STEP Tutorial: “ How a Software Developer Implements STEP” Tony Ranger, Theorem Solutions January 16, 2001 ® PDES, Inc.

Copyright PDES, Inc ® Who am I ? A “developer” develops the standard An “implementor” implements the developed standard A “user” uses the implemented standard I am an implementor (I know my place!)

PDES, Inc. Copyright PDES, Inc ® What is STEP ? A Neutral Format for Product Data An International Standard - ISO A Computer Interpretable Definition Designed to avoid known problems and limitations of IGES Designed to have the capability of covering the full range of product data

PDES, Inc. Copyright PDES, Inc ® A Neutral Format #1723=CARTESIAN_POINT(“PT1”,(1.0,2.0,3.0));

PDES, Inc. Copyright PDES, Inc ® A Computer Interpretable Definition : Part 21 #1723=CARTESIAN_POINT(“PT1”,(1.0,2.0,3.0)); ENTITY_INSTANCE = ENTITY_INSTC_NAME “=“ SIMPLE_RECORD “;” ENTITY_INSTC_NAME = “#” DIGIT [DIGIT [DIGIT [DIGIT [DIGIT [DIGIT [DIGIT [DIGIT [DIGIT [DIGIT ]]]]]]]. [DIGIT [DIGIT [DIGIT [DIGIT [DIGIT [DIGIT ]]]]]]]. SIMPLE_RECORD = KEYWORD “(“ [ PARAMETER_LIST ] “)”

PDES, Inc. Copyright PDES, Inc ® A Computer Interpretable Definition : Express #1723=CARTESIAN_POINT(“PT1”,(1.0,2.0,3.0)); ENTITY cartesian_point SUBTYPE OF (point); coordinates : LIST[1:3] OF length_measure; END_ENTITY; ENTITY point SUPERTYPE OF (cartesian_point) SUBTYPE OF (geometric_representation_item); END_ENTITY;

PDES, Inc. Copyright PDES, Inc ® A Computer Interpretable Definition : Express (2) ENTITY geometric_representation_item SUPERTYPE OF (ONEOF(point,direction,vector,placement, etc)) SUBTYPE OF (representation_item); DERIVE dim : dimension_count := dimension_of(SELF); WHERE wr1 : SIZEOF(QUERY(using_rep <* using_representations(SELF) | NOT ( 'PDM_SCHEMA.GEOMETRIC_REPRESENTATION_CONTEXT' IN TYPEOF(using_rep.context_of_items)))) = 0; END_ENTITY;

PDES, Inc. Copyright PDES, Inc ® A Computer Interpretable Definition : Express (3) #1723=CARTESIAN_POINT(“PT1”,(1.0,2.0,3.0)); ENTITY cartesian_point SUBTYPE OF (point); coordinates : LIST[1:3] OF length_measure; END_ENTITY; ENTITY representation_item; name : label; WHERE wr1 : SIZEOF(using_representations(SELF)) > 0; END_ENTITY;

PDES, Inc. Copyright PDES, Inc ® A Computer Interpretable Definition : Part 11 entity_decl=entity_head entity_body END_ENTITY ‘;’ ENTITY cartesian_point SUBTYPE OF (point); coordinates : LIST[1:3] OF length_measure; END_ENTITY; entity_head = ENTITY entity_id [subsuper] ‘;’ entity_body = {explicit_attr} [derive_clause] [inverse_clause] [unique_clause] [where_clause] [inverse_clause] [unique_clause] [where_clause]

PDES, Inc. Copyright PDES, Inc ® Do I need to know all this stuff ? No - If I only want to dabble Yes - If I want to understand what is going on

PDES, Inc. Copyright PDES, Inc ® Why STEP ? It addresses all product data - meta data as well as technical It is becoming a global standard It has 10+ years of development The e-world needs standards Modular architecture allows wide range of interoperability It has warts Development is at ISO-speed Industry requirements always moving ahead Pros and Cons but it works

PDES, Inc. Copyright PDES, Inc ® What does the market want ? Data Exchange Data Sharing Data Archiving Standards : STEP, OMG, XML Interoperability Involvement with standards development – PDES, Inc., OMG

PDES, Inc. Copyright PDES, Inc ® What do our customers really really want ? Conformance Full Implementation ? Robustness Consistent Implementation It has to satisfy my business need IT HAS TO WORK!

PDES, Inc. Copyright PDES, Inc ® Conformance Testing ? Eye halve a spelling chequer It came with my pea sea It plainly marques four my revue Miss steaks eye kin knot sea

PDES, Inc. Copyright PDES, Inc ® Conformance Testing ? Eye have run this poem threw it I am shore your pleased two no Its letter perfect awl the weigh Eye strike a key and type a word And weight four it two say Weather eye am wrong oar write It shows me strait a weigh. As soon as a mist ache is maid It nose bee fore two long And eye can put the error rite Its rare lea ever wrong. My chequer tolled me sew.

PDES, Inc. Copyright PDES, Inc ® Full Implementation ? ENTITY degenerate_pcurve SUBTYPE OF (point); basis_surface : surface; reference_to_curve : definitional_representation; WHERE WR1: SIZEOF(reference_to_curve\representation.items) = 1; WR2: 'CONFIG_CONTROL_DESIGN.CURVE' IN TYPEOF (reference_to_curve\representation.items[1]); WR3: reference_to_curve\representation.items[1]\ geometric_representation_item.dim = 2; END_ENTITY; -- degenerate_pcurve Nobody is expected to use this - so it has not been implemented so it has not been implemented

PDES, Inc. Copyright PDES, Inc ® IT HAS TO WORK! Compatibility with other translators Equivalent Implementation Sympathetic Implementation Implementors Agreements Testing Forums - CAx-IF, PDM-IF Pilot Projects - –PDES, Inc. Engineering Analysis Pilot (AP209) –Electro-Mechanical Pilot (AP210)

PDES, Inc. Copyright PDES, Inc ® Where do I start ? Understand the framework - Express, Part 21, Schema Understand the application - select an AP Read the recommended practices Select your tools –STEP Tools, Inc. ST-Developer –ProSTEP STEP ToolKit –homegrown ? Join PDES, Inc. –Access to training, expertise, consultancy Join an appropriate implementors forum –Check the implementors agreements

PDES, Inc. Copyright PDES, Inc ® How do I test my program ? Implementors Forum - access to library of test parts –but beware really old parts Syntax Checkers Conformance Checkers Other vendors translators

PDES, Inc. Copyright PDES, Inc ® How do I deliver it ? STEP translators cannot be considered as fully independent processors Functionality releases need to be coordinated Functionality needs to be backwards compatible Functionality needs to be ‘forwards’ compatible –Robustness to guard against change needs to be built in

PDES, Inc. Copyright PDES, Inc ® How do I maintain it ? STEP as a standard is here for the long haul As the standard evolves it needs to be supportive of REALLY old data Processors too need to be supportive of ANCIENT data

PDES, Inc. Copyright PDES, Inc ® Where is STEP going ? Modular STEP STEP ML SDAI STEP Based Repositories New Application Protocols New Disciplines etc

PDES, Inc. Copyright PDES, Inc ® Conclusions STEP Implementors have a hard time They need your sympathy (if you’re a user or developer) STEP processes provide a business benefit to users STEP on the web (e-STEP) will grow This is where data exchange ? Questions ?