Dear Stefan,

I am using an DRS4 board to record the signals from an plastic scintillator detector. It was working really good, yet a few day ago the signals became "not right". When I checked the signal using an oscilloscope it show the normal signals previously recorded. The signal amplitude are clearly reduced (from 0.3 in oscilloscope to lower than 0.1 in DRS4). Can you show me how to show this problem?

Thank you very much!

Best Regards,

Thien 

https://bitbucket.org/ritt/drs4eb

Hi, 

The board is modified (and checks out with the DRSScope program). Could you please point me to the drs_exam_2048.cpp file? I can't seem to fine the most up-to-date git repository....

Thanks, 

Yoni

First you need a board which is modified in hardware to support channel cascading. Basically there are internal resistors which connect each input connector to two channels. You have to specify this when you order the board. Then you can use the new drs_exam_2048.cpp file contains in the git repository which correctly configures and reads out the board in two-channel cascading mode. Putting all 8 channels together is not supported by the evaluation boards.

Stefan

Hi, 

I'm trying to do the same thing (get 1 channel with 8192 bins), but I'm having some trouble with it. When I call SetChannelConfig(0, 8, 1) as suggeted, I get output that looks like noise on all readouts. Could you please explain what is supposed to happen in this case? 

I will happily write the code to combine the channels correctly (and debug it) if I can understand what needs to be done. 

(I should mention that my primary concern is a MATLAB interface which I have already written and don't mind sharing when it's complete). 

Yoni Sher

Indeed the code does not work for the current evaluation board, it has been written for a previous version and never been updated. Please use following code to enable the external trigger

   /* use following lines to enable the external trigger */
   if (b->GetBoardType() >= 8) {        // Evaluaiton Board V4&5
      b->EnableTrigger(1, 0);           // enable hardware trigger
      b->SetTriggerConfig(1<<4);        // set external trigger as source
   } else {                             // Evaluation Board V3
      b->EnableTrigger(1, 0);           // lemo on, analog trigger offf
   }

Please also make sure that the signal on the external trigger input is strong enough. You need at least 2.5V at 50 Ohms, and not every driver is capable of driving 50 Ohms.

Stefan

We have been able to use the DRS4 using a Raspberry Pi but we have not been able to use the external trigger. What we are doing is basically comment out the code shown below (downloaded from PSI) to use the hardware trigger and uncomment the code to use the external trigger. We have not been able to get external trigger to work. Could you see what could be wrong?

/* use following line to turn on the internal 100 MHz clock connected to all channels  */
   //b->EnableTcal(1);

   /* use following lines to enable hardware trigger on CH1 at 50 mV positive edge */

   /*
   if (b->GetBoardType() >= 8) {        // Evaluaiton Board V4&5
      b->EnableTrigger(1, 0);           // enable hardware trigger
      b->SetTriggerSource(1<<0);        // set CH1 as source
   } else if (b->GetBoardType() == 7) { // Evaluation Board V3
      b->EnableTrigger(0, 1);           // lemo off, analog trigger on
      b->SetTriggerSource(0);           // use CH1 as source
   }
   b->SetTriggerLevel(0.05);            // 0.05 V
   b->SetTriggerPolarity(false);        // positive edge
   */

   /* use following lines to set individual trigger elvels */
   //b->SetIndividualTriggerLevel(1, 0.1);
   //b->SetIndividualTriggerLevel(2, 0.2);
   //b->SetIndividualTriggerLevel(3, 0.3);
   //b->SetIndividualTriggerLevel(4, 0.4);
   //b->SetTriggerSource(15);

   b->SetTriggerDelayNs(0);             // zero ns trigger delay

   /* use following lines to enable the external trigger */
   if (b->GetBoardType() == 8) {     // Evaluaiton Board V4
      b->EnableTrigger(1, 0);           // enable hardware trigger
      b->SetTriggerSource(1<<4);        // set external trigger as source
   } else {                          // Evaluation Board V3
      b->EnableTrigger(1, 0);           // lemo on, analog trigger off
    }

Dear Steffan:

We have been able to use the DRS4 using a Raspberry Pi but we have not been able to use the external trigger. What we are doing is basically comment out the code shown below (downloaded from PSI) to use the hardware trigger and uncomment the code to use the external trigger. We have not been able to get external trigger to work. Could you see what could be wrong?

