A few extra ISO 14649 comments

Fri May 11 17:49:49 EDT 2001

Hi everybody,

At the Frankfurt meeting, we discussed an extra comment (#51 below)
that I had dicovered after the ballot closed, and I had promised to
send the rest of them around to the group.  

I discovered these while putting together the AIM, so they are mostly
just minor technical details of the EXPRESS (lists that should be
sets, the layout of some hierarchies, etc.) typographical errors and
descriptions that were just not as clear as they could be.

This list also contains another minor one (#66) I found while working
on the flight back from Frankfurt :-)

					   - Dave

----------------------------------------
ISSUE NUMBER: USA-14649-10 DIS #51
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.6.4.9.1 Complex Boolean expression
CLASSIFICATION: major, technical
DESCRIPTION: 

The current modeling of complex boolean expression is not clear
because it is not documented what the interplay between the operator
and the operands are.  The interpretation of the operand fields and 
which are required or must be unset depends on the operator.

PROPOSED SOLUTION: 

Eliminate the enums and remodel in a subtype fashion closer to the
PLIB Part 20 model.  The following hierarchy:

 ENTITY boolean_expression

 	ENTITY unary_boolean_expression 
		ENTITY not_expression,

 	ENTITY binary_boolean_expression
		ENTITY xor_expression
		ENTITY and_expression
		ENTITY or_expression

 	ENTITY comparison_expression
		ENTITY comparison_equal
		ENTITY comparison_not_equal
		ENTITY comparison_greater_equal
		ENTITY comparison_greater
		ENTITY comparison_less_equal
		ENTITY comparison_less

----------------------------------------
ISSUE NUMBER: USA-14649-10 DIS #52
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.3 Project
CLASSIFICATION: minor, technical
DESCRIPTION: 

How would this handle a program which works on multiple copies of the
same workpiece?  It's not clear how this would work on a fixture with
five or six copies of the same casting.  Since the project contains a
set of workpieces, it seems to imply that one would have to create a
bunch of copies of the workpiece data, which is not desirable. 

(NOTE - After I wrote this, I realized that this is actually done 
 using the setup, not the workpieces referenced through the product.
 So maybe the way to prevent this sort of confusion is to change the
 description of "its_workpieces" to say that these are the distinct
 set of things that are produced by the project)

Related to this question is how one would describe a program that
worked on a transfer line, or a machine with multiple spindles.  The
document does not say whether these are in or out of scope.

----------------------------------------
ISSUE NUMBER: USA-14649-10 DIS #53
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.4.2 Manufacturing feature
CLASSIFICATION: minor, technical
DESCRIPTION: 

The ordering of its_operations is declared to be important, but the
attribute is modeled using a set, which is unordered.

PROPOSED SOLUTION: 

change   its_operations: SET [0:?] OF machining_operation;
to       its_operations: LIST [0:?] OF machining_operation;

----------------------------------------
ISSUE NUMBER: USA-14649-10 DIS #54
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.5.1.2 Region surface list
CLASSIFICATION: minor, technical
DESCRIPTION: 

The surfaces are in a list, but unless the ordering has a specific
meaning, this should be modeled as a set instead.  This seems to be a
geometrically_bounded_surface_shape_representation as defined in the
STEP AIC 10303-507: aic_geometrically_bounded_surface.

PROPOSED SOLUTION: 

Change to the following - 

ENTITY region_surface_set
SUBTYPE OF (region);
surface_set : geometrically_bounded_surface_shape_representation
END_ENTITY;

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #55
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.5.12.2 Rectangular pattern
CLASSIFICATION: minor, technical
DESCRIPTION: 

The attribute names spacing and its_direction for rectangular pattern
are somewhat confusing.  They should be changed to column_spacing and
column_layout_direction to better match with the row_* counterparts
and the equivalent AP-224 definitions.

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #56
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.5.12.3 General pattern
CLASSIFICATION: minor, technical
DESCRIPTION: 

The replicate_locations attribute is a LIST, but there is no
additional semantic information from the ordering.  Change to be a SET
to better match the equivalent AP-224 definitions.

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #57
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.5.6 Step
CLASSIFICATION: minor, technical
DESCRIPTION: 

How is the floor_radius attribute different from the inherited
planar_radius attribute?  They appear to be the same thing.  If so,
the floor_radius should be removed.

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #58
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.6.2.3.4.1 Cutting tool
CLASSIFICATION: minor, technical
DESCRIPTION: 

The description seems to imply that the list of tool offset lengths
corresponds to the cutting edges, but the list of offset lengths must
have at least one value while the list of cutting edges can be empty.
What does this case mean?   

If the lengths are tied to the cutting component, then why not put the
lengths with the component, or use a relationship entity containing
the offset rather than using these parallel lists.

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #59
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.6.4.1.2 Setup
CLASSIFICATION: minor, technical
DESCRIPTION: 

The collection of workpiece positions is modeled as a list, but 
there is no additional information given by the ordering.  Model as
a set instead.  This also makes it easier to deal with in the aim.

