[Halld-pid] Configuration of TOF ADCs and TDCs

[Alexander Somov]

Hi Sascha,

> or to fADC hits. It looks like the change in the trigger latency (when
> switching from the TOF standalone trigger to the current FCAL trigger)
> was accounted for only in the FADC250 configuration. fADC latency
> has been changed from 510 to 910 samples (or from 2040 ns to 3640 ns).
> TDC1290 latency still remains at the same 2000 ns value as before.
> I think, config parameter TDC1290_W_OFFSET also needs to be
> adjusted from -2000 to -3600. What I'm not sure about is if the current
> config file 'fcal_all_891a.conf' is the only place to make such change,

As I wrote, the fcal trigger latency is set to about 3.4 usec. So
both fadc and tdc windows should be adjusted  (use TDC1290_W_OFFSET
for this). fcal_all_891a.conf should be the only place


> (/gluex/Subsystems/TOF/parms/common/fadc250/roctof1_fadc250_ver1.cnf)
> has DAC values which are like 60-80 units lower than the current values in
> /gluex/CALIB/ALL/fadc250/roctof1_fadc250_Run_891.cnf.
> This is a large difference in the DAC old and new calibrations and should
> result in a large baseline difference as well. However, the current baselines
> are still in the vicinity of 200 with the new DAC values the same way they
> were at 200 with the old values in the past. So, something has changed
> from then to now which required large readjustment of DACs. But I
> don't have a clue what has changed actually. Does anyone know?

Sergei has probably recalibrated DAC values (set them to fadc cnt 100),
you was using 200 before. We'll need to agree on the DAC values we are
going to use. I

> More importantly, what do we do with the current 190-to-206 large spread
> of the baselines? Does tis means we need to recalibrate FADC250 again
> more carefully this time?

How do you measure the spread ? If you do it with the triggered data you 
can potentially 'bias' your pedestal position. Did you select a
few samples before the pulse ?

Cheers,
       Sasha