How to avoid one single large TDMS file?

[Coq_Rouge]

That was strange. I have several 6 and 7 GB files on my XP 32 bit computer. I am not sure why you have this trouble. But I think this is a OS problem. Not a Labview problem  

[Brad_K]

Hi Guosong,

Are you using the TDMS logging feature that is built into NI-DAQmx? If so, you should take a look at DAQmx Logging New Features - Split files, non-buffered logging, and pause/resume.

Brad

[EvenDeejay]

If your filesize is more than 4Gigabyte you cannot transfere it between systems with Fat32. Even though the file was created on a system with ntfs, you still cannot transfere it to a system that uses Fat32. I would recommend that you convert your Fat32 systems to NTFS, since Fat32 belong to the previous millenium.

[Guosong]

The system is already NTFS!!

[JLS]

Hi Guosong,

This is a fairly common issue whenever you're streaming data to disk a relatively high speeds - wanting to limit the size of a given file.

How about a simple flush/close and create/open new file periodically?

More specifically, if you're reading a known number of samples on each iteration, you can actually pre-compute the number of loop iterations between new file creations pretty easily.

Also, not sure what architecture you have going, but if you're streaming at a fairly high rate, it might be helpful to separate the DAQ read and TDMS write loops.  In the DAQ read loop you can read and enqueue the data to a queue, and in the TDMS write loop you can dequeue the data and then write it to TDMS.  You'd of course be doing your periodic flush/close, create/open in the TDMS loop.

In the end, you'll produce a series of TDMS files which are size limited to whatever you need.

Hope this helps!