ACD_Pha: ACD Zero-Suppression register settings

The ACD_Pha precinct controls the digital zero suppression thresholds for the PHA (long shaper) data. Any PHA value above the threshold will be read out and built into the event. Of course for non-zero suppressed mode all of the data will be read out.

• Registers:
  

  Group	Register Name	Instances	Multiplicity	Subsections	Type	Width (bits)
  ARC	pha_threshold	12	18	1	int	12

  The pha_threshold registers are called pha_threshold_0 to pha_threshold_17.

• Methods: BCAST or CALIB
  CALIB uses an the pedestal calibration and adds an offset (default is 15 counts above pedestal).
• Ancillary files:
  ACD_PedestalCalibration: this file contains the pedestal value for each channel.
• Constants:
  countsAbovePedestal: offset above pedestal to set the zero-suppression threshold, nominally 15.