Hi Hartmut,  Steve,
 
Hartmut asked about the TDC calibration on Saturday.
 
I have set up the DAQ as follows:
 
 
   TRIGGER --- FANOUT --- CORBO
                       |
                       -- TDC Common Start
                       |
                       -------------- NIM-ECL ===== TDC Input #1
                       |
                       --[ +18 ns ]-- NIM-ECL ===== TDC Input #2
 
where  '==='  is an IDC16 flat-twisted-pair cable direct from
the NIM-ECL to the TDC.
 
I include the monitoring histograms from around 1000 triggers
below.  As you can see from the stats,  the difference is around
106 TDC counts.  Measured on the scope at the NIM outputs of the
NIM-ECL-NIM,  the time difference was just on 20 ns, whereas
the cables used for delay added up to 18 ns,  so allowing
for the RMS and other errors,  the calibration is pretty close
to the nominal 180ps/count.
 
If possible,  I would like to keep this cable installed on the
TDC as it is much neater than at CERN.   The  NIM-ECL-NIM unit can
take both NIM (Lemo) and ECL (twisted-pair IDC) inputs,  giving
the 8 ECL output channels.  I would also like to keep these two
calibration inputs also as they give some confidence both the
TDC and the DAQ are working.   We are currently always reading 5 TDC
hits,  so there is some room.  More can be added if needed.
 
 
Gareth