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Showing results for tags 'channel'.
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When using the scope from the Waveforms IDE, I can't get a visual of Channel 2. (Channel 1 works fine) I've tried using multiple USB ports and other computers. When I run calibration for the oscilloscope I get the following error message: "Check the connections!! The measured voltage on Oscilloscope Channel 2 is between: 30.269009276 V and 30.275477712 V. But it should be around: 0 V. It might be that the Arbitrary Waveform Generator 1 Offset is not calibrated correctly." I don't think the waveform is the issue, it reads as expected on channel 1. I could use some help.
I am sending synchronized, phase-shifted pulses with the AWG on both AnalogOut channels on the Discovery2, using a custom application I'm writing in python. I am feeding the AnalogOut directly back to the AnalogIn with no additional hardware involved. I am trying to read the two AWG signals using the AnalogIn channels, but I can't get Channel 2 to report the signal. Instead, both signals are adding together and displaying as coming from channel 1, with the expected channel 2 signal showing up as negative voltages on channel 1. How do I separate the two signals? This is the chunk of code I am using to record samples and plot (mostly copied from the provided code samples): #configure analog in self.dwf.FDwfAnalogInFrequencySet(hdwf, c_double(int(hzSys.value/(100*self.xRate)))) self.dwf.FDwfAnalogInBufferSizeSet(hdwf, c_int(4000)) self.dwf.FDwfAnalogInChannelEnableSet(hdwf, c_int(0), c_bool(True)) self.dwf.FDwfAnalogInChannelRangeSet(hdwf, c_int(0), c_double(5)) self.dwf.FDwfAnalogInChannelEnableSet(hdwf, c_int(1), c_bool(True)) self.dwf.FDwfAnalogInChannelRangeSet(hdwf, c_int(1), c_double(5)) #begin acquisition self.dwf.FDwfAnalogInConfigure(hdwf, c_int(1), c_int(1)) #collect data sts = c_int() while True: self.dwf.FDwfAnalogInStatus(hdwf, c_int(1), byref(sts)) if sts.value == DwfStateDone.value : break time.sleep(0.1) #read data rg1 = (c_double*1000)() #rg = pointer to allocated buffer to copy the acquisition data rg2 = (c_double*1000)() #rg = pointer to allocated buffer to copy the acquisition data self.dwf.FDwfAnalogInStatusData(hdwf, c_int(0), rg1, len(rg1)) # get channel 1 data self.dwf.FDwfAnalogInStatusData(hdwf, c_int(1), rg2, len(rg2)) # get channel 2 data #set up plot self.canvasX.figure.clear() plt1 = self.canvasX.figure.add_subplot(211) plt2 = self.canvasX.figure.add_subplot(212) #plot data rgpy1=[0.0]*len(rg1) rgpy2=[0.0]*len(rg2) for i in range(0,len(rgpy1)): rgpy1=rg1 rgpy2=rg2 plt1.plot(rgpy1, 'b') plt2.plot(rgpy2, 'r') self.canvasX.draw()