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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.