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    User name R. Michaels

    Log entry time 23:44:02 on October20,2008

    Entry number 244197

    Followups:

    keyword=attempts to fix roc4

    Below is what I did to try to fix roc4 readout.
    The present status is that it reads fast (76 usec deadtime)
    but only with a hack (see below). I worry there may
    be a serious hardware problem with this crate.

    The hack: each event, first read, then ignore, the 1875 which
    is presently in slot 18 (only). It would be better to read
    then clear; will try that tomorrow.

    Sequence of tests:

    datascan indicated the 1875 in slot 25 was reporting anomolously
    even if it was not in the list of modules. What I mean by
    "anomolously" is that the function fb_frcm_1 indicates that
    slot has a hit, and furthermore the function takes a geological
    timescale to return (ca 140 msec !!).

    Physically removed the TDC in slot 25 (note, I tried to recable
    things but this should be checked).

    Next got anom. reporting from the (different) 1875 in slot 18.

    I decided to replace the scaler 1151 in the SFI since it showed
    a bus error. I put in a CAEN V260 to grant the bus. Did not help.

    At present the DAQ runs fast with the aforementioned hack but
    on rare occasions all 3 modules report anomolously.

    Fastbus test code revealed no problems with the bus or modules.