Difference between revisions of "FADC Data Format January 13, 2015"

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(Created page with "= Location and Time = '''Room:''' CC F228?? '''Time:''' 2pm. = Remote Connection = (if problems, call phone in conference room: 757-269-6460 might not be the correct number) #...")
 
m (Text replacement - "http://argus.phys.uregina.ca/cgi-bin/private" to "https://halldweb.jlab.org/doc-private")
 
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= Agenda =
 
= Agenda =
−
* [[FADC_Data_Format_November_25,_2014|Previous meeting (Nov 25, 2014)]]
+
* [[FADC_Data_Format_December_9,_2014|Previous meeting (Dec 9, 2014)]]
 
* Status of FADC125 Firmware
 
* Status of FADC125 Firmware
  
  
 
== Useful Links ==
 
== Useful Links ==
−
* [http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=2274 fADC125 Data Format Specification Document]
+
* [https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=2274 fADC125 Data Format Specification Document]
 
* [[:File:FADC125_dataformat_250_modes.docx|Data format for 250 modes on fADC125 from Cody, Aug 15 2014]]
 
* [[:File:FADC125_dataformat_250_modes.docx|Data format for 250 modes on fADC125 from Cody, Aug 15 2014]]
 
* [[:File:FADC250_modes_2.docx|FA250 modes 2 from Ed and Hai, Feb 18 2014]]
 
* [[:File:FADC250_modes_2.docx|FA250 modes 2 from Ed and Hai, Feb 18 2014]]
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=Minutes=
 
=Minutes=
−
Present: Naomi (CMU), Cody, Beni, Lubomir, Mike (JLab)
+
Present: Naomi (CMU), Mike, Cody, Beni, Lubomir, Sergey (JLab)
  
−
#Cody identified a number of ways to improve the peak search, with the 250 firmware it is looking for a simple threshold crossing but for the fa125 if we can increase the chance of having identified a genuine peak (not a noise) then we will run into fewer problems later on
+
#New FADCs - Cody has tested all but 1 (which is still in transit) of the 25 new FA125s and found problems with only 2 of them.
−
##a noise bump on the leading edge of a larger peak - change the search to look for 3 consecutive decreasing (or maybe constant) samples after the peak sample. Constant samples at a peak would most likely occur with saturation.  
+
#Bad FADCs in use - Cody would like to replace these with the new good modules, asked for a list of bad modules.  He has [https://halldweb.jlab.org/wiki/index.php/CDC_bad_channels Naomi's list of bad channels] from run 1286 but it would be useful if someone could run a pulser test over all the modules again.
−
##the peak should have a minimum number of samples above threshold, Naomi and Lubomir will provide default values (which can be different) for the CDC and FDC. This should eliminate some noise peaks. 
+
#Early hits - Cody will look at the channels for HVB C8 (roc 28, slot 15, channels 48-71) to investigate why they are 40ns earlier than the rest. ([https://halldweb.jlab.org/wiki/index.php/CDC_run_2016_drift_time_fits more details here])
−
#After finding a first peak, the 250 algorithm starts the search for the next peak NSA samples later, and the next peak is found when the adc values increase and cross the threshold.  Lubomir said it is not necessary to wait NSA samples for the FDC (the CDC will only be using the first peak), and the data do not need to cross the threshold again, he wants to record the next maximum, the data will probably not fall below the threshold between the maxima. The peak data will be returned in the order found, as with the 250 firmware.
+
#Naomi is adding some error-prevention conditions to the new timing module, it returns a rough time (initial hit threshold minus a  registered configurable constant) if any of these are met.  These include - adc value of 0 or >4095, pedestal above configurable value (suggested 511) and will need an extra bit sent to the module + another register value.
−
#As the first part of the integral is calculated in the timing code, there should not be any data formats where the integral is calculated and not the time. We agreed upon this.  We do not wish to record integrals without time data.
+
#Cody is not confident that he will have the new firmware completed and tested by April and would prefer to fix some problems with the old FA250 firmware first. He will have an estimate of how long that will take at the next meeting. Beni said the run goal is higher rates and the drift chambers cannot use mode 7. The problems to fix are:
−
#Naomi found some instances where the upsampled data were very dissimilar to the samples due to discontinuities in the signal due to faulty bits in the fadc readout.  She needs to alter the timing code to allow for this (ie stop).
+
##remove the extra header and trailer words in the data (one set of these for every 6 channels)  
−
#The max number of samples that can be read out using the present firmware is 511.
+
##triggers too close together cause overwriting of data.

Latest revision as of 16:58, 24 February 2017

Location and Time

Room: CC F228??

Time: 2pm.

Remote Connection

(if problems, call phone in conference room: 757-269-6460 might not be the correct number)

  1. To join via Polycom room system go to the IP Address: 199.48.152.152 (bjn.vc) and enter the meeting ID: 589693655.
  2. To join via a Web Browser, go to the page [1] https://bluejeans.com/589693655.
  3. To join via phone, use one of the following numbers and the Conference ID: 589693655
    • US or Canada: +1 408 740 7256 or
    • US or Canada: +1 888 240 2560

More information on connecting to bluejeans is here

Specific instructions for connecting via polycom:

  • Turn polycom on if necessary
  • With the polycom, place a call at 199.48.152.152
  • Press # to enable the polycom keypad, then enter the meeting id: 589693655 and #
  • You may have to unmute the microphone: #*4
  • Turn the computer on if needed

Agenda


Useful Links

Minutes

Present: Naomi (CMU), Mike, Cody, Beni, Lubomir, Sergey (JLab)

  1. New FADCs - Cody has tested all but 1 (which is still in transit) of the 25 new FA125s and found problems with only 2 of them.
  2. Bad FADCs in use - Cody would like to replace these with the new good modules, asked for a list of bad modules. He has Naomi's list of bad channels from run 1286 but it would be useful if someone could run a pulser test over all the modules again.
  3. Early hits - Cody will look at the channels for HVB C8 (roc 28, slot 15, channels 48-71) to investigate why they are 40ns earlier than the rest. (more details here)
  4. Naomi is adding some error-prevention conditions to the new timing module, it returns a rough time (initial hit threshold minus a registered configurable constant) if any of these are met. These include - adc value of 0 or >4095, pedestal above configurable value (suggested 511) and will need an extra bit sent to the module + another register value.
  5. Cody is not confident that he will have the new firmware completed and tested by April and would prefer to fix some problems with the old FA250 firmware first. He will have an estimate of how long that will take at the next meeting. Beni said the run goal is higher rates and the drift chambers cannot use mode 7. The problems to fix are:
    1. remove the extra header and trailer words in the data (one set of these for every 6 channels)
    2. triggers too close together cause overwriting of data.
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