skimber

Capability Questions for the USB Oscilloscope

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I work for an Electrical Engineering Program at a University and we are considering using the USB scopes from Digilent in one or more of our labs.  However, we need to know if they can do the following things:  Please note that I am not an Engineer, more of a procurement specialist.  I have done as much research as I can understand and have posted my findings, but I am not qualified to pull 100% reliable answers from the documentation, so any help is greatly appreciated.

1. The ability to display and capture (for lab reports) analog waveforms in the audio frequencies (22kHz+ up to 100KHz).
From the sales data sheet it appears that this is possible: 

Analog inputs go to 5MHZ: Two fully di­erential channels; 14-bit converters; 100 MSPS real-time sample rate
• 500uV to 5V/division; 1MΩ, 24pF inputs with 5MHz analog bandwidth

2. The ability to display and capture (for lab reports) spectral plots in the same band as above.
Again from the sales sheet, this appears to be possible:
 Real-time FFTs, XY plots, Histograms and other functions always available

3. The ability to average several spectral plots of the same signal to reduce noise in the plots.

4. The ability to generate white noise.

 

I have been unable to find anything concerning these last two needs from documentation I have been able to find on digilent.com  If anyone knows about these capabilities, I really appreciate the help.

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Hi skimber,

Great questions! I have temporarily moved this topic to this particular forum so that one of our users who knows these answers can find this topic more easily. I'll then move this topic back to the sales section (as that is the more appropriate section for users searching for similar sales answers).

Let me know if you have any more questions.

Thanks,
JColvin

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The software features can be tested without device in demo mode.

3. The Spectrum Analyzer interface has several averaging options:

  • Sample: The trace is updated after each sweep. 
  • Peak Hold Cont.: Continuous peak hold, keeps the maximum values for each bin from consecutive sweeps. 
  • Peak Hold: The trace is updated after the specified count of sweeps. 
  • Min Hold Cont.: Keeps continuously the minimum amplitude values for each bin from consecutive sweeps. 
  • Min Hold: The trace is updated after the specified count of sweeps. 
  • Linear RMS Average: The trace is updated after the specified count of sweeps with linear average of Vrms amplitudes. 
  • Linear dB Average: The trace is updated after the specified count of sweeps with linear average of dB amplitudes. 
  • Exp. RMS Average: Performs exponential averaging of Vrms amplitudes. It is calculated using the following formula: 
    Averagei = Rrms(Sweep)/Weight + Rms (Average)(i-1)*(Weight -1)/Weight  
  • Exp. dB Average: Performs exponential averaging of Vrms amplitudes. It is calculated using the following formula: 
    Averagei = dB(Sweep)/Weight  + dB (Average)(i-1)*(Weight -1)/Weight 

4. The analog waveform generator and digital pattern generator have noise option which outputs a pseudo random number generated in the device. The sample frequency/update rate can be also specified.

 

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