hi,
now that we have the flasher incorporated into the trigger, it should
be very easy to do this on a run-by-run basis, just plot the flasher tdc
top/bottom spectra, and use this to calibrate the offsets for each run,
and maybe check if it has changed since last time as a possible trouble
flag.
--chris
Adrian T Sindile wrote:
>Hi, Chi!
>
>
>
>>It could be a real shift in electronics or due to a temporary change in
>>offset file. No way to tell at this moment. It may be useful to save
>>offset values with our data ntuple. it takes just another 200 float
>>numbers at most into our root file.
>>
>>
>
>This is exactly the reason I was advocating writing these offsets to the
>BLAST_physics MySQL database on a run-by-run basis. The SC_TDC_RUN table
>contains a field T0 just for this purpose...
>So far Peter has been writing these offsets to files once in a while,
>on our general assumption that these numbers do not change.
>
>I think it makes sense to write them to the database (once Pete's offset
>code is ready I can modify it so that we dump these numbers to the
>database, or I can show him an example of how to do that - but we will
>have to run this code after every valid run, or integrate it in lrn!).
>Then the analysis would just retrieve these numbers and use them for each
>run, instead of assuming (like so far) that everything is stable...
>
>Or we could also save them to our root files - but I wanted to point
>out that the database alternative has been there waiting for these
>numbers, the database was designed for this after a discussion with Tim
>Smith who foresaw the need for it a year and a half ago.
>
>Adrian
>
>
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