PDM-UG: Document Identification Context Information
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This page belongs to the PDM Usage Guide.
Context information provides a scope and necessary circumstance for product identification information. It consists of two separate and related areas:
- Application Protocol Identification,
- Application Context Information.
Application protocol identification and general context information are handled structurally the same for 'Document as Product', 'Part as Product', and product concept identification. A single instance of the entity application_context should be referenced by all product_context and product_concept_context entities, for parts, documents and product concepts. This application_context should be referenced by the single instance of the entity application_protocol_definition. The general context information identifies the usage of the information within the scope of the PDM Schema and the application domain which provides a basis for the interpretation of all information represented in the product data exchange.
The application context information is managed differently to distinguish documents from parts:
- Life-cycle information does not have to be maintained for 'Document as Product', as it is for 'Part as Product' to identify the development life-cycle stages. When a managed document is assigned to a part master, the life-cycle stage of the part master identification may be extrapolated as relevant to the document;
- To distinguish a document representation view definition, the names 'digital document definition' or 'physical document definition' are used, as differentiated from the value 'part definition' used in 'Part as Product'. A digital document definition represents an electronic document, while a physical document definition stands for a 'hardcopy', typically paper, document.
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The Instance Model: EXPRESS entities and attributes
The EXPRESS entities and attributes used to support the requirements of document identification with context information are illustrated in Diagram 34.
Diagram 34: Document Master with Context Information Instance Diagram
Product definition
The product_definition entity denotes the definition of a particular view of a representation of a document version. There may be more than one document representation definition associated with a single document version. The representation view definition of a document version is used for association of document properties, to build document structures, or to associate a document with the set of constituent external files that make it up. The entity product_definition supports property association and document structure. The subtype product_definition_with_associated_documents is used to associate a representation of a document version with the set of constituent files that make it up.
Attributes
- The id attribute indicates the unique identifier of the document representation definition.
- The description attribute provides optional additional words describing the representation definition.
- The formation attribute references the document version of which this is a representation definition.
- The frame_of_reference attribute references the context information related to this definition.
| ENTITY product_definition | Attribute Population | Remarks |
| id | type : identifier = string | Must be unique in relation with a specific product_version |
| description | type: text | OPTIONAL |
| formation | type: entity = product_definition_formation | Document version of which this is a particular document representation definition |
| frame_of_reference | type : entity = product_definition_context | Context information for this definition. |
===Preprocessor Recommendations=== The value for the id attribute of product_definition should be unique relative to other product_definition entities related to the same product_definition_formation.
===Postprocessor Recommendations=== There are no specific postprocessor recommendations.
===Related Entities=== There are no specific related entities.
Product definition context
All STEP product_definitions must be defined in a product_definition_context. With 'Document as Product', the context information is used to distinguish digital from physical 'hardcopy' documents.
Attributes
- The name attribute indicates the type of the document representation definition.
- The frame_of_reference attribute references application domain information.
- The life_cycle_stage attribute has no standard mapping for documents in this usage guide.
| ENTITY product_definition_context | Attribute Population | Remarks |
| name | type: label = string 'digital document definition' or 'physical document definition' | Distinguishes the associated product_definition as that of a document |
| frame_of_reference | type: entity = application_context | |
| life_cycle_stage | type: label = text |
===Preprocessor Recommendations=== The name attribute distinguishes the representation definition of a document version as either digital ('digital document definition') or physical, i.e., hardcopy ('physical document definition').
===Postprocessor Recommendations=== Postprocessors should interpret the value of the name attribute as a distinction between part and document definitions, and further between digital and physical document definitions.
===Related Entities=== There are no specific related entities.
The Instance Model: STEP exchange file format (ISO10303 Part 21 syntax)
#240=APPLICATION_CONTEXT('');
#245=APPLICATION_PROTOCOL_DEFINITION('version 1.2','pdm_schema',2000,#240);
#250=PRODUCT_DEFINITION_CONTEXT('digital document definition',#240,'');
#260=PRODUCT_CONTEXT('',#240,'');
#270=PRODUCT('doc_4711','packaging guide','packaging guideline for part',(#260));
#280=PRODUCT_DEFINITION_FORMATION('ver3.1','version 3.1',#270);
#290=PRODUCT_DEFINITION('id of digital document','digital document for representing guideline 3.1',#280,#250);
