For Loop runs once when told to run more.

[mross]

Howdy all,

I am learning to work with TDMS. Maybe that is the source of the problem...

I have a for Loop that runs one pass and stops even though i have wire a 4 to the count terminal.

I do TDMS open, run some arrays to the border for indexing. In the loop I want to TDMS Write some numbers, several times, then loop and pick up the next index, write, and so on. Outside the loop is TDMS Close and I call the File Viewer.

I get no errors. I cannot get the loop to continue past the first iteration when it lets the output data go to the TDMS close and everything stops.

I may be messing up the TDMS write somehow - the way it works is a bit perplexing so I keep thinking I have it and then it doesn't like what I did. But like I said no errors.

I'd listen to advise. The wires are not pretty in the image as I have been tweaking, the open and close used to be outside the loop. Moving them inside changed nothing.

Thanks,

mike

[jgcode]

Hi Mross

What are the sizes of the array wired into the for loop? The smallest number determines the number of iterations. I am willing to bet one of them is equal to zero or one??

Cheers

-JG

[ShaunR]

The for loop will execute the number of times of the elements in the smallest indexing array regardless of what you wire to the N terminal. The N terminal is only of consequence if you have no array indexing or if the value you wire is less than the smallest indexing array.. I expect one of your data arrays is only 1 element in length.

This, for example, will only execute 3 times because the shortest indexing array is 3 elements long.

Edited February 21, 2011 by ShaunR

[mross]

The for loop will execute the number of times of the elements in the smallest indexing array regardless of what you wire to the N terminal. The N terminal is only of consequence if you have no array indexing or if the value you wire is less than the smallest indexing array.. I expect one of your data arrays is only 1 element in length.

This, for example, will only execute 3 times because the shortest indexing array is 3 elements long.

Shaun and JG,

I have been doing this for long enough you would think this little tidbit would have been noticed by me, but I have a habit of not auto-indexing when there are complications. This time I did it and noticed.

Thanks for the help,

Mike

[hooovahh]

This is a big Gotcha for LabVIEW programmers at least once in their career. There will be times when you have two arrays, and index them both going into a for loop and the intent is that both are the same size, but if for some odd reason they are not there will be problems like this.

[Ton Plomp]

This is a big Gotcha for LabVIEW programmers at least once in their career. There will be times when you have two arrays, and index them both going into a for loop and the intent is that both are the same size, but if for some odd reason they are not there will be problems like this.

Or how do I lose a reference:

(shift registers are your friend)

Ton

[jgcode]

Been there

[ShaunR]

Been there

....done that...bought the tee-shirt.....

[jgcode]

Ooh a t-shirt, I want one!!

[Ton Plomp]

Ooh a t-shirt, I want one!!

'My colleague fixed my dumb auto-indexing-for-loop-bug

And all I got was this t-shirt'