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User name R. Michaels
Log entry time 04:50:56 on August30,2009
Entry number 287001
keyword=ADC18 Test Crate Study (Part II)
Before deploying the new ADC18 code, I wanted to explore what
would happen if the DAQ crashed.
The ADC18 can get into a "funky state" which can only be
cleared by power-cycling. This can be avoided, however, with
a VME check task that clears the ADC rapidly if the DAQ
crashes. Also, a loud warning is issued whenever the ADCs
get into this state.
As it was complex, I refer interested readers to the file: ~apar/dev_bob/funky_state.txt
Considering all the problems we have I am presently nervous
about running HAPPEX physics detectors with the 18-ADCs.
One possibility is to swap to 16-bit ADCs for these detectors
and leave the 18-bit for Lumi and Cavities. We can also add
one 18-bit ADC in the CH crate for an alternative BCM.
On the other hand, maybe we replace the suspectedly bad
ADC in ROC26/4th-slot, deploy the new software, and use
the improved diagnostic code to watch things.
It's up to the spokespersons to decide. I may call in at
the 3pm Sunday meeting if someone sets up the phone line.