Filters

In order to minimize network and frontend system load there are mechanisms to transfer only events of interest to your "backend" computer. This feature is essential for FOPI Phase 2 experiments to exclude very large events. The following commands handle event filters for subevents.

   raw/select/set <type> <subtype>     # to select exactly 1 subevent           
   raw/select/reset                    # to reset a list of  subevents
   raw/select/add <type> <subtype>     # to append a subevent to a list
   raw/select/show                     # show the list of subevents 
   raw/select/off                      # suspends  selection,                   
                                       # but keeps subevent list                
   raw/select/on                       # resumes selection after /off

Note that in order to minimize the number of dis- and reconnections raw/sel/add does not reopen TDAS connections automatically.

In addition one can specify an offset from the event start, a hex bit mask and a mask operation:

  ra/sel/set <t> <st> <o> <xmask> ==   # if ( evt[o] == <xmask> ) accept 
  ra/sel/set <t> <st> <o> <xmask> &&   # if ( evt[o] && <xmask> ) accept
  ra/sel/set <t> <st> <o> <xmask> &=   # if ( (evt[o] &  <xmask>) == <xmask> ) accept

The default is '=='. Examples:

   ra/sel/set 2001 9212         ==     # selects events of type 2001 and subtype 9212
   ra/sel/set 140 9101 1 12FFF6 ==     # selects error events of type -10 and subtype 18