User Configurable Event Selection

As described earlier four control words ( fev.ctlw1, fev.ctlw2, fev.ctlb1, fev.ctlb2) are used to distribute the events (the first two operate on a equal basis, the other two on a bit basis). The conditions are implemented as a macro and can therefore easily be changed by the user (file $DD_INC/dd_fifo_conditions.h). The relevant listing is given below:

Code fragment for deciding whether to put the event into this fifo

 
		      else if (p2f->fhdr.fmode == FMODE_COND){

		  		      if ( (p2f->fhdr.fctlw1 != -1) & & FIFO_COND1 )

		 		 		       this_fifo = i;

		 		        if ( (p2f->fhdr.fctlb1 != -1) & & FIFO_COND2 )

		 				          this_fifo = i;

		 		        if ( (p2f->fhdr.fctlw2 != -1) & & FIFO_COND3 )

		 				          this_fifo = i;

		 		        if ( (p2f->fhdr.fctlb2 != -1) & & FIFO_COND4 )

		 				          this_fifo = i;

		      }

Fifo conditions as implemented in $DD_INC/dd_fifo_conditions.h

#define FIFO_COND1 (p2f->fhdr.fctlw1 == fev.ctlw1)
#define FIFO_COND2 (p2f->fhdr.fctlb1 & fev.ctlb1)
#define FIFO_COND3 (p2f->fhdr.fctlw2 == fev.ctlw2)
#define FIFO_COND4 (p2f->fhdr.fctlb2 & fev.ctlb2)