FADC Data Format December 9, 2014

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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), Cody, Beni, Lubomir, Mike (JLab)

  1. 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
    1. 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.
    2. 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.
  2. 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.
  3. 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.
  4. 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).
  5. The max number of samples that can be read out using the present firmware is 511.
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