What is the purpose of the Index Array Function in attached example?

[Mikea01]

Hi,

I am struggling with the Index Array Function. I found the attached VI on the NI site which ws exactly what I wanted to do, but rather than just accept that it works and use it, I wanted to understand it.

What is the purpose of the Array Index Function inside the While loop? If I put a probe either side of it, the values are identical, yet if I remove the function and connect directly to the > function, I get errors.

I do understand arrays but I just don't get what is happening here. Any help would be gratefully appreciated.

Thanks in advance.

[pjr1121]

First, don't put lv2009 in the name of your vi if its saved in lv2012, that's just annoying.  Having said that, and since I can't open the vi, I can only hazard a guess based on its name.  

Index Array extracts an element from your array for evaluation/processing/whatever.  The array isn't changed in any way... Think of it like copy/paste.   

[jcarmody · Accepted solution]

It's just picking the first reading from the array in the waveform.  If this is good enough (I'd at least take the mean of the N Samples), why not this?

[Mikea01]

Hi,

that was the filename on the NI site. I've renamed it now. I've also attached an image of the block diagram so that the VI doesn't need to be opened. So any help on what the Index Array Function is doing would be great thanks.

[Mikea01]

Hi, thanks for your reply. We must have posted at the same time. I will look at your answer now thanks.

[Mikea01]

Hi Jim,

I've looked at your reply and most importantly I understand it. Thanks for finding the time to answer this for me.

Mike

[jcarmody]

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[...] Thanks for finding the time to answer this for me.

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You're welcome. You'll find no shortage of people here willing to help.