Sound to be heard only time , but program should continue running

[aashley]

Hello Everyone , 

I have made a small project in which I have used 'Text to speak' ,when ever I implement this program it continuously speaks either 'FULL' or 'LITTLE' respective of which I have mentioned in my vi , attached below.

My only query is that I want it to speak only once either 'FULL' or 'LITTLE' according to the condition but the program should continue to work.

I went through multiple forum responses but was confused alot therefore to have a clear answer , I approached here.

In short: program runs --> if slider greater than 5 --> speak 'FULL' but only one time ---> if slider goes less than 5 ---> speak 'LITTLE' but only one time.

Please guide which component can help for this problem.

Thanking in Advance.

[Andrey_Dmitriev]

Most simple modification  is something like that:

[Bob_Schor]

What you are looking for is a "Rising Edge Detector" and a "Falling Edge Detector" (to tell you when your slider value goes "above" or "below" 5.  Here it helps to have taken a course in Symbolic Logic and know about the operation "implies", a very useful (and, I'll bet, never used by at least 95% of all LabVIEW developers).  I won't give you the little lecture, but suffice to say P => Q ("P implies Q") is true in all cases except P is True and Q is False.  What is even more interesting is the negation of P => Q, which is True only when Q is True and P is False.

"OK, Bob, but how does that help us?  What are P and Q?"

P is "The last value of the slider is > 5" and Q is "The current value of the slider is > 5".  Do you see what that implies?  The slider has just crossed 5, otherwise known as a "Rising Edge Detector".  So how do you make a Falling Edge Detector?  Put the negation of "The current value of the slider is > 5" through a Rising Edge Detector!

So here is a Snippet based on what I just said:

But when I was saving this Snippet, I found another Snippet with almost the same name, but monstrously simpler (and using some interesting "Boolean functions"):

Have fun with these.

Bob Schor

[Andrey_Dmitriev]

---

@Bob_Schor wrote:

What you are looking for is a "Rising Edge Detector" and a "Falling Edge Detector" ...

---

Well, using SubVI this can be stripped down to the following:

But the author is definitivily beginner, I guess, so may be better to follow "straight forward" solution first without "magic" for educational purposes, even if it not so elegant.

[aashley]

Thankyou everyone for helping for this query. I have checked and tried everyone's vi and all of them works as desired.