Jennings

Hi, I'm trying to get the frequency spectrogram from a STFT, but I don't really understand how the frequency scale goes in the spectrogram. Under the default setting, the time steps are 128 and the frequency bins are 512, but that seems to give me double the correct frequency readings (150 instead of 70). If I change the frequency bins to 256, then I do get the correct frequency scale. Could someone please explain what frequency bins are in layman's terms, and why changing them from 512 to 256 gets me the "correct" scale and is this scale in kHz or how could I find that out? Thank you so much!

No, I don't have any daq hardware hooked up. I am taking a binary file and converting it to a wave file, which I want to analyze via the spectrogram function. Is there any caveats with this process?

Using the spectrogram function in Labview, I'm getting a weird cutoff in my graph. I'm plotting frequency v time, and on the frequency side, the graph goes up to a certain threshold, and then nothing above that threshold, even though I'm certain that I'm recording frequencies higher than that. Is there any known problem or limitations with the NI_gmath.lvlib:STFT Spectrogram.vi function? Any suggestions? Thanks! Jennings

Thanks a bunch i2dx. I tried the equivalent functions in Labview 8 and it works great now! Jennings

Thanks, but I feel like a complete doofus right now because I can't seem to find some of those functions (file open and file close icons seem different than mine). Are these Labview 8.0 functions?

Hi, I'm a new user to labview, and I'm having trouble reading a binary file that is 200MB in size. I'm not really familiar with Labview's programming language, but I used the File Open dialog function and it seems to work fine with files that are 150MB or smaller, but really slows down when they pass that limit. Should I use a different function, or split the file up somehow? Could anyone provide a step-by-step solution? Thanks very much, and I appreciate any input! My system specs: 512 x2 GB RAM 132 GB free HD space Jennings