• Main INDEX
  • Monthly INDEX
  • PREV
  • NEXT
    Make New Entry, Make Followup Entry

    User name R. Michaels

    Log entry time 04:15:41 on August30,2009

    Entry number 286993

    This entry is a followup to: 286945

    keyword=re: ADC18 in ROC26, 4th slot

    In run 11735 the anomoly occurs in the peak measurement. Some values
    are saturated, but it's even worse than that because there is a
    discontinuity near event 5000. FWIW, several other runs I spot
    checked were clean.

    One strange thing about this ADC is that the csr register is always
    1 for all channels and all runs. Normally it should be 9.
    (9 = 8 + 1, where 8 means power-on and 1 means event ready.)
    This csr oddity is occurs only for this ADC.

    We may consider replacing this ADC. (I'm considering putting
    the 16-bit ADCs in for the physics detectors to be safe.
    A follow-up will be posted shortly.)

    Some code to diagnose ADC18: ~apar/adc18_ana. See README.
    I scan for a host of possible glitches, but I'm not finished
    with it yet.