SubVi using while loops

[Streetgeezer]

I am new to Labview and probably have a simple question. I have created a subvi that requires the use of shift registers. The vi runs great until I drop it into a while loop. Is there a way to run a subvi using a while loop inside another while loop?

[Ray.R]

well....

The issue you might face is "how does the sub-vi come out of it's While Loop"...

Do you really need the 2 While Loops?

Can you describe what the code is doing?  What's the purpose of the sub-vi?  and better yet, can you post both main & sub-vi?

[altenbach]

Your question is way too vague. If the subVI does not complete, the calling VI will stall, of course.

If the subVI does not need a loop, you could replace the shift regsiter with a globablly initialized feedback node.

There are many other scenarios and possible solutions if you would tell us a little more on what your program is supposed to do.