User name R. Michaels
Log entry time 12:21:36 on January25,2001
Entry number 55701
keyword=Mods to trigger/DAQDuring the morning break before running e98108, I made the
following modifications and checks:
1. Reduced the coincidence window. The L-arm trigger signal is 48 nsec
wide (FWHM), the R-arm is 16 nsec. Taking into account that the minimum
overlap required to get a coincidence is 5 nsec, the expected coincidence
window is 48 + 16 - 10 = 54 nsec.
2. The default DAQ config is in buffered mode. If this causes problems, one
can download the "unbuff" config which has buffering turned off. Last two weeks
we've virtually no trouble with the fastbus noise which had caused extra hits in
TDCs and causes trouble for buffering. Apparently, the only time it happens is
when the hall is open, the shield doors open, and people are doing "noisy work".
Anyway, DAQ synch can & should be checked. See ~adaq/synch/README
3. Per request of the experiment, I unplugged the pulser from scintillator paddle #1
on S1,S2 plane on both spectrometers. So it only goes into paddle 3 now. This
should make the scaler measurement of EDT sensible.
4. fastbus reset GUI does not reset L-arm fastbus crate (roc 2). Neither Jack nor
I could fix this yet. Probably no big deal, one can usually "reboot" from the
telnet login.
5. Checked trigger timing. Even for the lowest momentum Kaons (1700 MeV/c,
I assume) for the upcoming few days, the trigger can remain the same. The TC
peaks show up at 170 and 240 nsec on R-arm and L-arm respectively, see figure.
FIGURE 1
