Labview Basics

[Benomair]

Hello. 

I'm new to labview.. I'm trying to reset the first call based on the this: 

http://forums.ni.com/ni/board/crawl_message?board.id=7124&message.id=991

 

please..  I'd like to ask what the simple that connected to the loop condition ?? , 

many thanks in advance 

[RavensFan]

That is a boolean constant.  (Newer versions of LabVIEW simplifed that to just show the True, or the False, not the fact that you can swap between them.)  In this case it is set for False.  It is also much more common nowadays for 1 run loops to have a True wired to a Stop condition terminal rather than a False wired to a Continue terminal.

[Yamaeda]

That's a False constant.

/Y

[Benomair]

Thank you so much ..

I treid to change it to false constant but it would do the job.. since it still first_time (the output is on even after first loop)

regards 

[GerdW]

What's the purpose of the loop at all?

(the output is on even after first loop)

Did you debug your VI? What's the input value?

[Yamaeda]

---

@GerdW wrote:

What's the purpose of the loop at all?

---

The first time you read it after a Reset you want FirstTime to be true. 🙂

/Y

[Benomair]

Hi.. 

It is to be used to initialize the initial conditions for sub vi .. only for first call 

regards 

[GerdW]

Hi Benomair,

used to initialize the initial conditions for sub vi .. only for first call

So when you want to initialize ONLY for first call you don't need all those additional stuff.

When you want to initialize based on a different condition you don't need the FirstCall? primitive…

[Benomair]

Hi GerdW
thanks ..
sorry it might be too simple (I'm new to Labview) .. but I don't know how to initialize the initial condition for sub vi that using formula node ..
in Matlab I used this code to do so

persistent X_hat;
if isempty(X_hat)
X_hat=[0.018 0 0.894]';
end

regards

[crossrulz]

Perhaps you should show up your subVI and its caller so we have a better idea of what you are trying to accomplish.  We can offer better help then.