What is causing crash when using Write to Measurement file VI?

[mpatterson]

I am using the express VI, Write to Measurement on a PXI8106.  When I run the application without writing to a TDMS file, the application will run for days. If I write TDMS files, the application periodically crashes every few hours. I have read that with the PXI's fat32 file system that the file sizes should be limited to multiples of 4096 bytes. I have also heard that writing to the root directory of the PXI, will cause problems- files should be written to a sub-directory. I have also verified that disk space is not an issue. The problem has occurred with as much as 30G of space. I need to find out what is causing the problem. Please advise. The application is a power measurement application using 4461 DAQ card.  Also - no error messages are displayed, the running VI just stops.

[crossrulz]

Are you doing any file management with your TDMS file?  Things like closing the file and starting a new file every so often are important for these kinds of applications.

How are you logging the data?  Are you using the TDMS Streaming capability of DAQmx?

[mpatterson]

Currently I am using the multi-file option to create a new file when it reaches a certain size.  I have attached a screen shot of the settings.

[mpatterson]

I did get an error this last crash... It appears to be a memory issue.  Any recommendations on reclaiming memory or releasing memory?

[dkfire]

How much data are you storing local in the program?

Are you using array's?

Are they just getting bigger and bigger over time?

How are you adding data to array's?

Most of the times, that error comes when a program is building arrays all the time. At the end LabVIEW can't find RAM to build a bigger arrays.

[crossrulz]

There could be an issue the the Express VI converting your waveform data into the dreaded Dynamic Data Type, which is just causing more and more memory to be used.

So what I would recommend is use the DAQmx Configure Logging  VI to configure DAQmx to stream the data as you read straight to a TDMS file.  There are various other properties you can set to make the logging go across files.  You just set up the logging before running your task.

[mpatterson]

Thank you for your assistance. Your recommendations have been helpful.