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    User name tchang, Ed

    Log entry time 02:41:29 on February22,2002

    Entry number 3501

    keyword=ROC4 problem persists

    ROC4 problems:
    starting from 2/20/2 we had encountered ROC4 problems. The symptom appears to be that ROC4 busy won't drop. After start run, the ADC modules seems to get the gate, but the yellow slave LED doesn't flash. The crate busy will then asserted. After a few seconds the gate green LED will also disappear. Only the RDY and USV lights
    on the SFI flashing. Trigger supervisor gets the triggers normally and sending out
    L1A without stopping. The handshake between TS and the ROC seems OK.

    We did the following:
    -- moved the SFI in ROC4 to ROC3, ROC3 still works.
    -- moved the SFI in ROC3 to ROC4, it gives error "SFI arbitration timeout" during
    prestart of ROC4. (the sfi from roc3 is restored after the test)
    -- original SFI in ROC4: no error message except the strange behavior described
    above.
    -- Get a "fixed" SFI from the electronic pool -- doesn't help.
    -- replaced geographical control card and time arbitration card in ROC4 (we
    borrowed these two cards from the Right-Arm) -- bad symptoms persists,
    doesn't help.
    -- We found no ADC gate and TDC stop signals send to the fastbus gate
    distribution card. Both signals come out of L1A, after fanout the ADC gate goes
    to the CAMAC delay module but no output signal from the CAMAC delay. And
    the TDc stop goes to a NIM discriminator and also no output signal from that
    disc units!

    It seems many different problems come up all at the same time. We'll keep
    working on this in the day shift.