Drive expression from PMI in NX7.5

[ChrisAbbott]

Hello,

Does anyone know if it is possible to have the "value" of a PMI annotation text (such as a Note or Balloon) drive the value of an expression?

To provide some context, we have a complex expression formula that drives the size of some geometry based on a value of 1, 2 or 3 (referring to specifications, so for example, typing in a value of 1 for an expression makes the geometry 300x100, or a value of 2 makes it 325x100...)

It would be handy to have a callout we can double-click and edit rather than delving into the expressions. Something like a balloon where we can edit the value would be perfect, but obviously this is derived as text rather than a parameter. Anyone have any thoughts?

Thanks.

 

[JohnRBaker]

Text objects, be they PMI or Drafting notes, can represent the value of an expression or attribute, but the no the other way round, that is, they are 'read only'. If you're not comfortable with editing expressions, have to looked into doing this with an attribute instead? In fact, if you're running NX 8.0 or later version of NX, you can create an attribute which can be limited to say the values of 1,2 or 3 so that it's very easy to make a change and assure yourself that it will be limited only ONE of those 3 values, which can then be passed to the expression system so as to control the value of one or more expressions, that values of which, along with the attribute, could then be displayed as text in your model or on a Drawing. But even with NX 7.5 you could still drive expressions from attributes, just that the interface is a bit mode complicated getting set-up and of course you would have to be disciplined in making sure that you only entered a 1, 2 or 3.

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.

 

[ChrisAbbott]

Thanks for the reply.

We're fine with expressions and attributes, but this will have to be used by the general CAD-consuming population of the business...who I have less faith in not to get it wrong.

It just seemed like a handy idea - to have a callout that could control one or a number of expressions via a double-click.

Probably going to reevaluate the process, and use part families instead perhaps.

 

[JohnRBaker]

Of course, this was one of the reasons for the NX 8.0 attribute project, to provide an alternative interface which could be better controlled and/or adapted for casual users. For example, with reference to your situation, starting with NX 8.0, you could define an attribute which has ONLY three valid values, 1, 2 or 3, and when accessed, the user MUST select from ONE of these three integer values and NOTHING else. There are also options to define a 'range' where any value between two limits can be entered. Also simple Boolean attributes where only a 'True' or 'False' option is valid for binary situations. Granted, it's not as simple as selecting something on a model or the face of a Drawing, but it's a lot easier to use than messing directly with the value of an expression.

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.

 

[PSI-CAD]

Hi Chris,

Do you know that User Defined Expressions appeared in a special folder from the Part Navigator ? (have a look at the jpeg file)

So it's easier and faster than opening Expression Menu.

I hope this help if you don't already know this function


Regards
Didier Psaltopoulos

http://www.psi-cad.com

 

[ChrisAbbott]

Thank you for the replies.

Unfortunately, John, we're stuck at 7.5! For the time being we will have to look elsewhere, but this is definitely a good method of finite control going forward.

Didier, this is also something we looked at. The more we thought about it, though, the more we thought about the requirement for specific values only. That makes it easy to see, but doesn't stop someone getting it wrong!