Thanks

Diego

/* use following line to turn on the internal 100 MHz clock connected to all channels  */
   //b->EnableTcal(1);

   /* use following lines to enable hardware trigger on CH1 at 50 mV positive edge */

   /*
   if (b->GetBoardType() >= 8) {        // Evaluaiton Board V4&5
      b->EnableTrigger(1, 0);           // enable hardware trigger
      b->SetTriggerSource(1<<0);        // set CH1 as source
   } else if (b->GetBoardType() == 7) { // Evaluation Board V3
      b->EnableTrigger(0, 1);           // lemo off, analog trigger on
      b->SetTriggerSource(0);           // use CH1 as source
   }
   b->SetTriggerLevel(0.05);            // 0.05 V
   b->SetTriggerPolarity(false);        // positive edge
   */

   /* use following lines to set individual trigger elvels */
   //b->SetIndividualTriggerLevel(1, 0.1);
   //b->SetIndividualTriggerLevel(2, 0.2);
   //b->SetIndividualTriggerLevel(3, 0.3);
   //b->SetIndividualTriggerLevel(4, 0.4);
   //b->SetTriggerSource(15);

   b->SetTriggerDelayNs(0);             // zero ns trigger delay

   /* use following lines to enable the external trigger */
   if (b->GetBoardType() == 8) {     // Evaluaiton Board V4
      b->EnableTrigger(1, 0);           // enable hardware trigger
      b->SetTriggerSource(1<<4);        // set external trigger as source
   } else {                          // Evaluation Board V3
      b->EnableTrigger(1, 0);           // lemo on, analog trigger off
    }

This feature is not yet implemented. The (disabled) software swtich is more like a kind of a reminder to myself to work on that one day...

Thank you very much !! All my fault for I thought it too comlicated. Thank you sincerely!

Remove the check mark from the "Lock" box and enter a different value in the sampling speed box and hit return.

OK!Thank you! One more question,when I use the Oscillocope ,I found that the actual speed is a constant value of 1.007G,how can change this speed.

The command line interface is more a debugging tool for experts, and you are not supposed to use it except to test the connection to the evaluation board. The programs for the user are the DRS Oscilloscope and the drs_exam.cpp example program to read out the board with your own program.

Stefan

Hello! I'm using DRS4 evaluation board V5 with the drs command line interface,but the mannal only explained the meaning of the command--"info".And I can't get the hang of the use of other commands through "help",so is there anywhere can I learn more about other commands?Or I can only learn it through the datasheet of DRS4 chip.

Thanks!

The Display window in the Oscilloscope software shows averaging capabilites but I have not been able to activate these. Is it possible to activate averaging with the existing oscilloscope software? Thanks

Think about: How would you make a coincidence (AND) between two edges? Since an edge is infinitesimally small, there is no way to make a meaningful coincidence between edges. Therefore, the DRS4 EB firmware makes a simple AND of levels. If you trigger on rising signals and do an AND, then you get a trigger if both values are above their threshold. For falling edge trigger (arrow goes down in the trigger configuration) the board triggers when both signals are BELOW the trigger threshold. So actually the singnal which crosses the threshold last determines the timing of the trigger. I see no other way how to implement an AND.

Stefan

Hi!

I'm using the DRSOsc program, and I have a question that I need a bit clarified;

When triggering using AND between two channels, am I then triggering on rising/falling edge of both channels, or on the actual values?

That is, is it the change in value that it triggers on, or when the actual value goes above a certain threshold?

Using AND, it seems like I get a trigger when one (CH2) is above its trigger value (sometimes quite far above), and the other (CH1) changes to go above its trigger value. This works for my purposes, which is nice, but I just want to be sure I understand why it works. Ideally, I'd like to trigger when one of my channels is above a certain value, and the other has a rising edge above a certain value.

I'm sorry if it's a silly question! I've just noticed that the Keysight oscilloscopes I've used can only do one channel with a rising edge at a time when doing a logic trigger, and I thought the same thing might be going on in the background here (which would be ideal for my purposes).

Kind regards,

Håkan Wennlöf

Thank you for your reply!

No this is not possible. But you can delay your signal externally (like with a delay cable or electronically) and then send the dealyed signal to the evaluation board for triggering.

Stefan

Hello.

I have a simple question, can I set SetTriggerDelayNs() more than 1631 ns?

I need to set this delay to about 5 us... Can I do this? 

Thank you in advance! 

With best regards, 

Vadym

Have you tried as root? Maybe you miss some permissions.

Stefan