DRS4 Forum
  DRS4 Discussion Forum, Page 14 of 40  Not logged in ELOG logo
ID Date Author Subject
  531   Wed Jun 29 09:10:01 2016 Stefan RittNegative input signals

Hello everybody,

I get often asked if the DRS4 evaluation board can accomodate negative input pulses going to -1V. This is unfortunately not possible, since the board is mainly for evaluation of the DRS4 chip and should not be seen as a complete oscilloscope with flexible input stage. So the maximum it can do is -0.5V to +0.5V or 0V to 1V. For -1V signals, one can use however a passive inverter like this one:

http://www.phillipsscientific.com/pdf/460ds.pdf

And for signals going furhter (-2V, -10V) one can use a passive attenuator like this one:

http://www.pomonaelectronics.com/pdf/d4108_K5513_101.pdf

 

Best regards,

Stefan

 

  530   Wed Jun 15 14:49:00 2016 Stefan Rittproblems of DRS4

1. Simultaneous writing and reading is not possible with the DRS4 chip. The manual says differently on p. 14, but due to a bug in the chip waveforms get clipped at the end if one does that. We hopt to fix this problem in a future version of the chip.

2. You can cascade 2,4 or 8 channels. If you cascade 8 channels and run at 1 GSPS, you digitize a window of 8 us. If you have 16 signals, you then need 16 chips.

/Stefan

Michael wrote:

Hi

I want to use DRS4 to digitize 16 channels of signals. The width of signal is about 20 ns, with frequency of 50Hz. The time differences between these 16 signals are not constant, arranging from 3us to 0. I am confused about this in some aspects.

  1. Can I use SIMULTANEOUS WRITINT AND READING to realize this? I saw the VHDL program, and if I understand it correctly, it did not work at this state.
  2. Or sampling at 1GSPS, using CASCADING OF CHANNELS, I can sample signal at most 4us or 8us, then digitizing all signals of one chip. Have you tested 4 or more channels cascading before?

Besides, any advice will be helpful!

Thank you.

 

  Draft   Sun Jun 12 08:49:54 2016 Michaelproblems of DRS4

Hi

I want to use DRS4 to digitize 16 channels of signals. The width of signal is about 20 ns, with frequency of 50Hz. The time differences between these 16 signals are not constant, arranging from 3us to 0. I am confused about this in some aspects.

  1. Can I use SIMULTANEOUS WRITINT AND READING to realize this? I saw the VHDL program, and if I understand it correctly, it did not work at this state.
  2. Or sampling at 1GSPS, using CASCADING OF CHANNELS, I can sample signal at most 4us or 8us, then digitizing all signals of one chip. Have you tested 4 or more channels cascading before?

Besides, any advice will be helpful!

Thank you.

  528   Sun Jun 12 08:45:52 2016 Michaelproblems of DRS4

Hi

I want to use DRS4 to digitize 16 channels of signals. The width of signal is about 20 ns, with frequency of 50Hz. The time differences between these 16 signals are not constant, arranging from 3us to 0. I am confused about this in some aspects.

  1. Can I use SIMULTANEOUS WRITINT AND READING to realize this? I saw the VHDL program, and if I understand it correctly, it did not work at this state.
  2. Or sampling at 1GSPS, using CASCADING OF CHANNELS, I can sample signal at most 4us or 8us, then digitizing all signals of one chip. Have you tested 4 or more channels cascading before?

Besides, any advice will be helpful!

Thank you.

  527   Wed Jun 1 23:16:01 2016 Stefan Rittproblems when stop cell >= 767 ??

I cannot confirm the story with the "stop capacitor > 767". It can be seen from your plots that the distribution of stop cells are even, no holes or bins with double height.

There is an issue with cell 767, but this is when one tries to do simultaneous reading/writing to the chip. This does not really work as writen in the data sheet. Waveforms sometimgs get cut off at cell 767. But the stop cell is always correct, otherwise one could not calibrate the data. If you use the evaluation board for example, which is perfectly calibrated, and introduce an "artifical" shift like

if stop cell > 767 then
  stop cell = stop cell + 1

then you would see that the voltage calibration would become wrong and very noisy.

Stefan

Dominik Neise wrote:

Hello Stefan,

some colleages told me a story, I was neither able to confirm nor find anything in the datsheet about. According to them:

For some internal reason of the DRS4, if the “stop capacitor” of the DRS4 is >= 767, the true stop channel is one before the stop channel read from the DRS4. In other words, the stop channel which returns the DRS4 shifts after sampling to the capacitor ID 766.

Can you confirm that, or even say a few words about that matter?

I wanted to confirm this by plotting the stop cell distribution for random triggered data, taken with one of the FACT boards. I assumed (possibly misunderstanding the matter), that this would lead to missing values in the area of stop cell 767, but cannot see any significant excess or lack of entries in that area.

