NX expressions 2

[tadej001]

Hello everyone,

Does anybody know, where to find some detailed explanation on how expressions works in NX? By that I mean...how exactly define an if, else or some other statement to define relations between expressions?

Thanks in advance....
Regards,
Tadej

 

[jerry1423]

Do a search in this forum, or go onto the HELP that NX provides, to find more info.

The value of every parameter of every features is located in the expressions. You can do just almost anything with them related to math. The math involved is very similar to that of a spreadsheet.

 

[JohnRBaker]

May I suggest that you open the User Documentation and go to...

Design -> Modeling -> Modeling Tools -> Expressions

...and once you are there, select any one of the topics. Once the page is displayed, selecting either of the links at the top of the page titled...

'How To' 'Options' 'Related Topics'

...which will give you some additional links to other documents which will help you learn what you can do with Expressions.

Note that starting in NX 6, you only need to select the 'Related Topics' option from any of the Expression help pages and you will get a single consolidated list of links to ALL of the various sections of the documentation covering Expression issues, however prior to NX 6, you should try all of the above titled items since the various links are distributed across all 3 of them.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

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

 

[hudson888]

Tadej,

Even opening the expressions under modelling Tools>Expressions then hit the F1 key for help gives you a useful and easy to find reference to the documentation contents. It tells you about the editor but provides a click-able link to an Overview which describes some basic stuff about expressions.

Because your question is really broad it is difficult to be specific, but the parameters you specify in features and sketches as you model are automatically assigned expressions p1, p2 , p3... which can be edited using the expressions editor to change these values. The expressions editor also supports logical and arithmetical functions (math and trigonometry) to create values that can be used as parameters in you models.

Lastly you can display expression values on the face of a drawing if you so desire using Annotation relationships.

Have a think about what it is that you want and need to do then post a specific question when you first get stuck!

Best Regards

Hudson

www.jamb.com.au

Nil Desperandum illegitimi non carborundum

 

[JohnRBaker]

You may also wish to check out some of the material and examples which can be found in this thread:

http://www.eng-tips.com/viewthread.cfm?qid=232209&page=1

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

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

 

[crazydiamond]

I have a question regarding expressions using NX6. In the ‘checks’ column I created a ‘requirement’. How can I edit or delete the check requirement I created?

Thanks in advance for any help.

Ron
Design Analyst

 

[JohnRBaker]

To access an existing requirement for editing/deleting, go to...

Analysis -> Check Requirements...

...where you can select any of the current Requirements and either edit them, break there link to an expressions, or delete the Requirement altogether.

Note that the reason this is done this way and not from inside the expression system is two fold. For one, contrary to what it might look like, an Expression doesn't actually OWN the requirement, but rather the other way around. Granted, you can create a Requirement from the Expression system but in reality what is happening is that we are simply using the Expression system as a way of getting to the Requirement CREATION/ASSIGNMENT mechanism, but not access to the editing or deletion options. Note that we did this to streamline the process of creating a new Requirement rather than forcing a user to go to a separate 'Define a Requirement' sort of function before he can assign it to an Expression (which he can do if he wished by going to the 'Check Requirements' dialog first), but what's really happening is that a Requirement is being created and THEN the assignment of an Expression is being made, IN THAT ORDER.

What you've already noticed of course is that once created, a user can NOT edit or delete a Requirement from within the Expression system and that is BY DESIGN. What this does is allow a company to remove the 'Check Requirements' menu item from the Analysis pull down menu which would create an environment where existing Requirements in a model can NOT be altered or removed by someone who perhaps is not 'authorized' to define Requirements but who is still expected to abide by and honor the Requirements which are already in a part design.

Anyway, I hope that helps as well as make it a little clearer as to why we arranged the different aspects of managing Requirements in the way in which we did.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

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

 

[crazydiamond]

Thanks John, that's exactly the information I needed.

Ron
Design Analyst

 

[tadej001]

Thanks John,

I was looking for somthing similar...I was designing some parametric model...and insted of only check requirements I needed the expressions to prevent other users to do "stupid things".

I looked into NX documentation, but there are only few things describet how things works. I found more detailed help at UGS GTAC support.

Ok...thanks again!

Regards,
Tadej