Dimensional Measuring Interface
Standard
Standard Improvement Request
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SIR No. 97-40 DMIS Release 3.0 SIR Type Enhancement Severity Other Status Resolved Date Submitted July 22 1997 Date Validated July 22 1997 Date In Process Date Referred Date Vote Pending Date Closed April 1 1998 Action Clarifications Submitted By Dietmar May Object Workshops, Inc. PO Box 597 Whytheville VA 24382 USA Phone: (540)223-1145 Fax: (540)223-1241 dcmay@object-workshops.com |
Problem Topic
F(): Feature Nominal info per diff CS
Problem Description
Previously resolved SIR #97-26 clarifies that "feature nominal coordinates retain their original values during any subsequent coordinate
system transformations, with nominal values unchanged throughout the execution
of the system." This means that, if there is a change in coordinate system
after a feature has been measured, there is no way to to reference the true
location of the feature relative to the new coordinate system.
What is needed is a way to access the feature nominal information both as presently described, and optionally, as coordinates relative to the current coordinate system.
References
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Related SIRs
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Suggested Resolution
Create a new feature label type, perhaps FN(label), at the same time that the
feature actual FA(label) is created (ie, during feature calculation). When the
FN(label) created, the current part coordinate system would be associated with
the nominal feature. Then, during subsequent uses of the FN(label) feature, its
coordinate would be transformed into the coordinate system that is current at
the time of use. This means that FN(label) would provide access to the feature
nominal information in the current coordinate system, while F(label) would
operate as it always has. OUTPUT/, OBTAIN/, parameters to CONST/, and other
statements which support feature nominals would need to be updated to allow
FN(label).
This way, OUTPUT/F(label) would output the untransformed original coordinates with which the feature nominal was defined, OUTPUT/FN(label) would output the transformed coordinates relative to the active coordinate system at the time of OUTPUT/.
(Note: FN(label) is suggested instead of FC(label), which would conflict with E-DUG extensions).
Support Documentation
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Resolution
Warning!!
The following statement is only a resolution to a Standard Improvement Request (SIR) and is NOT part of the current DMIS standard, nor is it guaranteed to become part of the next revision of the DMIS standard even if voted and accepted by the DMIS National Standards Committee. This resolution is tentative because it may not be incorporated into the next version of the standard, it could be changed prior to the next release, or it could be changed as the result of the "public review and comment" period required for the next version of the standard. If you choose to use this tentative resolution, you do so at your own risk since at this time it is not part of the DMIS standard.
Attachments
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Notes
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