Dear Mr. S. Ritt

       i am Ms. student , am working with your DRS4 board to calculate the time of flight of the cosmic particle which passes trough  the hodoscope . i see the signals at scope , which is negative (i don't want to take positive side of the signal).

       i am using your drs_exap.cpp file to  take the data, i set the analog trigger source , threshold level is negative, like this(b->SetTriggerLevel(-30, true) ); but the exam file also registers the positive side of signal (i think  that is spike or internal reflection), is it possible to eliminate this spike? Also i want to register  the data just after the threshold value, but that is always triggered, i think that caused from the mode. Is it possible to set the trigger mode to normal in exam file?,and  how can i do that?

Best regards.

Sincerely,

 Ali YILMAZ (ali.yilmaz@roma1.infn.it)

Working with the DRS evaluation board we noticed some funny behavior: See attatchment 1. In about 1% of scope traces we see the first and last bin take on a value substantially different from the baseline, note the small spikes on the end of the traces. These spikes occur across all channels and either appear in all channels or in none. Attachment two shows what several thousand scope traces look like. You can clearly see that some of the traces are offset from the normal base line. Has anyone observed this behavior before? Any ideas?

see https://muon.npl.washington.edu/elog/g2/Detectors/550 for full discussion. 

 Thanks for the quick reply. Our quick fix was to do just that. 

Hello,

I have a question about using the write config register to enable/disable sampling on the fly.  I am looking to instrument an experiment at EPFL where multiple short events need to be captured during a 20us period followed by an 80us quiet period during which we could read out the chip.  Would it be possible to start an acquisition with all channels seeing the same signal and the write config register set to 111111111 and then shift a zero into the write config reg after each event is detected to freeze the channels in time one-by-one?  In this way we could measure up to 8 different events during the active period and then read them all out together during the quiet period.  I have read the posts about the simultaneous read-write mode and the issue with waveforms stopping at cell 767.  not knowing the exact details of what causes this issue I wonder if it would effect this sort of operation?  Also, I would like to know if dwrite must be de-asserted while the write config register is being updated or if it could be done while the sampling is active?  The latter would obviously be preferable as we would not incur any dead-time during the active period.

Thanks in advance for the information,

Benjamin LeGeyt

If I may trouble you for a little more information, the critical point then is that there should not be any zeroes in the write config register while the sampling is active?  In case it was unclear I would only be reading out once sampling was stopped (dwrite = 0).  

As for the readout, I know that I would have to read out all 1024 samples each time, and keep track of where each channel stopped in the FPGA.  I would never know the exact cell where sampling stopped but I hoped that if I discard some number of cells on each side of the expected stopping point that I would be OK.  

Thanks again

Hi! Stefan:

  when I change a new computer(win7,64bit),I meet a problem that the drscl app cannot found the board! It shows"USB successfully scanned,but no boards found",but the drsosc runs well . when I connect to other win7*64bits computer,only one of them runs property! Is there any driver else I need to install? 

Thank you!

Chen

Hi! Jim:

  It seems that I meet the same question with you ,and I am confused ,have you find out the reason about this problem?Or can you tell me how you deal with it?

Thank you very much!

chen

I have tried about 4 computers,only one worked fine.I truly want to know how others get this fixed,can you get in touch with them?

Hi,Stefan:

  recently,whtn I study the drs.cpp code ,I found that  the buffer[1] is char but the addr and the base_addr are all unsigned int,isn't there any problem that the addr may be cut off to 8 bits? Also ,I found that the data fpga recieved from the usb is 16 bits,so how can fpga get the true 32bits address from the PC.

Hi Stefan:

  I'm still confused that althought the 8 bits buffer is enough,the FPGA receive the command through the uc_data_i register which is 16 bits wides.As we can see in the firmware, the locbus_addr is 32 bits wides. Does it means the locbus_addr[31:8] are always '0' because the address in buffer is only 8 bits. Does it means the usrbus_status_sel and usrbus_ram_sel are also '0' all the time .

thanks!

chen

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!

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.

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

Is DRS4 suitable for use with Silicon surface barrier detectors?

Hi

I have just installed DRS4, but when I try to view it from the USB it don't work. Why?

  [  .../home  $] lsusb -d 04b4:1175 -v

Bus 002 Device 008: ID 04b4:1175 Cypress Semiconductor Corp.
Couldn't open device, some information will be missing
Device Descriptor:

Hi,

    We are using drs4 board, but oscilloscope app will somehow stop to work if we config trigger into "or and", When I look into the drs4 firmware file drs4_eval3_app.vhd, I couldn't find the trigger_config value assignment which is mentioned at(#7 offset 0x1E from 31 downto 16) in manual_version 4.

could you help me find this trigger_config access point? Or is there any drs4_eval4_app.vhd missing in the source files?

thanks

Hongwei

 Ah, great, that helps, Thank you!

Hongwei

 By the way, will there be a drs4_eval4.vhd as well?

 Thanks. have a good day

I m trying to measure lifetime in our lab and I intend to take
measurement with DRS4 at that point I have a little bit confused about
DRS4 time range.In My system I opened 10 us gate but after triggering
DRS4 measure nearly 1.2 us. Because of this I want to extend DRS4 time range that
measurement range from 1.2us to 10 us.