No, I can't think of anything else. There is no intermediate addressing stage. The only thing which sometimes happens is that the QFN76 package is not soldered correctly. If you don't have this under control, some pins might have a bad contact. You can check this by touching with a oscilloscope probe not the PCB pads but really the pins from the side, which is a bit tricky.

Stefan

Hello,

I am writing a VHDL code to drive a DRS4 chip.

In order to configure the DRS4 chip, I have to set the "Config Register" and the "Write Shift Register" then ... (I do not plan to use simultaneous WR and R so I guess the Write Config Reg. is not needed)

My question is :

When do we have to perform a "Read Shift Register Initialization" ?

Every time before a full read-out, or juste once after a DRS4 reset ?

Further more, is this initialization needed for the ROI mode ?

And at last do the level of the DENABLE and DWRITE signals matter for the "Read Shift Register Initialization" ?

(To sum up : what is the purpose of the Read Shift Register and how does it work ?)

Cordially,

G.Blanchard.

There are two readout modes "Full Readout Mode" and  "ROI mode". 

In the Full Readout Mode, the Read Shift Register has to be initialized before the first readout by applying the sequence shown in Figure 11 in the data sheet. This clears the full shift register and sets the first cell to "1". In principle in the following events one applies each time 1024 clocks. Since the shift register is circula, the single "1" rotates through the shift register and is at the same position after 1024 clocks. So in principle the register does not have to be re-initialized. To be hones I have never tried this myself, so I'm not completely sure if that works.

In the ROI mode, you initialize the Read Shift Register by a single RSRLOAD pulse as shown in Figure 15. Since the inverter chain stops at different positions in each event, this pulse has to be applied before each event. The SROUT bits will then tell you where the inverter chain has been stopped.

Most people I know of use the ROI mode, since the initialization is much simpler (just a single pulse).

Best regards,

Stefan

Dear experts,

I would like to use DRS4 evaluation board as DAQ system for small, table-top experiment.

I need waveforms capture as binary file on some trigger based on command line without GUI.

I found `drscl` tool in official software, but it require interactive command. I'd rather use static macro or so on to control DAQ as same behaviour in each time.

I guess, experts are thinking users should develop DAQ code by themselves for their experiment specifically, but my request is very common so someone has already developed these tool.

Best regards,

Keita

There is an example program in the distribution under software/drscl/drs_exam.cpp which is a stand-alone program to do what you need. It uses the C library coming with the distribution. It configureres the board, defines a trigger, and then writes a few waveforms into a file. You can use it as a starting point for your development. If you need any other language, you have to develop bindings to the C library.

Stefan

Thank you very much. That is what I wanted.

Hi, I have a DRS4 v5 evaluation board and I have a novice question about the oscilliscop application. When I connect it to a photo-detector (silicon photo-multiplier to be exact), the signal appears only on one half of the screen, and I cannot change it to be full screen, and pulse to be centered. I tried changing delay time and played around with the settings of the applicaton but no success. I'd apprecite if someone help me on this, probably very simple, problem.

There is a horizontal position slider in the "Horizontal" box on the right side below the trigger delay. Use it.

I am trying to use 4 evaluation boards with a powered USB hub (since eventually, I will have to do this on a laptop).  It seems like destroying the DRS object is insufficent to properly close the boards when on the hub (i.e. I get usb read errors next time I run my program). When all the boards are plugged into the computer, all is fine.  This is on Linux using libusb1. My guess is something about resetting the port doesn't work properly (but maybe that's this particular hub's fault?).  Has anyone else experienced a similar issue. If not, can someone recommend a hub that is known to work?

Hi,

I`m trying to calibrate my DRS4 evoluation board to an input range of 0-1V but it doesn`t work.

1) First I tried to calibrate it with the drsosc (version 5.0.3) Software. The -0.5V - 0.5V calibration works, but during the 0 - 1V calibration the Software crashes.

2) I also tried to calibrate the input range with a C++ DAQ Package (based on drs_exam). Here the code of the calibration:

    ....

    b->SetInputRange(0.) (Center at 0 V )

    b->CalibrateVolt(NULL);

   ....

   Calibration Works

   ....

   b->SetInputRange(0.5) (Center at 0.5 V )

   b->CalibrateVolt(NULL);

  ....

   Results in: Found 4096 stuck pixels on this board.

