Using STEP in exchange of digital product information.

Ing. Martin Molhanec, CSc.

What is STEP?

Maybe?

No ! The STEP is

STandard for Exchange of Production 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 MethodsExplain how to describe the REAL

WORLD – the production data.Based on software engineering

analytics methods.Object Oriented paradigma.EXPRESS language (ISO 10303-11).

Example of descriptionSCHEMA 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 10303 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 formatISO-10303-21;HEADER;/*----------------------------------------* Exchange File generated by ST-DEVELOPER v1.4* Conforms to ISO 10303-21*/FILE_DESCRIPTION ((''), '1');FILE_NAME ('materials_data', '1996-07-01T12:13:37-

04:00',(''), (''), 'ST-DEVELOPER v1.4', '', '');FILE_SCHEMA (('MATERIALS'));ENDSEC;DATA;#10 = LINEAR_MATERIAL ('Alumina', $ , 0.0000067, $

, $ , $, $ );#20 = LINEAR_MATERIAL ('Ceramic', $ , 0.0000003, $

, $ , $, $ );ENDSEC;END-ISO-10303-21;

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 2

166 27 PRAHA 6

Tel:. ++420 (2) 2435 2118

Email: molhanec@fel.cvut.cz

WWW: http://martin.feld.cvut.cz/~mmm