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    User name V. Sulkosky

    Log entry time 01:19:19 on February 26, 2011

    Entry number 348698

    This entry is a followup to: 348673

    keyword=Re:DAQ Deadtime Issue so far unresolved

    The deadtime is still not understood.  The online deadtime GUI and scalers
    indicate that with a 630 Hz rate on T7, we should be taking about 500+ Hz
    with a deadtime of about 15-16%.  Even the run control GUI indicates this
    rate.  However, both the number of accepted events and the end-of-run 
    files indicate that the deadtime is about 31% or twice what the online
    monitor shows.
    
    Alexandre is going to look at the data files themselves and continue 
    looking into the issue, while beam is still unavailable.
    
    btw, yesterday morning (Feb. 25th) and in the afternoon the deadtime from
    the end-of-run file appeared to some level reasonable.  With 150 Hz of T6
    from BB wire chambers, the deadtime was about 7%.  Perhaps a bit high
    though.  The deadtime seemed to start having a large discrepancy around 6 pm.
    


    A copy of this log entry has been emailed to: kalyan,doug,danez,rom,yez