Log entry time 19:08:22 on February 17, 2011

Entry number 347379

Followups:

• 347388 02/17/11 20:27 danez LHRS Mapping Problem - Followup

Today I was trying to fix issue of S1, which has un-correlated ADC and
TDC singal in replayed data. Here is what I did:

1, Checked cable connection.   All correct
2, Checked timing. Both ADC and TDC signals are in the gate (and STOP)
3, Looked at TDC and ADC signals in the scope. When turn off the HVs,
both disappear at the same time. Connection is good.
4, Turned off several PMTs' HV and took cosmic run. Did not see signals
of ADC and TDC for those channles that has HVs off. So the map in DB is GOOD.
5, Using a different cable for S1 TDC and move it to different channels
(from 80~96 to 0~15). Data Bas is updated in 20110217/db_L.s1.dat.Cosmic
Ray data is taking and will analyze it soo.

6, Analyzer:
  We guess there may be an error during data replay, since S1, S2m were
using 1875 TDC and now we changed to 1877. Although we verified the
cratemap and data base, which are updated, we may have to look carefuly
on whether the analyzer really treat it as 1877. David will analyze some
old data we took last week which inlucde S2m trigger and see whether S2m
has TDC&ADC un-correlated issue. If yes, the data are safe and we need to
work on analyzer. If not, S1 may has issues on itself and we need to fix
it asap.