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    User name paschke

    Log entry time 15:37:20 on June21,2004

    Entry number 126528

    keyword=How to Fix bpm12 when it goes bad

    
    Sometimes bpm12 readback goes bad. This happens most often when beam 
    is coming on and off, or when we are changing current a lot.  This
    has been identified as a minor (and transitory) FastFeedback 
    misconfiguration, which can be fixed easily.
    
    When bpm12 starts to look funny (either saturating in our ADC readout,
    or having an absurdly small width) call MCC and utter the following
    incantation:
    
    "There is a DAC failure on the Hall A FastFeedback. Please do a gain search." 
    
    The ops can fix the problem right away, very easily.  They usually 
    catch this error themselves and solve the problem, but occasionally it
    escapes their attention.  Now that we know the magic words, we can
    remind them.