Dear DRS4 team,

I'm trying to troubleshoot some odd spike behavior. If I run the ADC and SR CLK at 16 MHz (behavior also seen at 33 MHz) we get very noisy data (post-calibration) with periodic spikes.

In the below plot

• CH0 & CH1 are muon pulses from a scintillator + SiPM detector
• CH8 is a 25 MHz sinewave (in phase with all generated board clocks)
• Transparent mode = ON
• ROI = OFF, "full readout mode", first sample = cell 0
• DRS REFCLK = 1 MHz (2 GS/s)
• ADC & SR CLK = 16 MHz, 0 deg. offset

After I modify some clock settings, things seem to improve dramatically, and the spike behavior changes

• ADC and SR CLK = 15 MHz, 0 deg. offset
• Transparent mode = ON
• ROI = ON (just for testing purposes)
• Add 1.064 ns skew to DRS REF CLK
• NOTE: Unfortunately due to a design mishap, the ADC and FPGA clock use a phase-locked output pair on our clock synthesis chip, so we cannot fine-tune the skew for it.

Observed differences

• Spike polarity seems inverted
• Spikes limited to smaller number of cells now?
• Spike amplitude reduced
• Overall baseline variance seems better
• New large positive spike artifact on CH0 that seems inverted on CH1
• CH8 seems unaffected by large spikes?

Artifacts seem related to clock configuration, but I am sort of in the dark on what might be happening from a first-principles point of view. Any tips?

Warm regards,

Sean

Hi,

I have been collecting some date using the DRS4 board at a trigger rate of 10-20 Hz,    I only need the timestamp and the amplitude, is there anyway to select only these two live as the data comes in to be stored. 

Alternatively,  What's the maximum file size or maximum number of events I can store in one binary file in linux. 

Thanks,

Best,

Abaz

Hi there,

Recently I bought a 5GSPS evaluation board with 2048 sampling points.
I want to read 4 inputs of the evaluation bord ar 5 GSPS or 2.5GSP and use an external trigger.
I've checked your website and download drs-5.0.5 which contains the source code in C. It seems that the file drs_exam.cpp can do what I am looking for.
So far I could make and compile the project in Linux Ubuntu, but I couldn't compile it in Windows 10.  I've used Cygwin64 to compile the project in windows 10.

I have the following questions:

1- Since I only need to compile the drs_exam.cpp file, could please help me with how can I compile it directly(without making the entire project). Or tell me which version of Wxwidget and libusb I have to install.

2- If you have any sample code that can read 4 inputs with an external trigger, please tell me where can I find it.

In the end, I want to write a wrapper on this C file(which returns digitized data) and run it from my python program. Thank you in advance.
Best regards,
Mehrpad

Hi Steffan,

    I have a question about how to acquire the stop channel: 

    Process:   Configure the Write Shift Register with 00010001b to achieve 4-channel cascading, then after a trigger, set A3-A0 to 1101, sclk keeps 0.

    Result:   the WSROUT pin keeps 0, the SROUT pin has no clock pulse as written in datasheet, but keeps always 1 or 0. It can be seen the stop channel is channel 0 or channel 1, but no situation to represtent channel 3 or channel 4. And if set sclk with 8 pulses, the  WSROUT and SROUT both keep 0.

    What should I pay attention to? Looking forward to your reply.

Jiaolong 

Hello, 

I made a modified version drs_exam_multi.cpp, but ran into an issue when running.  When I ran it, it only found the two boards with lower serial numbers (2781 and 2879) and complained that the others (2880 and 2881) were not v4. Would there be a simple workaround for this type of thing? Also, would I be able to use the .dat format to keep the file sizes down. 

If not, I am curious if there is a way I can at least set a default configuration for the drsosc program. It seems the drsosc.cfg is written when drsosc starts? Does it load the configuration from somewhere else? It would be very helpful to keep the same settings between runs, in particular the trigger delays, levels, trigger mode, and voltage offsets. Maybe I can even do this with just a few of the CLI commands? I know this is for experts only, but I think I would just need a few commands (setTrig, setTrigMode,  setTrigDelay, that sort of thing) if they do exist. I would check the help now, but I'm running, and I'm pretty sure I saw some for trigger settings. 

Anyhow, any help is appreciated in creating a more repeatable and automated data acquisition. Thanks!

Dear experts,

I would like to use the DRS4 evaluation board for actual physics experiment.

I made a CUI script based on the drs_exam, https://github.com/mzks/drs4_tools/blob/main/build/source/drscmd.cpp.

In this framework, how can we obtain DAQ livetime (or deadtime)?

Has some function already provided to evaluate them from firmware?

Best regards,

Keita

Thank you very much for your response.
Excuse me for my very stupid confirmation.
If I take N events finally and the hardware scaler value is M, the livetime is realtime*(N/M). Is this correct

Hi Stefan,

I have two problems regarding using the drs_exam file with external trigger:

1- I connected a 200Khz signal with 20ns rising edge, 50 ohm load, and 27% duty cycle as an external trigger. The output of the drs_exam file starts from 0 to 200ns. Since I use an external trigger, I think it should be starting from 0 to 5ns and then again starting from 0. Could you please tell me where the problem is?

2- How is it possible to change from 1024 to 2048 bins in the drs_exam example?

You can find my code in the attachment.

Best regards,
Mehrpad

Hello,

I recently acquired 4 DRS4 boards and I wanted to ask if it was possible to trigger them independently from the same computer.

I know that you can daisy-chain boards and trigger them all at the same time, but in my case, each of my boards record independent events, so I want them to trigger when trigger conditions are met in each board. I currently use the provided DRSOSC software, that can trigger on only the board that is being displayed at that moment. I tried opening several instances of DRSOSC to associate each to each board, but that is not possible since the second instance already does not find the boards. I wonder if there is a way of triggering from each board independently without having to use four computers.

