However, it is mandatory to set the attribute DataSpecificationIec61360/value, the preferredName (open circuit, external cooling), and the data type (for enumeration, the data type is typically just STRING).

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Figure 5. Example Value Concept Description in AASX Package Explorer

Referencing (Part 1)

Besides the abstract class HasSemantics, the referencing concept explained in Part 1 is also relevant (Figure 6). In the case of the data specification template IEC61360, the only relevant key types are "GlobalReference" and "ConceptDescription". In case the concept description is a shadow copy of an existing data dictionary and uses the same ID, it is recommended to use the Global Reference for the DataSpecificationIec61360/unitId or ValueReferencePair/valueId. Otherwise, a model reference with Key/type equal to ConceptDescription is used.

The same applies to HasSemantics/semanticId and semantic IDs in HasSemantics/supplementalSemanticIds.

Metamodel of Reference (Part 1)
Figure 6. Metamodel of Reference (Part 1)