1) bigcal_prot(rcs)_nsparse (=20 presently): this tells the pedestal determination procedure how many ADC channels to use in the hardware pedestal suppression.
2) bigcal_prot(rcs)_min_thresh (=10 presently): this tells the engine the lowest software threshold to use when analyzing the data. 3) bigcal_prot(rcs)_max_thresh (=25 presently): this tells the engine the highest software threshold to use when analyzing the data.
The ped. width is determined for each run using the ped. events. If 2.5*ped width lies between the limits described above, then that number will be used as a software threshold. If 2.5*sigma is greater than the max, then the max of 25 channels is used, or if it is less than 10, then the min of 10 channels is used. These parameters are user-adjustable and do not affect the data. On the other hand, the "nsparse" parameters determine what thresholds to program into the ADCs. A file is generated for each run, but the hardware thresholds are NOT updated automatically. If you want to update them, then you have to manually copy one of the files generated by the engine and copy it into the file that is used to load the thresholds into the ADCs.
In this instance, the beam current was off, so the engine determined
artificially low ped. widths, setting some of the thresholds lower than
usual, which is why you get more hits than usual. This is not a problem.
A copy of this log entry has been emailed to: pentchev@jlab.org, weiluo@jlab.org