 

 

  526   Wed Jun 1 22:29:01 2016 Dominik Neiseproblems when stop cell >= 767 ??

Hello Stefan,

some colleages told me a story, I was neither able to confirm nor find anything in the datsheet about. According to them:

For some internal reason of the DRS4, if the “stop capacitor” of the DRS4 is >= 767, the true stop channel is one before the stop channel read from the DRS4. In other words, the stop channel which returns the DRS4 shifts after sampling to the capacitor ID 766.

Can you confirm that, or even say a few words about that matter?

I wanted to confirm this by plotting the stop cell distribution for random triggered data, taken with one of the FACT boards. I assumed (possibly misunderstanding the matter), that this would lead to missing values in the area of stop cell 767, but cannot see any significant excess or lack of entries in that area.

 

  525   Thu May 12 12:38:17 2016 Stefan RittDRS4 Macro to save events

Dear Maksat,

If your car does not run, and you call the car dealer and tell him "my car does not run", what will the car dealer ask you? Eh... ? Right ! He will ask "what are the symptoms, what did you try, what did and what did not work". Here it's the same. "was not able to get it work" is not a valid statement, since I have absolutely no idea what did not work and what you did try.

The official way is to follow the instruction in the evlauation board manual on section 2.4 - Installation under Linux. If that does not work, please be a bit more precise what errors you get.

Cheers,
Stefan

Maksat wrote:

Dear Stefan,

I am trying to setup DRS inside radiation enclosure and would like to write a simple script that will automatically save certain number of events.

Could you please point to me an example that can I use for Mac OS? I saw there is drs_exam.cpp in the directory but was not able to get work in Mac OS. Any help would be greatly appreciated.

Thanks

 

 

 

  524   Thu May 12 08:16:41 2016 Stefan RittProblem For Software Download

Can you tell me (screendump) what is the problem on the web site https://www.psi.ch/drs/software-download ? It should redirect you to

https://www.dropbox.com/sh/qul1cgtm4x7zx13/AADKQ-qGQGdAHPu6OR3vTNY0a?dl=0

for the Windows download.

I cannot send executables via email, that won't go though any spam filter.

Stefan

Yu wrote:

Hi

 I can't download the software for windows on this website 'www.psi.ch/drs/software-download', there is some mistake when i click on download. 

 If convenient, can you send the software Version 5.0.5 for windows to me? My E-mail address is 'yuhaiyang421@163.com'. Thank you!

 

Best Regards

Yu

 

  523   Thu May 12 05:18:47 2016 YuProblem For Software Download

Hi

 I can't download the software for windows on this website 'www.psi.ch/drs/software-download', there is some mistake when i click on download. 

 If convenient, can you send the software Version 5.0.5 for windows to me? My E-mail address is 'yuhaiyang421@163.com'. Thank you!

 

Best Regards

Yu

  522   Wed May 11 15:48:57 2016 SANDJONG Saturnin OrlyProbléme de Calibration de la DRS4

Bonjour, Je suis en stage dans un laboratoire ou on utilise pour echantillonnage des données, une cartes DRS4 5GSPS avec 1024 cell, mon probléme réside dans la partie Calibration en tension selon l'article "Novel Calibration Method for Switched Capacitor Arrays Enables Time Measurements with Sub-Picosecond Resolution". 

En fait je ne comprends pas précisément ces 3 parties de la calibration en tension. Quelqu'un pourras t-il s'il vous plait m'expliquer assez clairement avec des exemples comment il faut s'y prendre? 

Merci et bien Cordialement. 

  521   Wed May 11 04:01:14 2016 MaksatDRS4 Macro to save events

Dear Stefan,

I am trying to setup DRS inside radiation enclosure and would like to write a simple script that will automatically save certain number of events.

Could you please point to me an example that can I use for Mac OS? I saw there is drs_exam.cpp in the directory but was not able to get work in Mac OS. Any help would be greatly appreciated.

Thanks

 

 

  520   Mon May 2 14:31:28 2016 Dmitry Hitstwo DRS4 boards configuration with 2048 samples each

Hi Stefan

Any chance you have time to fix the software for multiboard configuration with 2048 samples each. I tried 5.0.5, but drsosc still shows only half of the waveform.

Dmitry

Stefan Ritt wrote:

The multi-board mode has never been tested with 2048 samples, so is very likely not to work. I don't know yet how much work this will be to fix, but I'm on a business trip the next three weeks and probably will only have time to look at it when I return.

Stefan

Dmitry Hits wrote:

Dear Stefan,

I daisy-chained two boards (master sn#: 2514 - slave sn#: 2513) each with 2048 samples. However, when I use drsosc and put check mark in "configure multi-board daisy-chain" I see only 1024 samples. Namely, the first 1024 samples, the last part is missing. When I remove this check mark, I see all 2048 samples. Is there a simple software fix for this or is it a more involved firmware limitation? 

Other parameters: software version: 5.0.4, firmware version 21305, configured for 0.7 GSPS, display at 500 ns/div

Thank you,

Dmitry Hits.

 

 

  519   Thu Apr 28 15:47:53 2016 Stefan RittNew software version and binary format

A new software version 5.0.5 has been released today. This fixes a few bugs in multi-board configurations, and adds saving of the scaler values into XML and binary files. Please note that the binary file format has been changed for that. The new format is described in an updated manual (page 25), and reflected in a new read_binary.cpp program contained in the distribution.

