Data set doesn't appear in CSV file

[flying_fish]

Hello all,

I am new to LabVIEW so bear with me for a second...I have a VI that was mostly the work of someone who I am no longer in contact with.  I put in a small modification which was a filter, and also a write-to-file thing that would give me the data after it has been filtered, but before any other processing.

For a while I was using a low pass filter, which worked fine in terms of my data set being written to a csv file.  However, I am currently interested in using a smoothing algorithm rather than a low pass filter.  When I change the filter to a smoothing algorithm, it still creates a file, but when I open the file there is no data in it (just an empty CSV file).  Additionally, if I completely bypass the filter, I also get no data in the file created.

Does anyone have any insight into why it doesn't work with a smoothing algorithm, or absent filter, but does with a low pass filter?

I have included a picture with a red line to show the flow of data that I am interested in.  The big red circle shows the filter that i am talking about.  The input data is from a TDMS file and the output is a CSV file. 

Thanks for any and all insight!

Chris

[RavensFan]

It is hard to debug a partial screenshot of code.  If you attached the actual VI, we might have a chance.

Why do you have open file functions in there not connected to anything?

You also don't have a True constant wired up so that the Write to Spreadsheet file can append new data to the file.  Perhaps you are overwriting your data.

[johnsold]

Chris,

All the details of what the filter is doing are hidden. They only appear on the configuration dialog or in the code inside the Express VI. Without the actual code (an image is useless) we cannot tell.

Most likely the filter is configured in such a way that the output is empty so that there is nothing to write to the file.

Try putting some indicators at the input and output of the filter to see what is there.

Lynn

[flying_fish]

Thanks for the input.  It looks like I finally figured it out; the write-to-file vi was not configured correctly.  I still have no clue what I'm doing, but I got it to work by copying and pasting from elsewhere in the VI.  I'll work on giving myself a crash course in LabVIEW so I can ask more intelligent questions next time. 

Thanks!

Chris

[johnsold]

Chris,

If you have not had any formal training in LV, spend a few hours on the on-line tutorials.  They will answer a lot of your questions and save you far more time than the tutorials require in the long run.

Lynn