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ID Date Authordown Subject
  499   Sun Apr 3 22:34:28 2016 Abaz KryemadhiTrigger on the And of a positive and negative signal

Thanks, great!

Chris Thompson wrote:

No there are no other components. I put a photo of the inverter with its cables SMA and one end, BNC at the other. You can see it is very small. I glued the inverter to a piece of thin plywood, and fixed the cables to it before attempting to solder them to the pads on the ferite bead support

Abaz Kryemadhi wrote:

Thanks again,   this is very useful,  just another question did you put any other passive elements in the circuit for inverting the signal or just simply swaped the transformer connections? 

Chris Thompson wrote:

The coilcraft part number is: JA4220-ALB. Iordered two of them and they were sent as free samples. You might want to buy some slightly bigger ones. I found them so small it was very hard to solder the coax cable to the connectors. Since I got them, I managed to damage one as they are quite fragile! In the confirmation email I got there was some contact info which may be useful for you: "For help, contact Victoria Berner at 847-516-5551  vberner@coilcraft.com "  BTW every time I use this forum I'm told that my password is not valid. Each time I reset it according to the "Lost pasword preceedure. Then I can log on again. Its quite annoying.

Abaz Kryemadhi wrote:

Hi Chris,

 I am looking at Sensl SiPMs as well,  can you send the part number from Coilcraft?



Chris Thompson wrote:

I needed a fast pulse inverter in order to feed signals from the recent SensL SiPMs into a conventional CFD which only accepted negative signals. I got a very small ferite torridal transformer from Coilcraft and wired up to invert signals then inserted into in 50 ohm coax cable and it works fine. These things cost only a few cents each!

Abaz Kryemadhi wrote:

Thanks, that looks just fine.

Stefan Ritt wrote:

Here is one (SI 100): https://www.picoquant.com/products/category/accessories/adapters-splitters-cables-various-accessories-for-photon-counting-setups

Abaz Kryemadhi wrote:

Ok, thanks!  do you know an easy in-line inverter like mini-circuit or digikey?    Can also redesign the detector I gues to produce positive signals, just it might be easier if there was a simple inverter if you are aware of? thanks Abaz

Stefan Ritt wrote:

No. You have to use an inverter for one of your signals.


Abaz Kryemadhi wrote:

I would like to be able to trigger in this fashon:  channel 0 > 0.1 and. channel 1< -0.1,  because I have a positive and a negative signal.  Can DRS4 (5) Eval board do this kind of trigger?













  517   Wed Apr 27 20:04:12 2016 Abaz KryemadhiBest settings for time measurements

I am studing some pulses that are about 200-300 ns wide and a rise time of few ns,    which settings would be best for coincidence time measurements?

In some preliminary work I found for 700 MegaS the time measurement is better without time calibration (in -0.05 to 1V) rather than with time calibration in -0.5 to 0.5,  my pulses are about 60 mV.   Is it expected that always with time calibration time accuracy would be better or depends?   

Also I use this code snippet to find time for channel 1 and the same idea for chan. 2.

// find peak in channel 1 above threshold
      for (i=0 ; i<1022 ; i++)
         if (waveform[0][i] < threshold1 && waveform[0][i+1] >= threshold1) {
            tt1 = (threshold1-waveform[0][i])/(waveform[0][i+1]-waveform[0][i])*(time[0][i+1]-time[0][i])+time[0][i];




  727   Tue Jan 29 14:43:44 2019 Abaz KryemadhiROOT Macro for data acquired with the newest software


Is there a root macro for decoding binary data acquired with the newest software for single board or multi-boards daisy chained?



  747   Fri Mar 8 19:35:11 2019 Abaz KryemadhiROOT Macro for newest software

The older root macro did not work for me for data acquired with the newest software.

so for the newest software and multiple boards, I modified the read_binary.cpp into read_binary.C for those who like to use the root macro, see the attachment.  


