From: Geary Eppley (eppley_at_physics.rice.edu)
Date: Sun Apr 20 2003 - 13:24:45 EDT
Hi Zhangbu,
Thanks for coming in and having a look.
Bill C., there were two problems. One was that scaler 14 which reflects
the TOFr special trigger went to zero at 11 am Friday. This scaler
includes an L0 busy veto. Zhangbu tested this just now while he was in and
all that was required was to start a run with TOFr trigger. This removed
the busy.
The remaining problem is a sky-high trigger rate without beam or even high
voltage. This will require a short access and can be fixed in 5 minutes if
it is the known hot channel, #38.
There is the possibility of additional hot channels from some
discriminator channels that latch on. These were discovered when the
TOFr trigger was first implemented and they were skipped over, but
unfortunately not recorded. When the trigger logic was rebuilt last
Wednesday, we didn't discover any latched discriminator outputs but they
could have re-occurred.
This will take about 10 minutes or less to find with a tree search. Either
Zhangbu or I can do this depending on who is closest.
I think we should wait for an opportunistic access (when RHIC is down) and
then request a short controlled access from main control.
Geary
On Sun, 20 Apr 2003, Xu, Zhangbu wrote:
> Hi, Geary:
<snip>
> It means that we do have a bad channel and we need an access.
> I don't know what happens to scaler 14. Maybe it is the same
> problem or possible that the busy from local daq stuck. This
> need to be checked as well. We should put in a request for access
> ~15minutes!
>
>
> Thanks!
> Zhangbu
>
This archive was generated by hypermail 2.1.4 : Thu Jul 24 2003 - 00:39:40 EDT