Qweak R1 Software

Slow Control GUI

MEDM

use EPICS se set HV channels and alarms

Lab View

rotation control.

VFAT setup

The VFAT setup is done through a web interface.

GEM data processing

The GEM detector contains 6 VFAT cards which are used to digitize the charge from an ionization event. Each channel of the VFAT is associated with a charge collection strip within the GEM ionization chamber. Once triggered the VFAT card will transfer 192 bits (Defined in Figure 8 of the VFAT manual V2.0) from each VFAT card to separate I/O channels on a CAEN V1495 module.

CODA file to Tracking data structure

A ROC will transfer GEM data from a CAEN V1495 to the host DAQ computer. At the local institution there will only be one element of the Qweak tracking software. Once the ROC is writeing data to a CODA file from the V1495 we will need to write software which will take the raw data and create a data structure for tracking. The data structure for tracking, in the case of R1, will contain the distance of the elastic scattering event from the beam pipe center ([math]R[/math]) and [math]\phi[/math] representing the local polar angle in which [math]\phi=0[/math] at the center of the detector.

The SVN repository for the Qweak Analysis and tracking software is at

https://qweaksvn.jlab.org/repos/QwAnalysis/trunk/Analysis

Qweak wiki describing the software is at

https://qweak.jlab.org/wiki/index.php/Installation_and_compilation

GEM data header file is located in

QwAnalysis/ Tracking/include/QwGasElectronMultiplier.h

The above defines the processed data structure, it includes a ProcessEventBuffer function to strip data out of the raw CODA data buffer, defines the function to create a QwHit for each r and phi strip hit

Int_t ProcessConfigurationBuffer(const UInt_t roc_id, const UInt_t bank_id, UInt_t* buffer, UInt_t num_words){return 0;};  /* contains IPreamp info if needed occurs during Prestart*/

 Int_t ProcessEvBuffer(UInt_t roc_id, UInt_t bank_id, UInt_t* buffer, UInt_t num_words){return 0;};/* filters out VFAT data from CODA bank*/

 void  ProcessEvent() /* fills hit list */

QwGasElectronMultiplier->fHits

create a tracking source file in the subdirectory which contains the actual code to do the above

QwAnalysis/Tracking/src/QwGasElectronMultiplier.cc

The above *.cc file also needs a LoadMap function to read a prminput file (located in Tracking/prminput/)

an example of which is shown in

Tracking/src/QwDriftChamber.cc

Int_t QwDriftChamber::LoadChannelMap(TString mapfile){
  TString varname, varvalue;
  UInt_t  chan, package, plane, wire, direction, DIRMODE;
  DIRMODE=0;
  

  fDirectionData.resize(2);//currently we have 2  package - Rakitha (10/23/2008)
  fDirectionData.at(0).resize(12); //currently we have 12 wire planes in each package - Rakitha (10/23/2008)
  fDirectionData.at(1).resize(12); //currently we have 12 wire planes in each package - Rakitha (10/23/2008)

  QwParameterFile mapstr(mapfile.Data());  //Open the file

  while (mapstr.ReadNextLine()){
    mapstr.TrimComment('!');   // Remove everything after a '!' character.
    mapstr.TrimWhitespace();   // Get rid of leading and trailing spaces.
    if (mapstr.LineIsEmpty())  continue;

Another simpler eaxample is in

Tracking/src/QwMainDetector.cc

Int_t QwMainDetector::LoadChannelMap(TString mapfile){
  TString varname, varvalue;
  TString modtype, dettype, name;
  Int_t modnum, channum;

  QwParameterFile mapstr(mapfile.Data());  //Open the file
  while (mapstr.ReadNextLine()){
    mapstr.TrimComment('!');   // Remove everything after a '!' character.
    mapstr.TrimWhitespace();   // Get rid of leading and trailing spaces.
    if (mapstr.LineIsEmpty())  continue;

    if (mapstr.HasVariablePair("=",varname,varvalue)){
      //  This is a declaration line.  Decode it.
      varname.ToLower();
      UInt_t value = atol(varvalue.Data());
      if (varname=="roc"){
        RegisterROCNumber(value);
      } else if (varname=="bank"){
        RegisterSubbank(value);
      } else if (varname=="slot"){

DataBase info

The following run-by-run information should be included in a database table

Two tables:

   R1G1  = Region 1 GEM Detector 1
   R1G2  = Region 1 GEM Detector 1

Each of the 2 tables has 2 High Voltage entries, an Octant location, and 6 sub tables one for each VFAT electronics card

HVdrift
HVGEM
Octant
VFATChipID_A 
VFATChipID_B
VFATChipID_C
VFATChipID_D
VFATChipID_E
VFATChipID_F

Each of the 6 electronics cards (VFATChip_ID) above have the following information

IPreampIn	
IPreampFeed	
IPreampOut	
IShaper		
IShaperFeed	
IComp	
UpsetReg	
Lat	
VThreshold1	
VThreshold2	

In addition to the above variables each chip has 128 Channels which can contain TrimDAC offsets and a mask

ChanReg_1_Mask	 
ChanReg_1_TrimDAC
ChanReg_2_Mask	
ChanReg_2_TrimDAC
ChanReg_3_Mask	
ChanReg_4_TrimDAC

....

ChanReg_128_Mask	
ChanReg_128_TrimDAC

At the end of a tracking run each of the above chips will have "scaler" counts recorded with the following names

HitCount0	
HitCount1	
HitCount2

References

VFAT manual

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