Attachment 1: read_binary.C
   Name:           read_binary.C
   Created by:     Stefan Ritt <stefan.ritt@psi.ch>
   Date:           July 30th, 2014
   Modified By:    Abaz Kryemadhi
   Date:           March 7th, 2019
   Purpose:        Example program under ROOT to read a binary data file written 
                   by the DRSOsc program. Decode time and voltages from waveforms 
                   and display them as a graph. Put values into a ROOT Tree for 
                   further analysis.
                   To run it, do:
                   - Crate a file test.dat via the "Save" button in DRSOsc
                   - start ROOT (type root)
                   root [0] .L read_binary.C+
                   root [1] decode("test.dat");

#include <fcntl.h>
#include <unistd.h>
#include <math.h>

#include <string.h>
#include <stdio.h>
#include "TFile.h"
#include "TTree.h"
#include "TString.h"
#include "TGraph.h"
#include "TCanvas.h"
#include "Getline.h"
#include "TAxis.h"

typedef struct {
   char           tag[3];
   char           version;

typedef struct {
   char           time_header[4];

typedef struct {
   char           bn[2];
   unsigned short board_serial_number;

typedef struct {
   char           event_header[4];
   unsigned int   event_serial_number;
   unsigned short year;
   unsigned short month;
   unsigned short day;
   unsigned short hour;
   unsigned short minute;
   unsigned short second;
   unsigned short millisecond;
   unsigned short range;

typedef struct {
   char           tc[2];
   unsigned short trigger_cell;

typedef struct {
   char           c[1];
   char           cn[3];


//int main(int argc, const char * argv[])
void decode(char *filename) {

   FHEADER  fh;
   THEADER  th;
   BHEADER  bh;
   EHEADER  eh;
   TCHEADER tch;
   CHEADER  ch;
   unsigned int scaler;
   unsigned short voltage[1024];
   double waveform[16][4][1024], time[16][4][1024];
   float bin_width[16][4][1024];
   int i, j, b, chn, n, chn_index, n_boards;
   double t1, t2, dt;
   //char filename[256];
   char rootfile[256];
   int ndt;
   double threshold, sumdt, sumdt2;
   double sum, baseline, max,amplitude1,amplitude2, amplitude3,amplitude4;
   // open the binary waveform file
   FILE *f = fopen(filename, "rb");
   if (f == NULL) {
      printf("Cannot find file \'%s\'\n", filename);
    //open the root file
   strcpy(rootfile, filename);
   if (strchr(rootfile, '.'))
      *strchr(rootfile, '.') = 0;
   strcat(rootfile, ".root");
   TFile *outfile = new TFile(rootfile, "RECREATE");
   // define the rec tree
   TTree *rec = new TTree("rec","rec");
   rec->Branch("t1", time[0][0]     ,"t1[1024]/D");  
   rec->Branch("t2", time[0][1]     ,"t2[1024]/D");  
   rec->Branch("t3", time[0][2]     ,"t3[1024]/D");  
   rec->Branch("t4", time[0][3]     ,"t4[1024]/D");  
   rec->Branch("w1", waveform[0][0] ,"w1[1024]/D");
   rec->Branch("w2", waveform[0][1] ,"w2[1024]/D");
   rec->Branch("w3", waveform[0][2] ,"w3[1024]/D");
   rec->Branch("w4", waveform[0][3] ,"w4[1024]/D");
   rec->Branch("amplitude1", &amplitude1,"amplitude1/D");
   rec->Branch("amplitude2", &amplitude2,"amplitude2/D");
   rec->Branch("amplitude3", &amplitude3,"amplitude3/D");
   rec->Branch("amplitude4", &amplitude4,"amplitude4/D");
   // create canvas
   TCanvas *c1 = new TCanvas();
   // create graph
   TGraph *g = new TGraph(1024, (double *)time[0][0], (double *)waveform[0][0]);

   // read file header
   fread(&fh, sizeof(fh), 1, f);
   if (fh.tag[0] != 'D' || fh.tag[1] != 'R' || fh.tag[2] != 'S') {
      printf("Found invalid file header in file \'%s\', aborting.\n", filename);
   if (fh.version != '2') {
      printf("Found invalid file version \'%c\' in file \'%s\', should be \'2\', aborting.\n", fh.version, filename);

