Hi, 

this year the mapping of the CTB ADC values in the 
L0 trigger changed with the conversion of ADC values 
to MIPS for the 'productionCentral' trigger setup. 
This change does not affect the  central trigger 
itself, but it allows to run the topology  trigger 
in parallel to it.  For the analysis only the CTB-ADC sum 
as calculated from StEvent will be affected by the different 
mapping. So far there is no automated procedure yet to switch
between ADC sum and MIP sum, since the CTB mapping is done 
deep down in the L0 configuartion. So this is meant to be a 
heads-up. Please find the details below, comments are welcome. 

                Sorry for the inconvinience 
                      Falk 
------------------------------------------
The CTB sum can be calculated from the adc values given for each slat. 

   StCtbTriggerDetector* ctb=0;
   StTriggerDetectorCollection* trg = event->triggerDetectorCollection();
   if ( trg ) {  ctb = & trg->ctb();  }

   ctbSum=0;
   if(ctb){
    for(UInt_t i=0; i < ctb->numberOfTrays(); i++){
      for(UInt_t j=0; j < ctb->numberOfSlats(); j++){
        ctbSum += ctb->mips(i,j,0);
      }
    }
  }
  
  In the 2000 data ctb->mips(i,j,0) contained an 
  8 bit ADC value for each slat.  | 7 ...... 0|

  Bit zero was actually overridden by a  timing bit, 
  indicating if the  leading edge of the CTB-pulse was 
  detected within a 20 ns   timing window. 
  So more truthfully it looked like |7 ......1 | T |
  Which did not realy matter and so the timing bit was just 
  summed up. 

  For the central data in 2001 the mapping looks as follows: 
  The 8 bit ADC value is converted to the number of Mips (a 6bit number)
  by the gain of the CTB (basically a division by five)
  and the Timing bit is conserved. Bit7 is now always 0
  such  that.   | 7 | 6 ..(MIPS).. 1 | T |
                          
  To get the correct number of MIPS used by the trigger 
  the line in the code above has to be now            

        ctbSum += ( ctb->mips(i,j,0) > 1 );

    If this conversion is not done, i.e. the mip values are 
  just added up as last year, the CTB  ADC sum will be a factor 
  of 2.5 smaller than last year ( /5 for gain correction *2 for 
  timing bit shift)

                                Falk 
(


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