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  1. Hi All, I have an application in which I am using a FIFO queue. In this application, a bar code is read from a scanner, then data acquisition is initiated. Occasionally, (more often than I want it) the scanner output is incorrect, so it must be ignored. My thought is that, if I change the FIFO to LIFO in the queue, I will always dequeue the latest value that entered the queue. Can anyone help how to use LIFO? I could not find anything in the help menu. Thanks, Mac
  2. DAQ0.viHello All, I have a similar trigger issue, if someone can help, please. I want to acquire one second worth of (acceleration) data at the signal provided by a digital input., set to trigger on the rising edge. Here is what I have (see attachment), and it is not triggering. Thank you Maci DAQ0.vi
  3. Maci

    FFT resolution

    QUOTE (Neville D @ Jan 30 2009, 02:45 PM) Let paraphrase myself. I have more data points than I need for the spectrum I am after (3kHz). What I cannot find in the palettes is a function that will allow me to use up to 4 times the Nyquist frequency as a sampling rate. I can do this well in Excel, but the maximum number of points that the FFT algorithm in Excel is limited to 4096 points, which is not enough for the kind of frequency resolution I am after. Please, try again.
  4. Maci

    FFT resolution

    QUOTE (Norm Kirchner @ Jan 30 2009, 12:37 AM) Thank you, guys, for your prompt input. You all are saying the same thing and I agree. I think that I have enough data points to satisfy the basic Nyquist criterion, which requires that the data be sampled (at least) at twice the highest frequency of interest to avoid aliasing. In my case, I am sampling at 50kS/s. The FFT function I am using is giving me by default a spectrum with a range up to 25kHz. What I want to do is to reduce my frequency range to, say, 12.5kHz. This is in fact equivalent to sampling the data at 4 times the highest frequency of interest. So, I nead help locating a function in the LV-palette labyrinth which will allow me to input something (maximum frequncy, sampling rate, number of samples, or a combination of these). That way, I inclease the resolution. I hope my question is clearer.
  5. Hello everybody, I am using an FFT function to analyse a time series that I am reading from memory. I am using a FFT function that produces a spectrum whose frequency range complies with the Nyquist criterion. I want to lower my highest frequency of interest to increase the spectral resolution. Would someone point at a function in the function palette which allows to input the the maximum frequency. In my application, I need a resolution on the order of a fraction of a hertz. Please, help.
  6. QUOTE (Ton @ Jan 19 2009, 03:20 AM) Thank you for your input, Ton. I figured it out. Thank you, again
  7. QUOTE (Ton @ Jan 14 2009, 10:06 AM) Ton, is this kit something that is automatically part of the 8.6 version or is it a separate option that needs to be purchase? Our 8.6 package was a separately purchase all together.
  8. Greatings, we have started a motion control project in LabView 8.2. We kept going with this version until the project completion this past week. We now have Version 8.6, which we want (woke up!) to use instead of 8.2 for future upgrades of the design. When opening the RT vi, the follwing files could not be loaded. I was told that these are part the NI Drivers. I did install these drivers, and still could not be loaded. I looked them up using Windows explorer, but could not find them. Are these hidden files? Are they stored differently between the 8.2 and 8.6? Please, help. The RT vi attempts to loaded these files from <vilib>:\motion\softmotion\nisoftmotion\ ... by searching in C:\Programe Files\National Instruments\LabView 8.6\instr.lib\niTuner\dependency nimcDMTG_SetTimerPeriodAllAxes.vi nimcDMTG_DeleteInstance.vi nimcDMTG_StopCoordinate.vi nimcDMTG_SatrtCoordinate.vi nimcDMTG_LVSetCoordinatePositions.vi nimcDMTG_GetCoordTrajData.vi nimcDMTG_SetAxesInCoordinateSpace.vi nimcDMTG_CreateInstance.vi nimcDMTG_Execute.vi _nimcDMTG_CoordinateMoveType.vi _nimcDMTG_nimcDMTG_CS_Enum.ctl nimcDMTG_LVWriteCoordinateData.vi _nimcDMMain_CommInterface_Data.ctl
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