/Stefan

  518   Thu Apr 28 15:46:34 2016 Stefan RittBest settings for time measurements

The DRS4 chip has been designed to work best at high sampling speeds. At 700 MSPS, the chip is at it's limit and timing is very poorr (ns?). In order to get good timing, run it at least at 2 GSPS.

Stefan

Abaz Kryemadhi wrote:

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];
            break;
         }

 

Thanks!

Abaz

 

  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];
            break;
         }

 

Thanks!

Abaz

  516   Wed Apr 27 09:51:37 2016 Toshihiro Nonakaserial number problem

The serial number has been fixed by using drscl. Thank you!

Stefan Ritt wrote:

If dis- and reconnecting the board does not help, there is the (small) chance that the serial number got erased in the board. You can re-set it with the "drscl" command line tool:

$ drscl
Found DRS4 board 0 on USB, serial #0, firmware revision 21305
B0> serial 2172

 

Toshihiro Nonaka wrote:

Dear all,

I'm using 3 DRS boards simultaneously and their serial numbers are 2169, 2170, 2172 respectively.

Recently however,  I obtain serial number "0" by DRSBoard::GetBoardSerialNumber() for #2172 board.

Data taking can be done without any problems, but I'd like to know what is happening.

Any advice?

Thank you.

Toshihiro Nonaka

 

 

  515   Wed Apr 27 09:04:01 2016 Stefan Rittserial number problem

If dis- and reconnecting the board does not help, there is the (small) chance that the serial number got erased in the board. You can re-set it with the "drscl" command line tool:

$ drscl
Found DRS4 board 0 on USB, serial #0, firmware revision 21305
B0> serial 2172

 

Toshihiro Nonaka wrote:

Dear all,

I'm using 3 DRS boards simultaneously and their serial numbers are 2169, 2170, 2172 respectively.

Recently however,  I obtain serial number "0" by DRSBoard::GetBoardSerialNumber() for #2172 board.

Data taking can be done without any problems, but I'd like to know what is happening.

Any advice?

Thank you.

Toshihiro Nonaka

 

  514   Wed Apr 27 08:14:14 2016 Toshihiro Nonakaserial number problem

Dear all,

I'm using 3 DRS boards simultaneously and their serial numbers are 2169, 2170, 2172 respectively.

Recently however,  I obtain serial number "0" by DRSBoard::GetBoardSerialNumber() for #2172 board.

Data taking can be done without any problems, but I'd like to know what is happening.

Any advice?

Thank you.

Toshihiro Nonaka

  513   Tue Apr 26 13:42:42 2016 Stefan RittDRS4 purchase information

Just be patient. Anita is not at work this week.

Konstantin Gusev wrote:

    Hi,

 I can't contact with Anita Van Loon about DSR4 chip's price and delivery.

Did you still sell it? Can you provide me this information?

 

  512   Tue Apr 26 09:54:16 2016 Stefan RittNegative fCellDT values from GetTimeCalibration()

I just realized that the negative bin widht is not explicitly mentioned in the quoted paper. So let me explain it here:

The negative value of cell 498 is correct and "real" in the sense that the signal is first captured in cell 498 and later in cell 497. This is due to the exact layout of the cells on the chip and the input signal. Cell 498 is simply much closer to the input, so sees the signal earlier than cell 497, even if it's triggerd after cell 497. So nothing to worry about.

Stefan

Daniel Stricker-Shaver wrote:

Hi Kyle,

If I remember right the negative sampling width happens only for 498 and at high sampling speeds. It is described in a paper from Stefan:

http://arxiv.org/pdf/1405.4975.pdf

or

“Novel Calibration Method for Switched Capacitor Arrays Enables Time Measurements With Sub-Picosecond Resolution”( IEEE Transactions on Nuclear Science 61 (2014),Nr. 6, 3607–3617)

Kyle Weinfurther wrote:

Hello Stefan,

I am using four DRS4 v5 eval boards to digitize 16 channels of data. I have recently changed from saving the timing information of the waveform using GetTime() to GetTimeCalibration(). When changing over, I noticed that some values for fCellDT for cell 498 are negative. Over the 16 channels used, 4 of them have negative time bin widths for cell 498 while the other 12 channels are very close to 0 (in the ~10 ps range). One of the eval boards has no negative fCellDT whereas the other three boards have one or two channels with negative values.

Upon further inspection, I checked the time between samples of GetTime() and found the same results in cell 498. After finding this, I did a timing calibration again with CalibrateTiming() even though in a different post on the discussion forum you said it was valid for a wide range of temperatures and a long time (years). This still allowed the negative fCellDT values to persist.

Is this a common occurance? If so, is there a method to fix this issue? Is there a reason for cell 498 to have a small value for fCellDT? I searched the discussion forum and did not find anything relating to this issue.

Attached are a couple waveform traces using GetTime() zoomed in on cell 498.

Thanks,

Kyle Weinfurther

 

 

ELOG V3.1.4-80633ba