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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.