User name R. Michaels
Log entry time 09:29:46 on November 6,2000
Entry number 51585
keyword=CODA event types (poss. origin of dp anom ?)I remind you that CODA event types unfortunately don't mean
very much, especially if prescale factors are all one. This unhappy
situation was explained in halog 48497 (Sept 29), point 2. One should
use the ``trigger latch pattern'', a bit pattern that tells the real event type.
Also, rememeber that all fastbus is read for all events, with timing tied
to the local scintillators. If you can tell that a CODA event N is actually
a type K, then it is. Event type decoding: see ~rom/evchk/README.
Below is a graph of the latch pattern versus CODA event type, for a recente
run 1116, showing for example that sometimes CODA thinks its event
type 1 but actually it is 5. Maybe it explains ``dp anomaly" ? When Jack
puts in the faster handshake cables, this issue will disappear. Info also at
hallaweb.jlab.org/equipment/daq/trigsetup_coinc.html
FIGURE 1
