Transcript EXPRESS and Binary Data

The ISO EXPRESS and
Binary Data Project
January 2005
Agenda
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Background
Survey of the state of the art
Requirements
Making the standard
Background : Need
• STEP and related standard information models are
written using the ISO EXPRESS language
• There are standard implementation methods for Text and
XML exchange of EXPRESS-driven data
– There are also low level standard Java, C and C++ programming
language interfaces for EXPRESS-driven data called SDAI
• Based on experience in the STEP for Space TAS/NRF,
Finite Element Analysis, Computational Fluid Dynamics
and other fields, requirements for a more efficient
exchange format have arisen
Background : VIVACE
• Value Improvement through a Virtual
Aeronautical Collaborative Enterprise
– VIVACE EU project started January 2004 for four
years
– EXPRESS-driven Large Volume Binary Data
Representation is defined as a VIVACE deliverable
• Mats Lindeblad is VIVACE task leader from Volvo Aero
• David Price is VIVACE technical resource from Eurostep
Limited
• Mats and David are proposed as the ISO SC4 Project Leader
and Editor
Background : STEP Meetings
• Mats set up initial discussions at ISO STEP in
Poitiers, France October 2003
• Team has met at each of the three ISO STEP
meetings in 2004
– Ft. Lauderdale : First announced meeting set out plan
for Survey of technologies and requirements
gathering
– Bath : Reviewed technologies and requirements,
created features analysis matrix
– Seattle : Decided on HDF5 technology for first
working draft and testing
Survey of State of the Art
• Searched for binary data representations to find
candidate technologies
• Search found
– ASN.1 : Abstract Syntax Notation 1
– HDF5 : Hierarchical Data Format
– XML/Binary
• Sun Fast Web Services
• WAP Binary XML
• Compact Binary XML
– CGNS : CFD General Notation System
– SDAI implementation by LKSoft
Gathered Requirements
• At each of the ISO STEP meetings,
requirements were gathered
– 40-50 requirements have been identified
• Based on requirements, a matrix of features was
derived
– Lists features needed by the proposed standard along
with a simple priority
• Measured HDF5 against those features and
reviewed results in October 2004 at Seattle ISO
STEP meeting
– Based on this and knowledge of other candidates,
those present decided HDF5 was the most suitable
HDF5 Technology
• HDF5 is more than simple compression,
contained data has structure
“/” (root)
“/foo”
3-D array
lat | lon | temp
----|-----|----12 | 23 | 3.1
15 | 24 | 4.2
17 | 21 | 3.6
palette
Table
Raster image
Raster image
2-D array
Making the Standard
• The first working draft will be based on HDF5 per
October 2004/Seattle decision
• Assume an ISO 10303-20s series part that is a “profile”
of HDF5 for use with EXPRESS
• Plan should be for an open-source toolkit built on top of
HDF5 that performs the EXPRESS/HDF5 mapping
– Enforce EXPRESS base types, EXPRESS->HDF5 structure
mapper, the mapper may need to be configured
– Should this be a Engineer Object Level API for STEP APs?
• A technical workshop is needed to create the working
draft
• A New Work Item ballot (NWI) or Preliminary Work Item
project (PWI) are required by the ISO SC4 STEP
procedures
PWI on “EXPRESS and Binary
Data”
• Evident industry need for complement to ISO10303-21/28
Usage Domains:
– Engineering Analysis, Manufacturing, Measurements and more
• Represent EXPRESS-compatible data in an efficient, binary form
• No standardized mapping from EXPRESS to binary exists
• Support from participants representing:
– Sweden, UK, US, Japan, Germany, France known
• Financing:
– Project Lead and Editor 2004-2007 from EU 6th FP project “VIVACE”
• Mats Lindeblad
• David Price
• Proposed PWI for project within SC4/WG11
– Proposed to target ISO 10303 Implementation Method
– Planned Project Milestones => Next slide
WG11: EXPRESS and Binary Data
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Presentation and Discussion on Business Need for Standard
Review and Update of Gathered Requirements
Review of Potential Implementation Technologies from Survey
– Defined and prioritised an initial set of features for comparison
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Planned Project Milestones:
– Jul 2004: PWI as SC4 Letter Ballot
– Sep 2004: Release analysis of potential candidate technologies
– Oct 2004 (Seattle SC4 meeting)
• Decide on scope & Candidate technologies to include in CD document
– Feb 2004 Release of first Working Draft for review and testing
– Mar 2005 (Lillehammer SC4 meeting)
• Hold walk through for ISO/SC4 community
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Jun 2005: Release of CD document for ballot
Jul 2005 (Spain SC4 meeting) walkthrough and implementation reports
Fall 2005 (SC4 meeting): Hold CD ballot resolution work shop
Early 2006: Publish ISO TS document
… to be planned …
Nov 2007 : Published ISO International Standard of document(s)
Workshop needs
• Produce a first working draft for implementors to do initial testing
• Choose a subset of EXPRESS for prototyping
– Not required for initial prototyping
• rules/functions
• abstract entity
• complex numbers
– Requirements
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Entity and Attribute
Defined types of arrays
Enum
Select (some include both Entity and DT of array),
all simple datatypes
3 level nested arrays of real
some redeclaration
Inverses
maybe derived and save results
lists are included
Workshop needs (2)
• Choose a subset of EXPRESS for prototyping (2)
– Structured grids? Part 50 more complex but would be in AP209
E2
– Configurability?
• For each Entity.attribute specify the encoding
• Simple datatype - specify the encoding at a global level
– Transactions at the level of a “engineering or business object”
level in the API
– AP209 testing
• Keith Hunten needs a higher level interface for application
programmers that is even higher level than the AP209 schema
• API is early bound to the schema, Keith would likely use C
Conclusion
• Sufficient industry interest and need exists
for the EXPRESS/Binary data
representation standard
• Good technology exists upon which to
build a standard without inventing
everything in ISO
• Anyone with similar needs/interests is
invited to participate in the standard or in
implementations