Using STEP in exchange of digital product information. Ing. Martin Molhanec, CSc.

What is STEP?

Maybe?

No ! The STEP is   ST andard for E xchange of P roduction data.  It is the ISO standard (ISO 10303).  The STEP standard is supporting geometry, topology, relationship, attributes, assemblies and configuration of product management data.

The STEP has many parts.

Description Methods  Explain how to describe the REAL WORLD – the production data.  Based on software engineering analytics methods.  Object Oriented paradigma.  EXPRESS language (ISO ).

Example of description SCHEMA materials; ENTITY linear_material; name : STRING; young_modulus : REAL; coef_thermal_expansion : REAL; shear_modulus : REAL; yield_stress : REAL; ultimate_stress : REAL; poissons_ratio : REAL; END_ENTITY; END_SCHEMA (* materials *);

Implementation Methods  Describe the mapping from STEP formal specifications (EXPRESS language) to a representation used to implement STEP  At present time exist following ISO parts: 21 (STEP file format) 22 (Abstract STEP Data Access Interface – SDAI) 27 (Java™ language-based SDAI) 28 (STEP data in XML) products are under development

STEP file format ISO ; HEADER; /* * Exchange File generated by ST-DEVELOPER v1.4 * Conforms to ISO */ FILE_DESCRIPTION ((''), '1'); FILE_NAME ('materials_data', ' T12:13:37-04:00', (''), (''), 'ST-DEVELOPER v1.4', '', ''); FILE_SCHEMA (('MATERIALS')); ENDSEC; DATA; #10 = LINEAR_MATERIAL ('Alumina', $, , $, $, $, $ ); #20 = LINEAR_MATERIAL ('Ceramic', $, , $, $, $, $ ); ENDSEC; END-ISO ;

Application Protocols  The STEP Parts known as Application Protocols (AP’s, part series 2xx) define formal models in a designated application area.  Some examples of protocols –AP203: Configuration controlled design –AP210: Electronic assembly, interconnect and packaging design –AP212: (Electrotechnical design and installation)

EXPRESS language  Object oriented  Human readable  Computer interpretable  Overall structure is similar to OOPL (object oriented program language )  Data model is similar to ERM (Entity- relationship model )

EXPRESS language  EXPRESS-C (EXPRESS with static and behavioural modelling capabilities)  EXPRESS-G (Graphical language)  EXPRESS-I (Instantiation language)  EXPRESS-M (Mapping definition language)  EXPRESS-P (Process definition language)  EXPRESS-V (Extension of EXPRESS which enables the creation of views)  EXPRESS-X (Merger of M and V)

Example of EXPRESS-G (Graphical language)

Simple example

EXPRESS language (description of point) ENTITY Point; x: REAL; y: REAL; END_ENTITY;

EXPRESS language (description of 3D point) ENTITY Point3D SUBTYPE OF (Point); z : REAL; END_ENTITY;

EXPRESS/STEP tools  WinSTEP (Version 3.0) –University of the Federal Armed Forces  J-SDAI –LKSoftWare GmbH  NIST Expresso –National Institute for Standards and Technology  EzExpress –free

EzExpress (editor for STEP definition files)

JSDAI STEP – Book AP210

CONCLUSION  The aim of this article was a brief explanation of STEP standard and EXPRESS language.  The STEP standard is the most important development in the area of an exchange of production data between different producers.  The STEP standard is supported by U.S.A. government and many of the most major worldwide producers e.g. General Electric, etc.

CONCLUSION  Our projects in the area of using the STEP/EXPRESS standard. –educational  put basic information about this standard in the courses –research  using the STEP/EXPRESS standard in the area of the packaging

Ing. Martin Molhanec, CSc. Czech Technical University Faculty of Electrical Engineering Department of Electrotechnology Technicka PRAHA 6 Tel: (2) WWW: