NX7.5 files not compatible with NX6

[kevintsander]

Is there a way to save .prt files in NX7.5 to be compatible with NX6? We are currently making the switch, so a few users were working exclusively in NX7.5 and modified files only to find out they couldn't be opened by the rest of the users. It is kind of absurd that you can open a file created in NX7.5, save it without making any changes, and then it can no longer be opened in NX6.

 

[kevintsander]

Sorry, I meant to say "..open a file in NX7.5 that was created in NX6..."

 

[cowski]

faq561-1623

www.nxjournaling.com

 

[JohnRBaker]

No, there is NO way to make an NX part file saved in NX 7.5 able to be opened in NX 6.0 or any other version prior to NX 7.5.

If there is a need to move unparameterized solid/sheet bodies from a newer version of NX to an older version, the best approach is to go to...

File -> Export -> Parasolid...

...and select the target version from the list and select bodies that you wish to move. Once the file is create, open the older version of NX and go to...

File -> Open...

...and change the 'Files of type:' at the bottom of the dialog to the Parasolid format used when you created your exported file from NX 7.5, browse to where you saved that file, select it and hit OK. Now you will at least have an older NX part file with an accurate and faithful, but nonparametric copy of the selected Solid/Sheet models from the newer version of NX.



John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

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

 

[cowski]

It is kind of absurd that you can open a file created in NX7.5, save it without making any changes, and then it can no longer be opened in NX6.

When you open a prt file in a newer version of NX, some updates to the new file structure happen 'behind the scenes'. Even if you didn't make any changes, the system did. That is why when you open an older file it is immediately marked as modified.

www.nxjournaling.com

 

[kevintsander]

Thanks guys,

I definitely can understand why the standard file format is not compatible, I just find it odd that there's no way to save the file in a format that is compatible with an older version (without having to go through a lengthy export process.) Many other programs have been doing this for years.

 

[JohnRBaker]

If you're referring to "programs" like Word or Excel, PLEASE...

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

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

 

[kevintsander]

I'm aware that CAD modeling programs are significantly more complicated in their architecture than Word and Excel. But if I save a file in NX7.5 that was originally created in NX6 without using any geometry that was not possible to do in NX6, I really don't think it is a crazy thought to allow for some compatibility between the two. But hey, it's not the end of the world. We'll all be switched over in a week

 

[JohnRBaker]

At least with NX, the way older part files are 'updated' on the fly (i.e. 'as they are opened') is based on an architectural approach using what we call a 'schema-file'. Each new version of NX has defined a 'schema-file' which carries with it all of the information needed to apply databases changes made in the current release of NX to the most recent generation of NX Part file. In other words, as NX opens a Part file it checks to see what the last version that this file was last saved in and based on that information the software applies, in order, all the relevant 'schemas' one-by-one until the part file is now fully compatible with the version of NX which was used to open the part file. Those changes have already been applied automatically so that you could start to immediately either edit the file or add new objects using any existing object as reference without ever having to be concerned whether the data was valid or not. And before you ask, why doesn't the software wait until you actual do something before applying this 'auto-update', there are a couple of issues, the most minor being that it was felt that since these updates do take additional time, that they be performed during the file opening operation itself since this would reduce the likelihood that the user would notice this whereas if we waited and performed the update AFTER he had actually selected an operation, but before it was executed, it would definitely be noticed and could even appear to be a problem if the time lag was significant, which will vary with both how many versions back the part was being updated from and the amount and type of data in the part file.

However, the biggest issue is that if you were opening an Assembly containing part models from older versions of NX, if we did NOT perform the update immediately on ALL legacy parts being opened in the session, there could be significant issues with respect to any relationships between them and other parts in the Assembly which were already up-to-date and which were therefore expecting to see valid data formatted based on the current database specifications.

Perhaps an extreme, but not unaccounted for nor even unheard of, example may help.

I have on my system (and we have many other files like this which are used in testing) that was last saved in Unigraphics V9.1 (released in December 1992, nearly 20 years ago). This file represents the oldest version of a UG/NX part file which we 'guarantee' can be opened by the CURRENT version of NX. So when I test this workflow by opening this particular file using the latest version of NX, in this case NX 8.5 that is currently in beta testing and which will be released this Fall, 37 back-to-back schema updates are performed as the file is being opened and loaded into the current session. If we had waited until the user had actually decided to perform an operation before performing this litany of updates I'm not sure that there would have been anything even displayed on the screen let along something which I could select before I performed that first operation, whatever it might be.

Now before we finish this discussion please understand that while we work very hard to keep this automatic 'version-up' task usable as an on-the-fly type operation, we recommend that you upgrade your part file archives using the batch 'refile' utility supplied with each new release of NX since this is much more convenient and less time consuming in the end.

BTW, for the record, I'll put NX's ability to open and work with legacy files up against any software in the industry, including Word or Excel when it comes to how many versions back one can go and still have full access to the data in legacy files and have that be in a state where it's still usable and viable with respect to today's applications and functionality.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

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

 

[kevintsander]

I really do appreciate the thoughtful response, John. It is very interesting to know how it works. I'm sorry if I was insulting in the manner I posted, that was certainly not my intent.

 

[miked64]

I have used many cad/cam softwares over the years, i dont know of any of them that allow you
to work in a newer version or release of there softwares and save to an older one? What
cad or cam softwares do this?

 

[petulf]

Actually Catia V6 has this functionality, it is able to "export" parts back to V5

"3D Models created in CATIA Version 6 can now be sent to V5, retaining their core features. These features can be accessed and modified directly in V5. A design can now evolve iteratively, with engineers having the freedom to create and modify the part at the feature level, whether they use CATIA V5 or Version6. All features in Part Design, Generative Surface Design and Sketcher, related to 3D parametric geometry creation are preserved, as are assembly structures and positional matrices."

 

[miked64]

used many but not catia, good info, thanks

 

[SDETERS]

In Autocad You can save Back to at least release Version "12" I think they are on Autocad 2012. Please do not confuse the two twelve’s. The Version 12 was released in 1996 or so.

 

[FrankMalone]

Perhaps catia V6 can save in Catia V5 but, what about v4 and v5?. The issue is amazing, v5 cant write in v4 and worse, v5 can't read v4 without a migration. Catia is not a good example of compatibility.

Regards
Frank.

 

[Toost]

And finally, there must be a very-very good reason to take the decision on spending the development time and money on developing a backwards saving compability. ( As all development organisations NX development probably has a budget...)
In the Catia case, - they did have that reason due to that when they released V5 initially it was far from a complete system, some jobs had to be finished in V4, -using a translator.
Regards,
Tomas