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User name R. Michaels
Log entry time 11:22:50 on September30,2010
Entry number 333196
Followups:
keyword=roc4 woes and revival inclu bpm/rasterLast night the gate cable was unplugged from roc4 slot 16 resulting
in no data from this crate in run 6844 for example, and I suppose
for all the other runs too. This was fixed this morning.
Now in run 6862 with bpm/raster cable deliberately unplugged
to see pedestals we see typical data like this for the 12 channels
in roc4, slot 24, chan 0-11 (where bpm/raster lives).
These are ADC pedestals but NOT "BPM pedestals" -- those
would need to be measured in a special run with forced gain=0
resulting in delta-function peaks that are far from ADC pedestal.
Anyway, here are the ADC pedestals run 6862
Left HRS spot++ raw data 0 521
Left HRS spot++ raw data 1 474
Left HRS spot++ raw data 2 451
Left HRS spot++ raw data 3 443
Left HRS spot++ raw data 4 565
Left HRS spot++ raw data 5 577
Left HRS spot++ raw data 6 630
Left HRS spot++ raw data 7 663
Left HRS spot++ raw data 8 544
Left HRS spot++ raw data 9 528
Left HRS spot++ raw data 10 503
Left HRS spot++ raw data 11 455
Next, we plug in the bpm/raster ribbon cable, so the signals
should shift to the quiescent offset of the electronics which
should be not too far from the quasi-DC level of beam data.
Run 6863 snapshot :
Left HRS spot++ raw data 0 3244
Left HRS spot++ raw data 1 3081
Left HRS spot++ raw data 2 3695
Left HRS spot++ raw data 3 3624
Left HRS spot++ raw data 4 3156
Left HRS spot++ raw data 5 3248
Left HRS spot++ raw data 6 4603
Left HRS spot++ raw data 7 4582
Left HRS spot++ raw data 8 2875
Left HRS spot++ raw data 9 3240
Left HRS spot++ raw data 10 2766
Left HRS spot++ raw data 11 2644
The pedestal and signal for the first 6 channels look like
fig 1. The other 4 channels look similar but I'm too lazy
to post another figure.
BPM/raster data should be ok now.
FIGURE 1
