Missing Data in Labview RT Acquire/Write to file Loop

[AbeG]

Hello all,

I am configuring a cDAQ-9137 for unmonitored continuous data acquisition and logging. I currently have my vi setup so that it acquires data from three channels and then writes the data to a .tdms file. The file changes every (global) hour. I've attached an image of my vi, my daq assistant setup, and my daq write to file setup.

My issue is that the third channel is usually 1000 samples short. When I switch the file rollover condition to minutes (so year/month/date/hour/minute) there are no missing samples. Any ideas?

[BrinkHombre]

Hello AbeG,

What operating system are you running on your cDAQ? Are you running any other processes on the computer that could be preventing the files from being read at the specified intervals? It looks like your writing 1,000 data points per second per channel. Thus after 1 hour you may have too many data points for Excel to read. When you create new files sooner, a more reasonable number of data points could be written to each file.

[Bob_Schor]

It is much easier for us to help you if you attach code that we can view in LabVIEW.  The easiest way to do this is to attach the VI itself, or if your project is within a LabVIEW Project, compress the folder containing the entire Project and attach the resulting .ZIP file.  You can also attach a LabVIEW Snippet (if you know what those are and how to make them), which at least gives us a picture we can "turn back into code" with LabVIEW.  Among other things, being able to open the code in LabVIEW would have enabled us to see for ourselves all of the Express VI settings, and would have allowed us to test your code and try modifications to see if we could "fix" it.

But why make it easy or convenient for us?

Bob Schor