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    User name V. Sulkosky

    Log entry time 20:57:40 on May 06, 2009

    Entry number 271292

    This entry is a followup to: 271273

    keyword=re: roc8 busy

    Bo and I found a spare TwinAx cable to replace the broken one. It looks
    like the cable was never properly made and was completely broken by this
    afternoon.

    After replacing the cables, we checked the busy signals from ROCs 1, 2 and
    8. The busy signals were 12 us wide for ROC 1 and 2 and about 40 us for
    ROC 8. We checked each signal separately and then all three together.
    With all three connected including ROC8 into B_IR input, the output of
    the BSY was 40 us.

    When we connected this signal to the FB input of the TS2 module, we found
    that the DAQ was constantly dead. I tried different combinations including
    having only ROC 8 connected into the three different inputs. As soon as
    we unplugged the ROC 8 busy, the DAQ would come back to live. Looking
    at the ROC 8 busy on the scope with the BSY output plugged into the
    FB input, the ROC 8 busy was always busy. Disconnecting this cable
    caused the ROC 8 busy to become 40 us again.

    The TM module appears to be doing the correct thing by "OR"ing the three
    signals together. But it seems that the TS2 input is somehow
    interpreting the signal in a strange way.

    MCC was ready to deliver beam, so we had to leave the hall. So I decided
    to leave the ROC 8 busy unplugged from the TM module until we can
    investigate this problem further.

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