Minutes of 5th AP-238 CC1 testing telcon

st-announce at steptools.com st-announce at steptools.com
Mon Dec 20 14:30:17 EST 2004


Minutes of the AP-238 CC1 Testing Telcon on December 16th

The following systems will be used to create and save AP-238
CC1 files for testing by the controllers at the OMAC
demonstration.

Pratt and Whitney			UGS UNX
General Dynamics Land Systems		GibbsCAM
National Institute of Standards	Mastercam
Boeing					CATIA and UGS UNX
Caterpillar				APT and/or UGS UNX

The following two issues were raised by during the call and by
e-mail.

1. Data Portability vs Process Portability

It is important to distinguish between data portability and process
portability because the process in an AP-238 CC1 file may not be
compatible with the CNC machine that is reading the data. AP-238 CC1
makes it possible for a CNC program to be read into any machine tool
but the user must be careful to make sure that the processes 
(e.g. speeds and feeds) in the file are compatible with the
machine.

If they are not compatible then the process must be adjusted by
reading the data back into a CAM system and adjusting the parameters
until they are compatible. This is why it is so important for AP-238
to be a bi-directional standard (CAM and CNC can both read and write
the data).


2. Testing using EXPRESS Conformance Checking Tools.

It is important for others to be able to independently verify that
the data produced by the systems conforms to the standard. This
means checking it using independently developed software such as
the EXPRESSO conformance checker developed by NIST.

The AP-238 Walkthru slides on the web site describe how to construct
an AP-238 CC1 file that will machine the part, but they do not include
include all of the extra data required by a STEP standard and
checked by EXPRESSO and APCONFORM (a similar tool developed by STEP
Tools).

Therefore, implementation of the translators will be done in two
stages. A second set of slides will be added to the web site before
the next conference call describing what entities need to be added to
the data to achieve full conformance to the standard. 

To keep the barrier to entry low we will allow two kinds of files to
be used at the demonstration

1. Level 1: files that can be used to machine the part.
2. Level 2: files that can be used to machine the part and conform
   to all the rules described by the EXPRESS model of the standard.

A CAM vendor can decide whether to deliver Level 1 or Level 2 files
for the demonstration. A Level 1 file will be run on the controls but
it will not be EXPRESS checked because of the large number of
messages that conformance checkers typically produce when an error
applies to many entities in a file (such as every Cartesian Point).

Those vendors that wish to conform by implementing Level 2 will be
able to do so after a set of update slides with all the necessary
changes have been added to the web site. (See action items). The
updates will be implemented between the first round and second 
rounds of testing (see project plan).

Action Items:
* GDLS, Caterpillar, Boeing, Pratt and Whitney and NIST to prepare 
  machining plans for the NAS 979 CDS Cone part in their chosen CAM
  systems.
* GibbsCAM, CNC Software (Mastercam), UGS and STEP Tools to prepare
  Level 1 AP-238 CC1 export translators.
* Martin Hardwick to prepare a new set of slides with the additions
  required for Level 2 files.

Meeting Attendees:
Fred Proctor and Xun Xu. NIST
David Longenbach, Caterpillar
Mauro Costas, Boeing Seattle
David Odendahl Boeing Tulsa
Carol Tierney, GDLS
Chen Han Lee, UGS

Apologies for absence:
Ming Lui and Waris Jeffrey, Boeing Wichita
John Callen, GibbsCAM
Sid Venkatesh, Boeing Seattle

We apologize for the inconveniences cause by the bad pass code.
The next telcon will be held on Friday January 7th at 2PM Eastern.

As recorded by Martin Hardwick on December 16, 2004.
Merry Christmas and a Happy New Year to all.




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