GROUP_VETO_BITMAP

Short description

This data group contains data on which segments of the DEA, CPV and EV/BV counters fired.

Summary

• Include file: itypes.h
• Data structure:

  typedef struct
  {
    int32 length;
    int32 flags;
    uint32 cpva;
    uint32 cpvb;
    uint32 cpvc;
    uint32 dea;
    uint32 ev;
    uint32 bv;
  
  } vetoCounters_t;
  

• Related functions:
  • int unpackVetoes(void *event,int eventLength);
• Related data groups:
  • GROUP_MISC_ADCS
  • GROUP_TRIGGER_TDCS
  • GROUP_VETO_HITS
• Related Hist histograms:
  • CPVx-TDC --- TDC distributions
  • CPVx-ADC --- ADC distributions
  • CPVx-ADC-noTDC --- ADC without corresponding TDC hit
  • CPVx-ADC-haveTDC --- ADC with a hit in the corresponding TDC
  • DEAx-TDC --- same as CPV histograms
  • DEAx-ADC
  • DEAx-ADC-noTDC
  • DEAx-ADC-haveTDC
• Related Map Manager items:
  • Map File: vetoes.Map
  • Subsystems: c, cpva, cpvb, cpvc, dea and evbv.
  • Items: adc_min, tdc_min and tdc_max.
• Source code: libanalyzer/unpackVetoes.c

Discussion

The GROUP_VETO_BITMAPS group contains information about "binary"-type detectors that can only be in two states- empty or hit. Each detector has corresponding bits in the data structure that is set to 0 if the detector is empty or to 1 if the detector has a hit.

To decide if the detector has a hit, the program uses the TDC and ADC information.

The TDC has a hit if it's value is within bounds defined by the tdc_min and tdc_max parameters for the detector. The values of both parameters are stored in the Map Manager file.

The ADC has a hit if it's value is above adc_min. The value of this parameter is also stored in the Map Manager file. Normally adc_min is calculated using the corresponding ADC pedestal and sigma (width of the pedestal). See the code in daq.exes/processVetoThresholds.c for an example.

See also the CPVC/DEA documentation.

Data structure fields

• length: length of the data structure in bytes
• flags: bimapped, no bits are currently defined, normally contains zero.
• cpva: bitmapped hits in CPVA:
  • bits 0-1 correspond to ADC hits and
  • bits 16-17 to the TDC hits of the two CPVA phototubes.
• cpvb: bitmapped hits in CPVB:
  • bits 0-1 correspond to ADC hits and
  • bits 16-17 to the TDC hits of the two CPVB phototubes.
• cpvc: bitmapped hits in CPVC:
  • bits 0-5 correspond to ADC hits and
  • bits 8-15 are set to "1" if the DEA charged particle tagging was done and the DEA bits 8-15 were set.
  • bits 16-21 to the TDC hits of the six CPVC phototubes.
• dea: bitmapped hits in DEA:
  • bits 0-5 correspond to ADC hits in the six DEA phototubes.
  • bits 8-11 are the "charged track" tags for the "front-face" of the DEA. The charged track hits are measured on the front face of the DEA. Bit 8 is set when the top segment of the DEA is hit by a charged track, bit 9- the "MPS-closed-side" segment, bit 10- "MPS-open-side" and bit 11- bottom segment.
  • bits 12-15 are same as bits 8-11 except that the charged track hits are measured on the "back-face" of the DEA.
  • bits 16-21 to the TDC hits in the six DEA phototubes.
• ev: bitmapped hits in EV:
  • bits 0-1 correspond to ADC hits and
  • bits 16-17 to the TDC hits of the two EV phototubes.
• bv: bitmapped hits in BV:
  • bits 0-1 correspond to ADC hits and
  • bits 16-17 to the TDC hits of the two BV phototubes.

Bugs

• The phototube assignments are documented elsewhere.
• EV and BV code is not implemented.

CO 1996-Aug-20