Log entry time 23:41:49 on February 17, 2011

Entry number 347408

I turn  off several HVs of S1 and S2, and compare the data of certain
channels with HV off in Run 1496 with the data of same channels with HV
on in Run 1495.

I only plot two PMTs of S1 and S2m respectively, but you already can see
something:

1, Again, The map is correct
2, There are other sources to provide most of the TDC signals about 1500
channels. EDTM? But it has much lower rate, as I understand.
3, S2m has two peaks for both ADC and TDC. For ADC, first one is
pedestal, but is second one the EDTM? For TDC, I can not explain why
there still has two peaks, since pedestal should not give TDC signals.

I really don't know the timing has an issue since I checked it many
times, but it would be helpful if someone would like to do a cross check.

comparation between different Runs in the same channel

comparation between different PMTs in the same Run 1496