Why some people say Local Variables are bad...

[Ray.R]

There's more code.  It's all Locals.  I only posted one Event Case.

The Stop Scan won't be doing much either since it's outside both loops.

Message Edited by JoeLabView on 07-07-2008 10:13 AM

[tbob]

If the Stop Scan button is pressed while the innermost loop is running, it will stop the loop.  However, the outer loop has already seen Stop Scan as not being pressed, so it will kick off another inner loop.  This will execute one more time than probably what was intended.  I'm assuming that the mechanical action is not a latch because of the local variables.  If it were a latch, it would be reset as soon as the inner loop reads it and the program would never stop.

[Ray.R]

Very well explained tbob..  🙂

Not speaking from experience..  Of course... such a thing has never happened to us (even a long time ago), right?

cough... cough...

😉

[Ray.R]

Not an abuse...  and not a Local..

But Shift Registers would be more appropriate than using Global Variables

[Ben]

Actually its more serious that that. There is no guarentte that the lock-press will be set before the seq frame. Even if LV compiles the code such that it does set that flag before the seq today, a re-compile could result in LV changing the order such that the flag does not get set.

Judging by the names used, that could be a serious safety issue.

In which thread did you find that image? I feel obligated to warn them.

Ben

[Ray.R]

Oops... I should have posted that.  Lemme look for it.

(see it is good that we have this thread) 😉

[Ray.R]

It is from : http://forums.ni.com/ni/board/message?board.id=170&thread.id=339223

[Ben]

Thank you Ray,

It looks like Gerd is already on it.

Ben

[Ray.R]

yes... and the code underwent further improvements.

[Ray.R]

Slight abuse where wires would do the trick

From: http://forums.ni.com/ni/board/message?board.id=170&thread.id=340282

Improved by smercurio:

Message Edited by JoeLabView on 07-12-2008 10:54 AM