Referencing External Libraries from STEP Application Protocols

1
Referencing External Libraries from STEP
Application Protocols

• Gerry Radack
• Open Technical Forum
• 2002-11-04

2
Background

• QC N068 Interpretation of PLIB services is the
  basis for referencing PLIB data from STEP APs
• Used in several STEP APs
• AP 212, 214, 227, ...
• AP 212 was developed with the expectation that it
  would be used with the IEC 61360 PLIB-compliant
  dictionary
• Based on ISO 13584 concepts and terminology
• Identifies four services

3
Data Model
supplier

class
property


instance
representation

4
Service 1

• The classification of a piece of product data
  that is a part, a material, a feature etc. is
  provided as reference data
• In order to use this service, the following must
  be identified
• library supplier
• class
• class version

5
Service 2

• The definition of a property of a piece of
  product data that is a part, a material, a
  feature etc. is provided as reference data
• In order to use this service, the following must
  be identified
• library supplier
• class
• class version
• property
• property version

6
Service 3

• A piece of product data that is a part, a
  material, a feature etc. itself is defined as
  reference data
• In order to use this service, the following must
  be identified
• library supplier
• class
• class version
• the instance of the class
• can be given as a set of property-value pairs
• property
• property version
• value

7
Service 4

• The representation (of a piece of product data
  that is a part, a material, a feature etc.) is
  defined (e.g., parametrically) as reference data
• In order to use this service, the following must
  be provided
• library supplier
• class
• class version
• the instance of the class
• can be given as a set of property-value pairs
• the location and orientation (for a geometric
  rep.)

8
Library Supplier

• ISO 13584-026 defines an encoding for identifying
  information suppliers
• Based on ISO/IEC 6523-11998, Information
  technology Structure for the identification of
  organizations and organization parts Part 1
  Identification of organization identification
  schemes

9
Current Activities

• T23 is exploring the use of AP 227 ed. 2 RDL to
  satisfy the requirements for ship mechanical
  systems

10
Observations

• Reference data have existed implicitly in STEP
  from the beginning

11
Example

• stream_phase lt
• property_definition
• represented_definition property_definition
• represented_definition lt-property_
• definition_representation.definition
• property_definition_representation
• property_definition_representation.used_representa
  tion -gt
• representation
• representation.name 'stream phase
  characteristics'
• representation
• (representation.itemsi -gt
• representation_item
• (representation_item.name 'temperature')
• (representation_item.name 'maximum temperature')

• (representation_item.name 'minimum
  temperature'))
• (representation.itemsi -gt
• representation_item
• representation_item.name 'maximum
  temperature'
• representation.itemsi -gt
• representation_item
• representation_item.name 'minimum
  temperature')
• representation_item gt
• measure_representation_item lt
• measure_with_unit gt
• thermodynamic_temperature_measure_with_unit
• measure_with_unit
• measure_with_unit.value_component
• measure_with_unit.unit_component

12
Example

• /PROD_CAT_NAME(navy ship)/
• product_category lt-product_
• category_relationship.category
• product_category_relationship
• product_category_relationship.name 'navy ship
  types
• product_category_relationship.category -gt
• product_category
• product_category_relationship
• product_category_relationship.sub_category -gt
• product_category
• (product_category.name Aircraft carrier)
• (product_category.name Corvette)
• (product_category.name Cruiser)

• (product_category.name Destroyer)
• (product_category.name Fleet auxiliary
  vessel)
• (product_category.name Frigate)
• (product_category.name Mine warfare ship)
• (product_category.name Patrol force vessel)
• (product_category.name Service craft)
• (product_category.name Submarine)
• (product_category.name Auxiliary oiler)
• (product_category.name Landing platform dock)
• (product_category.name Landing platform
  helicopter)
• (product_category.name user defined)

13
Issues

• Mechanism for identifying supplier
• Additional services?
• Additional requirements for referencing RDL data?
• Identification of data in different versions of
  the RDL
• Supplier identification
• Use of class/property versioning scheme
• Need for a library reference module