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Entry  Thu Mar 22 14:36:01 2018, Phan Van Chuan, Read the CalibrateWaveform 
    Reply  Fri Mar 23 09:39:55 2018, Stefan Ritt, Read the CalibrateWaveform 
Message ID: 677     Entry time: Fri Mar 23 09:39:55 2018     In reply to: 676
Author: Stefan Ritt 
Subject: Read the CalibrateWaveform 

You don't have to read and calibrate the waveforms in your user code, but can rely on the DRS.cpp library to do that. Just look at the drs_exam.cpp program coming with the distribution. It uses the function b->GetWave() to retrieve the calibrated waveform. If you like, you can look into that function to learn how to apply the calibration, but I can tell you that it's a bit complicated. Since each event starts at an arbitrary stop cell in the DRS4, you have to "rotate" the calibration array. Then you do actually four calibrations in a row (cell, readout, gain and range).

Stefan

Phan Van Chuan wrote:

Helo
I'm building an application for reading waveforms from the DRS4 board to PC. However, I am having problems reading calibration data from EEPROM on DRS4 board. The calibration data is read through the function reference:
void DRSBoard :: ReadCalibration (void)
...
      ReadEEPROM (1, buf, 1024 * 32);
      for (i = 0; i <8; i ++)
         for (j = 0; j <1024; j ++) {
            fCellOffset [i] [j] = buf [(i * 1024 + j) * 2];
            fCellGain [i] [j] = buf [(i * 1024 + j) * 2 + 1] / 65535.0*0.4+0.7;
         }
      
      ReadEEPROM (2, buf, 1024 * 32);
      for (i = 0; i <8; i ++)
         for (j = 0; j <1024; j ++)
            fCellOffset2 [i] [j] = buf [(i * 1024 + j) * 2];
...
The Calibrate Waveform is performed by:
int DRSBoard::CalibrateWaveform(unsigned int chipIndex, unsigned char channel, unsigned short *adcWaveform, short *waveform, bool responseCalib, int triggerCell, bool adjustToClock, float threshold, bool offsetCalib)
.....
         for (j = 0; j < n_bins; j++) {
            value = adcWaveform[j] - fCellOffset[channel+chipIndex*9][(j*skip + triggerCell) % kNumberOfBins];
            value = value / fCellGain[channel+chipIndex*9][(j*skip + triggerCell) % kNumberOfBins];
            if (offsetCalib && channel != 8)
               value = value - fCellOffset2[channel+chipIndex*9][j*skip] + 32768;
...
. Because the calibration data reads incorrectly, the Calibrate Waveform does not do it.
Can read calibration data from EEPROM by any command via Oscilloscope application or DRS Command Line Interface application?
Thank you for your help!!!!

 

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