Thank you,

Javier.

A related question is: if the 4 boards are triggering at max rate (500Hz), would the total data throughtput (of the four boards together) be 2GHz (500Hz x 4)? Or is the limitation on the readout, rather than the triggering?

Hi everyone,

I'm still looking through the forum for an answer to this question, but thought I'd go ahead and post anyway just in case it hasn't been answered yet. If it has I can take this post down.

I have a V3 board, and as far as I can tell only channel 2 gives an output. If I enable other channels using the DRS Oscilloscope software, they do show static but will not show a signal if I connect one to them (e.g. a series of subsequent square waves). A technician and I took the board out and tested all the components leading up to the microcontrollers for each channel, and everything seemed to be working fine. I thought maybe it was configured to only have one channel read an output, but I looked through the Config panel in the software and nothing seemed to indicate that.

I am a novice, and maybe I'm missing something that I didn't see in the manual. I can post screenshots if needed!

Thank you for your help!

Dear Sir or Madam,

      Good morning，I am using drs4 chip, and the measured fDTAP == 1/350ns, that is, fDOMINO == 1 / 350ns * 2048 == 5.8GHz.

     I have three questions:

                              1. Is fDOMINO determined by the chip itself?

                              2. C1, C2 and R2 are TBD. I don't know how many to choose. Is there an algorithm?

                              3."Configure Write Shift Register to contain all 1's"，What, pray, is the meaning of “1's"?

                                                                                                                                                          Truely yours.

Am I right in thinking that inputting 1 to DMODE (Bit0) in the configuration register will connect the 1024th cell to the 1st cell?

Also, let's assume that after sampling 1024 cells on channel 0, 200 cells are sampled in the second week.
Does the readout of 1024 cells start from cell 0?
Or does it start from the 200th cell?

Am I correct in assuming that drsosc and drscl are functionally equivalent regarding collecting data? We want to run the DRS4-EB for a predefined amount of time. However, the DRS4 scope application seems only to run for a predefined set of measurements. Have I got that right? Is there some reason to avoid running the DRS4-EB for a predefined amount of time that I should be aware of?

I am using the `drscl` app. My prior experience is practically zero, sorry if this is a very naive question. When I read using `read 0 1` (channel 0, with calibration) I get this:

```
Calibration not valid for board #2946
  10    3    7    4   10    8   14    5    5    9    3    4    9    8    9    4
   3    3   12    5    5   13    3    8    1    5    0    4    8    6    6    3
...etc...
```

Why does it says that the calibration is not valid? How am I supposed to go from integers to volts?

If I run the `info` command I get this:

```
==============================
Mezz. Board index:    0
DRS type:             DRS4
Board type:           9
Serial number:        2946
Firmware revision:    30000
Temperature:          43.4 C
Input range:          -0.5V...0.5V
Calibrated range:     -0.5V...0.5V
Calibrated frequency: 0.000 GHz
Status reg.:          0000009A
Control reg.:         00000000
  DMODE circular
Trigger bus:          00000000
Frequency:            1.007 GHz
```

Hi. I'm trying to evaluate livetime of the evaluation board with the hardware scaler. I'm facing a strange issue.

I took the rate with the function, DRS->GetScaler(int channel).
I guess that channels 0--3 mean the rate for the channel, and channel 4 means the counter of the trigger.
I took the 1,000 pulses generated by a pulse generator with 50 Hz.
The scaler values are ~ 39.83, not 50.
The timestamp difference between the initial event and the final event is 19.98 seconds.
1000/19.98 ~ 50, thus, the evaluation board took the pulses with enough livetime.

Can we believe the scaler value for the livetime evaluation?

Thank you very much for your explanation.

I would like to show you a pulse example ('black line is the threshold).

Still, pulse generator rate and DRS4 rate are a bit different more than 10 Hz.

I am using the V5 board at a fixed sampling frequency. With the `drsosc` app I have executed the time calibration at 5 GS/s (actually 5.12 GS/s). This is how my setup looks like in the app:

Now I want to replicate this using the C++ API (not the positive width measurement shown, the signal sampling only). I am seting the sampling frequency to 5 GS/s, as I do in the `drsosc` app. Then I get the time information using the `DRSBoard::GetTime(unsigned int chipIndex, int channelIndex, int tc, float *time)` function (which I don't find defined either in `DRS.h` or `DRS.cpp` but somehow it works). How can I know if these times that I get here are being corrected with the time calibration? If so, should I expect the time resolution to be < 3 ps? Are these 3 ps accumulative, such that in the end I end up having a contribution from the evaluation board of 3 ps × 5 Gs/s × 100 ns where 100 ns is the time difference between my two pulses? (This does not seem to be the case because if so I would expect the jitter to be ~ 1 ns, and we see that the "Pos Width" measurement is ~ 0.1 ns std.)

Why am I asking? I want to measure the jitter between the two falling edges. This cannot be done easily with the `drsosc` app I think, so I am acquiring the data and doing this offline. I have done this measurement in the past using a LeCroy WaveRunner oscilloscope with 20 GS/s and 4 GHz bandwidth (offline, same code) and I have seen it vary from ~5 ps → 30 ps when I vary a voltage that I can control. Now if I calculate this time fluctuation using the data acquired with the V5 evaluation board I get a value ~100 ps and independent of this voltage, which leads me to conclude that the limiting factor is being the evaluation board itself. So now I am wondering if I have reached its limit, or if there is some setting that can still improve this result.

Thanks!