STEP Tutorial:“How a Software Developer

Implements STEP”

Tony Ranger, Theorem SolutionsJanuary 16, 2001

®PDES, Inc.

PDES, Inc. Copyright PDES, Inc. 2001®

Who am I ?

A “developer” develops the standardAn “implementor” implements the developed standardA “user” uses the implemented standard

I am an implementor (I know my place!)

PDES, Inc. Copyright PDES, Inc. 2001®

What is STEP ?

A Neutral Format for Product DataAn International Standard - ISO 10303A 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. 2001®

A Neutral Format

#1723=CARTESIAN_POINT(“PT1”,(1.0,2.0,3.0));#1723=CARTESIAN_POINT(“PT1”,(1.0,2.0,3.0));

PDES, Inc. Copyright PDES, Inc. 2001®

A Computer Interpretable Definition : Part 21

#1723=CARTESIAN_POINT(“PT1”,(1.0,2.0,3.0));#1723=CARTESIAN_POINT(“PT1”,(1.0,2.0,3.0));

ENTITY_INSTANCE = ENTITY_INSTC_NAME “=“ ENTITY_INSTANCE = ENTITY_INSTC_NAME “=“

SIMPLE_RECORD “;”SIMPLE_RECORD “;”

ENTITY_INSTC_NAME = “#” DIGIT [DIGIT [DIGIT [DIGITENTITY_INSTC_NAME = “#” DIGIT [DIGIT [DIGIT [DIGIT

[DIGIT [DIGIT [DIGIT [DIGIT [DIGIT [DIGIT ]]]]]]] .[DIGIT [DIGIT [DIGIT [DIGIT [DIGIT [DIGIT ]]]]]]] .

SIMPLE_RECORD = KEYWORD “(“ [ PARAMETER_LIST ] SIMPLE_RECORD = KEYWORD “(“ [ PARAMETER_LIST ] “)” “)”

PDES, Inc. Copyright PDES, Inc. 2001®

A Computer Interpretable Definition : Express

#1723=CARTESIAN_POINT(“PT1”,(1.0,2.0,3.0));#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;

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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. 2001®

A Computer Interpretable Definition : Express (3)

#1723=CARTESIAN_POINT(“PT1”,(1.0,2.0,3.0));#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. 2001®

A Computer Interpretable Definition : Part 11

entity_decl=entity_head entity_body END_ENTITY ‘;’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_head = ENTITY entity_id [subsuper] ‘;’

entity_body = {explicit_attr} [derive_clause] entity_body = {explicit_attr} [derive_clause]

[inverse_clause] [unique_clause] [where_clause] [inverse_clause] [unique_clause] [where_clause]

PDES, Inc. Copyright PDES, Inc. 2001®

Do I need to know all this stuff ?

No - If I only want to dabbleYes - If I want to understand what is going on

PDES, Inc. Copyright PDES, Inc. 2001®

Why STEP ?

It addresses all product data - meta data as well as technical It is becoming a global standard It has 10+ years of developmentThe e-world needs standardsModular architecture allows wide range of interoperability

It has wartsDevelopment is at ISO-speed Industry requirements always moving ahead

Pros and ConsPros and Cons

but it worksbut it works

PDES, Inc. Copyright PDES, Inc. 2001®

What does the market want ?

Data ExchangeData SharingData ArchivingStandards : STEP, OMG, XML Interoperability Involvement with standards development

– PDES, Inc., OMG

PDES, Inc. Copyright PDES, Inc. 2001®

What do our customers really really want ?

ConformanceFull Implementation ?RobustnessConsistent Implementation

It has to satisfy my business need IT HAS TO WORK!

PDES, Inc. Copyright PDES, Inc. 2001®

Conformance Testing ?

Eye halve a spelling chequerIt came with my pea seaIt plainly marques four my revueMiss steaks eye kin knot sea

PDES, Inc. Copyright PDES, Inc. 2001®

Conformance Testing ?

Eye have run this poem threw itI am shore your pleased two noIts letter perfect awl the weigh

Eye strike a key and type a wordAnd weight four it two sayWeather eye am wrong oar writeIt shows me strait a weigh.As soon as a mist ache is maidIt nose bee fore two longAnd eye can put the error riteIts rare lea ever wrong.

My chequer tolled me sew.

PDES, Inc. Copyright PDES, Inc. 2001®

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 -Nobody is expected to use this -

so it has not been implementedso it has not been implemented

PDES, Inc. Copyright PDES, Inc. 2001®

IT HAS TO WORK!Compatibility with other translatorsEquivalent ImplementationSympathetic Implementation Implementors Agreements

Testing Forums - CAx-IF, PDM-IFPilot Projects -

– PDES, Inc. Engineering Analysis Pilot (AP209)– Electro-Mechanical Pilot (AP210)

PDES, Inc. Copyright PDES, Inc. 2001®

Where do I start ?

Understand the framework - Express, Part 21, Schema Understand the application - select an APRead 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. 2001®

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. 2001®

How do I deliver it ?

STEP translators cannot be considered as fully independent processors

Functionality releases need to be coordinatedFunctionality needs to be backwards compatibleFunctionality needs to be ‘forwards’ compatible

– Robustness to guard against change needs to be built in

PDES, Inc. Copyright PDES, Inc. 2001®

How do I maintain it ?

STEP as a standard is here for the long haulAs the standard evolves it needs to be supportive of

REALLY old dataProcessors too need to be supportive of ANCIENT data

PDES, Inc. Copyright PDES, Inc. 2001®

Where is STEP going ?

Modular STEPSTEP MLSDAISTEP Based Repositories New Application ProtocolsNew Disciplinesetc

PDES, Inc. Copyright PDES, Inc. 2001®

Conclusions

STEP Implementors have a hard timeThey need your sympathy (if you’re a user or developer)STEP processes provide a business benefit to usersSTEP on the web (e-STEP) will grow

This is where data exchange is @

? Questions ?