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #60
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.8.6 Axis trajectory
CLASSIFICATION: minor, technical
DESCRIPTION: 

As with the modeling of 4.6.2.3.4.1 Cutting tool, you should create a
separate entity rather than keeping parallel lists.  Suggest that it be
modeled as a LIST [1:?] OF axis_command, where axis_command is defined 
as follows:

ENTITY axis_command;
   axis : identifier;
   movement_curve :  bounded_curve;
END_ENTITY;

14649-10 EDITORIAL COMMENTS ----------------------------------------
14649-10 EDITORIAL COMMENTS ----------------------------------------
14649-10 EDITORIAL COMMENTS ----------------------------------------

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #61
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.8.1 Toolpath
CLASSIFICATION: minor, editorial
DESCRIPTION: 

The description for its_priority is unclear.  Rewrite to state what
true and false each imply.  Does true mean the toolpath is required
while false means that it is only suggested?  Perhaps an enumeration
of required/suggested would be a clearer way to model this.

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #62
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.6.4.1.2 Setup
CLASSIFICATION: minor, editorial
DESCRIPTION: 

"By the setup's attribute ist_origin", mispelled its_origin

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #63
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.6.4.9.4 Binary operator
CLASSIFICATION: minor, editorial
DESCRIPTION: 

The logical_not enumerator mistakenly appears in both binary and 
unary enumerations.

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #64
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.5.10 Compound feature
CLASSIFICATION: minor, editorial
DESCRIPTION: 

What do the inherited planar/orthogonal radius and surface roughness
attributes mean for a compound feature?

----------------------------------------
ISSUE NUMBER: USA-14649-10  DIS #65
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.5.6 Step
CLASSIFICATION: minor, editorial
DESCRIPTION: 

"The step may have one *ore* more bosses ..."

Misspelled, change to "or".

----------------------------------------
I actually found this one on the flight back from Frankfurt

ISSUE NUMBER: USA-14649-10 and 11 #66
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.7.1.2 Tool direction
CLASSIFICATION: minor, editorial
DESCRIPTION: 

The EXPRESS definition is not syntactically correct.  There 
should be no equal sign.

	ENTITY tool_direction_select =

This error and the name imply that this definition was previously
modeled as a SELECT.  Since it is now the root of an entity hierarchy,
the name should be shortened to just "tool_direction" to avoid any
confusion.

14649-11 EDITORIAL COMMENTS ----------------------------------------
14649-11 EDITORIAL COMMENTS ----------------------------------------
14649-11 EDITORIAL COMMENTS ----------------------------------------
14649-11 EDITORIAL COMMENTS ----------------------------------------

----------------------------------------
ISSUE NUMBER: USA-14649-11 DIS #2
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 1 Scope
CLASSIFICATION: minor, editorial
DESCRIPTION: 
"it describe the interface between" should be "it *describes* the
interface between"

----------------------------------------
ISSUE NUMBER: USA-14649-11 DIS #3
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 2 Normative references
CLASSIFICATION: minor, editorial
DESCRIPTION:
Reference to the 10303 specs should be formatted as below:

ISO 10303-11:1994, Industrial automation systems - Product data
representation and exchange - Part 11: The EXPRESS language reference manual.

ISO 10303-21:1994, Industrial automation systems - Product data
representation and exchange - Part 21: Clear text encoding of exchange
structure.

----------------------------------------
ISSUE NUMBER: USA-14649-11 DIS #4
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 5.2.4 Milling technology
CLASSIFICATION: minor, editorial
DESCRIPTION: 
In description of synchronize_spindle_with_feed, "synchronised" should
be changed to "synchronized."

----------------------------------------
ISSUE NUMBER: USA-14649-11 DIS #5
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 4.6.2.3.4.1.2 Cutting component
CLASSIFICATION: minor, editorial
DESCRIPTION: 

The technology for a cutting component is defined as a milling
technology and talks about spindle speed and feed.  As defined, this
will not work for a non-milling tool.  The milling_technology should
be changed to the supertype technology so that it can be applied to
other types of machining.

	its_technology: OPTIONAL milling_technology;
should be
	its_technology: OPTIONAL technology;

14649-111 EDITORIAL COMMENTS ----------------------------------------
14649-111 EDITORIAL COMMENTS ----------------------------------------
14649-111 EDITORIAL COMMENTS ----------------------------------------
14649-111 EDITORIAL COMMENTS ----------------------------------------

----------------------------------------
ISSUE NUMBER: USA-14649-111 DIS #2
AUTHOR: Dave Loffredo (loffredo at steptools.com)
CLAUSE: 5.3.3 Centerdrill
CLASSIFICATION: minor, editorial
DESCRIPTION: 

The centerdrill entity is listed as a top level entity with no
supertypes, but I believe that it should be a subtype of tool body.
Most likely milling_tool_body or drill.

    ENTITY centerdrill;
    END_ENTITY;

In the Annex A express listing, it appears with a different spelling,
but the correct inheritance.

    ENTITY center_drill
    SUBTYPE OF (milling_tool_body);
    END_ENTITY;