last Wednesday, during the first run after calibrations, the interERP
LeCroy 2228A TDC module on uVax3 started giving a lot of No Q responses.
Twiggling cables (start cable especially) this problem disappeared
by itself but some overflow values started for all 3 channels of
the module. We excluded uVax3 from ACQ. (starting from run 18195)
to work on this module and the No Q responses started again. They
stopped only by unplugging the clear cable from the module front panel.
During our debugging (all the cables checked, clear cable connection
to the module input remade, etc...), and looking at stop and clear
signals timing, we noticed NO Q responses whenever there was difference
of 800usec (late clear) between the two signals. Probably there are
problems on the Computer Busy Manager in the InterERP module and/or
on the uVax3 computer busy stuff. To check this we have to wait for
next Wednesday...
Starting from run 18199, we are running with the full MACRO configuration
(all three uVaxes) but we decided to unplug the clear cable from the
TDC module to avoid No Q responses that could cause run crash.
This is reflected on a poor data quality for uVax3 InterErp:
~ 35% overflows on SM5, ~ 45% on SM6 and ~ 60% on South face.
We hope to solve the problem as soon as possible.
A presto,
Nicola