Refresher: Since we plugged the S2, S1 and Cerenkov tdc signal in the high resoltuion tdc 1875: we have not seen any tdc signal for these detectors out of the analyzer. I plugged a nim pulser in place of the signal out of the S2L9 pmt and looked at the signals (gate and signal) at the face plate of the TDC. All other S2 pmts were off (HV off). Below is the scope picture: the blue line is the signal that goes in the front input of the TDC called "cmn" and the yellow signal is the S2L9 signal. So the pmt signal arrives 200ns before the gate. Is this what we really want? The lecroy documentation on the tdc1875A says that this tdc is working on the "Common Start Mode of Operation". I'll keep on poking at this tomorrow morning. Note: I left the pulser and the scope plugged.