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Problem with Attributes in NX8 and the use of "format" in Expressions

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Hamburglar53

Mechanical
Mar 13, 2012
11
I stumbled across an issue with the way geometry Attributes work in NX8 that lead to the discovery of a more widespread problem that I could use some help with.

We use Attributes extensively to pass information from NX to ANSYS Workbench. Many of these Attributes point to Expressions. In NX7.5, when you reference an Expression with an Attribute it automatically gets converted to a String (using <X.4@Expression_Name>). This has worked fine in the past. When you first open an NX7.5 part in NX8, it converts all of these Attributes to the new NX8 Attributes. It does this by creating a new Expression with the formula: format("%.4f", Expression_Name). The newly converted Attribute is set to type String and points to the new Expression.

The problem is that the "format" function is also doing a behind-the-scenes unit conversion. If you create a Expression called RPM with the units of rev/min and a Number value of 10, the "format" function will automatically convert it to rev/sec and give you a String of "600". As a result, a lot of our attributes have one value in NX8 than the value they had in NX7.5 and the value of the Expressions they reference!

I've filed a ticket with GTAC, but I was wondering if anyone had any input on this.
 
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Can you provide an NX 7.5 sample file with just a couple of these Attribute/Expression sets defined?

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.
 
It appears to be an issue with the Expression, NOT the Attribute. A PR has been opened but I don't have a resolution status yet.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.
 
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