Did I do a mistake or is this a normal behaviour of the board? Also the board often crashes and I get a magic number 0000 after restarting the DAQ. Then the board needs to be restarted via pulling the plug. ( I ensured that I terminate the USB connection before I close the program with "delete drs"). Is there a possibility to avoid this error?

My OS: Ubuntu 14.04 LTS.

Ciao,

Julien

1) I tried to cablirate a V5 board with drsosc 5.0.3 and it just worked fine for me. No idea what went wrong in your case.

2) The "found 4096 stuck pixels on this board" can be safely ignored. It comes from the fact that the standard evaluation board has four cannels unconnected (the DRS4 chip has 8 channels, four are connected to in the evaluation board and four are unconnected). So the software sees wrong values on four channels because they are unconnected and thinks something is wrong. Unfortunately the software cannot determine if the channels are connected or not. So just ignore it.

3) I heard several people having to reset their boards under Linux in a similar way than you. This is probalby due to some instability in the USB part of the linux kernel, since the problem does not occur on other systems (Windows, Mac OSX). So I cannot do anything from the software side.

/Stefan

I also use Ubuntu 14.04 LTS and for my V3 borad I have to use drsosc 4.x or ealier to perform the calibration.

Sure, for a V3 board you need a pre-V5 software, but I assumed Julien had a V5 board. 

Dear Stefan

I am trying to use the DRS4 eval board on a Windows7 machine. Unfortunately I get an error message saying "No DRS 
board found". But I can see the DRS board in the device manager with the proper driver loaded. Is there any known 
problem with win7?

I am using windows7 professional (SP1) with the drs software 5.0.1.

Cheers,
Roman

PS: Everything is working on my mac. But not under windows7.

> 
> Dear Stefan
> 
> I am trying to use the DRS4 eval board on a Windows7 machine. Unfortunately I get an error message saying "No DRS 
> board found". But I can see the DRS board in the device manager with the proper driver loaded. Is there any known 
> problem with win7?
> 
> I am using windows7 professional (SP1) with the drs software 5.0.1.
> 
> Cheers,
> Roman
> 
> PS: Everything is working on my mac. But not under windows7.

Hi Roman,

please read section 2.3. (page 13)  from the Evaluation Board manual: http://www.psi.ch/drs/DocumentationEN/manual_rev50.pdf

You have to update the USB driver in your Computer Management.

Cheers,
Stefan 

Hello All,

I am currently trying to figure out how to properly characterize the dead time of the DRS4 board. My most recent experiment to try and answer this question involved using an external trigger that can range from 1Hz to 2MHz. I fed this trigger into the DRS4 and collected 1000 samples with no input to any channels. I repeated this across the range of my external trigger by a factor of ten [10Hz, 100Hz, 1kHz...etc]. After I had saved these runs in XML format, I looked at the difference between timestamps on the events. Attached are my findings. Can someone offer an explanation for the periodic peaks? I am new to the DRS4 and don't really understand how it works. My guess is that there is a buffer that has to be emptied every so often, but if so, the buffer emptying time varies with the frequency of the trigger. I would ideally like to be able to know the relation of the dead time to a particular setting I change on the DRS4 such as locking the sampling speed or changing external trigger frequency. 

Best,

Steven

XML is very slow to write, and you are probably limited by that. Switch to binary mode, which is much faster. You will see in the end a maximum rate of ~500 Hz, and thus a dead time of 2ms, independent of the sampling speed. Note that you have only an evaluation board, which is optimized for ease of use. If you develop your own electronics, and do optimized readout, you can bring the deadtime down to 30ns x number of samples + 2us, or 32us if you read 1024 values from one channel.

Stefan

That is extremely helpful! Many thanks. One more question; If I were to take inputs from 2 channels at once, would that scale the dead time to 64us using your example? 

Steven

For applications which are critical on the dead time, one typically uses one ADC per DRS4 channel, and thus the dead time stays at 32us. If you multiplex two DRS4 channels into one ADC channel, then it goes to 32us.

Stefan

Hello,

We are using DRS4 Rev.2.0 board.

We want to measure number of pulses generated  by charge particle detector. These negative going analog pulses are very fast having rise time about 2nS.

We want keep threshold level to -20mV. We expected pulse rate to be about 100 to 200 Hz.

I need help to implement this in  current DRS board with  dead time free operation.