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    User name Kalyan

    Log entry time 20:35:46 on February 06, 2009

    Entry number 259350

    Followups:

    keyword=Dead time study for buffered and unbuffered mode on the BigBite DAQ

    Dead time study for the buffered vs unbuffered mode is done for the BigBite DAQ. Here are the results.

    This test was done by reducing the discriminator thresholds on the BB to get high rates. T1 ~ 47Khz ; T2 ~ 2.6Khz ; T6 ~ 190Khz

    Unbuffered Mode:
    --------------------------------------------------------
    Run #  | Input rate(KHz) | L1A rate(KHz)  |  DT(%) from datamon | 
    --------------------------------------------------------
    1046          0.6            0.55            4    (8%)
    1045          1.2            1.0             10   (17%)
    1044          1.8            1.4             13  (23%)
    1043          2.5            1.8             18  (28%)
    --------------------------------------------------------
    

    Buffered Mode: ----------------------------------------------------------- Run # | Input rate(KHz) | L1A rate(KHz) | DT(%) from datamon | ----------------------------------------------------------- 1047 0.6 0.6 0 1048 1.2 1.2 0 1049 1.8 1.75 0 effectively ~3% 1042 2.5 2.2 0 " ~4% 1050 3.0 2.8 0 " ~8% 1051 6.0 4.0 8 " ~33% --------------------------------------------------------

    The DT in brackets is what we expect roughly from the L1A rate and input rate. but due to correlations in the triggers the datamon was showing less that what we expect(?)

    I guess this study really have to be done with beam to get better idea. In any case in buffered mode we can at least take 3 KHz, I think.



    A copy of this log entry has been emailed to: brads,rom,moffit