   // read time header
   fread(&th, sizeof(th), 1, f);
   if (memcmp(th.time_header, "TIME", 4) != 0) {
      printf("Invalid time header in file \'%s\', aborting.\n", filename);

   for (b = 0 ; ; b++) {
      // read board header
      fread(&bh, sizeof(bh), 1, f);
      if (memcmp(bh.bn, "B#", 2) != 0) {
         // probably event header found
         fseek(f, -4, SEEK_CUR);
      printf("Found data for board #%d\n", bh.board_serial_number);
      // read time bin widths
      memset(bin_width[b], sizeof(bin_width[0]), 0);
      for (chn=0 ; chn<5 ; chn++) {
         fread(&ch, sizeof(ch), 1, f);
         if (ch.c[0] != 'C') {
            // event header found
            fseek(f, -4, SEEK_CUR);
         i = ch.cn[2] - '0' - 1;
         printf("Found timing calibration for channel #%d\n", i+1);
         fread(&bin_width[b][i][0], sizeof(float), 1024, f);
         // fix for 2048 bin mode: double channel
         if (bin_width[b][i][1023] > 10 || bin_width[b][i][1023] < 0.01) {
            for (j=0 ; j<512 ; j++)
               bin_width[b][i][j+512] = bin_width[b][i][j];
   n_boards = b;
   // initialize statistics
   ndt = 0;
   sumdt = sumdt2 = 0;
   // loop over all events in the data file
   for (n=0 ; ; n++) {
      // read event header
      i = (int)fread(&eh, sizeof(eh), 1, f);
      if (i < 1)
      printf("Found event #%d %d %d\n", eh.event_serial_number, eh.second, eh.millisecond);
      // loop over all boards in data file
      for (b=0 ; b<n_boards ; b++) {
         // read board header
         fread(&bh, sizeof(bh), 1, f);
         if (memcmp(bh.bn, "B#", 2) != 0) {
            printf("Invalid board header in file \'%s\', aborting.\n", filename);
         // read trigger cell
         fread(&tch, sizeof(tch), 1, f);
         if (memcmp(tch.tc, "T#", 2) != 0) {
            printf("Invalid trigger cell header in file \'%s\', aborting.\n", filename);

         if (n_boards > 1)
            printf("Found data for board #%d\n", bh.board_serial_number);
         // reach channel data
         for (chn=0 ; chn<4 ; chn++) {
            // read channel header
            fread(&ch, sizeof(ch), 1, f);
            if (ch.c[0] != 'C') {
               // event header found
               fseek(f, -4, SEEK_CUR);
            chn_index = ch.cn[2] - '0' - 1;
            fread(&scaler, sizeof(int), 1, f);
            fread(voltage, sizeof(short), 1024, f);
            for (i=0 ; i<1024 ; i++) {
               // convert data to volts
               waveform[b][chn_index][i] = (voltage[i] / 65536. + eh.range/1000.0 - 0.5);
               // calculate time for this cell
               for (j=0,time[b][chn_index][i]=0 ; j<i ; j++)
                  time[b][chn_index][i] += bin_width[b][chn_index][(j+tch.trigger_cell) % 1024];
         // align cell #0 of all channels
         t1 = time[b][0][(1024-tch.trigger_cell) % 1024];
         for (chn=1 ; chn<4 ; chn++) {
            t2 = time[b][chn][(1024-tch.trigger_cell) % 1024];
            dt = t1 - t2;
            for (i=0 ; i<1024 ; i++)
               time[b][chn][i] += dt;
         t1 = t2 = 0;
         threshold = 0.3;
         // find peak in channel 1 above threshold
         for (i=0 ; i<1022 ; i++)
            if (waveform[b][0][i] < threshold && waveform[b][0][i+1] >= threshold) {
               t1 = (threshold-waveform[b][0][i])/(waveform[b][0][i+1]-waveform[b][0][i])*(time[b][0][i+1]-time[b][0][i])+time[b][0][i];
         // find peak in channel 2 above threshold
         for (i=0 ; i<1022 ; i++)
            if (waveform[b][1][i] < threshold && waveform[b][1][i+1] >= threshold) {
               t2 = (threshold-waveform[b][1][i])/(waveform[b][1][i+1]-waveform[b][1][i])*(time[b][1][i+1]-time[b][1][i])+time[b][1][i];
         // calculate distance of peaks with statistics
         if (t1 > 0 && t2 > 0) {
            dt = t2 - t1;
            sumdt += dt;
            sumdt2 += dt*dt;
     //Find baseline for channel 3 to get amplitude for ch3 
      for (i=0 ; i<10; i++) {
     //Find amplitude for channel 3 (this is example channel )
      for (i=0 ; i<1022; i++) {
         if (waveform[b][2][i]>max) {
     // fill root tree

  //Uncomment the following to see couple waveforms of voltage vs time
      // fill graph
      for (i=0 ; i<1024 ; i++)
         g->SetPoint(i, time[b][2][i], waveform[b][2][i]);
      // draw graph and wait for user click
... 20 more lines ...
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