FA125 Data Format Sep 22, 2015

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Location and Time

Room: CC L207

Time: 2pm.

Remote Connection

You can connect using BlueJeans using the meeting number 589 693 655 .       (Click "Expand" to the right for more details -->):

(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: (bjn.vc) and enter the meeting ID: 589693655.
  2. To join via a Web Browser, go to the page [1] https://bluejeans.com/589693655.
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Specific instructions for connecting via polycom:

  • Turn polycom on if necessary
  • With the polycom, place a call at
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  • Previous meeting (Sept 8, 2015)
  • FADC125 Firmware status
  • Driver library status
  • Format doc v7 errata:
    • (1) In config parameter restrictions, need to change NW > ((2^P1) + 6)) to NW > ((2^P1) + NE))
    • (2) start hit search from NPED+PG, not NPED, to prevent looking back too far with local pedestal calculation ending with threshold crossing X-PG-NPED2
  • Testing plans
  • Collaboration meeting

Useful Info


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

  • FADC125 Firmware status - this is in good shape and Cody has been working with Sergey looking at rates. He plans to test in simulation to see what the limiting rates are. The front end buffer contains up to 4 events, he will look to see if this can be increased. (?)
  • Driver library status - Cody will give Bryan the details he needs to update the driver after he (Cody) has finished testing and is reasonably sure that there are no more bugs.
  • Format doc v7 errata:
    • (1) In config parameter restrictions, need to change NW > ((2^P1) + 6)) to NW > ((2^P1) + NE)) - this affects the library code only
    • (2) we need to change the firmware (and documentation) to start the hit search from NP+PG, not NP, to prevent looking back past the start of the data buffer when calculating local pedestal which ends with sample X-PG-NP2 where X=threshold crossing. This can go below 0 if NP2=NP and X<PG. Starting the hit search at NP+PG ensures that this will not happen. (See the diagram above).
  • Testing plans - Naomi has still to test more parameter variations and all the other modes - so far she has been looking only at cdc_long. Cody thinks the full-crate tests should take a few days and after that we should put the firmware onto all the FDC/CDC crates and use it with cosmics.
  • Collaboration meeting - Naomi has to give an update including a schedule. We hope to be using the firmware with cosmics before the meeting starts.
  • The firmware to-do list contains:
    1. fix the problem where a reset causes the front end to hang (is this the same as the first-event-after-reboot timeout bug?)
    2. fix the parameter out of range bug in the timing algorithm
    3. increase the field width for TH
    4. add fdc_amp_long, in a separate version for diagnostics only, if necessary
    5. change the hit search to start with sample NP+PG
    6. and test in simulation and then for real
  • Naomi's to-do list includes:
    1. update the format doc, text and diagrams, following erratum 2 above
    2. keep testing, including other modes
    3. dig up collection of nasty pulses and send the signal data to Cody for testing in simulation