I have had some question recently, I it might be useful to iterate some of the fact of how the triggers latches are setup. The trigger system has 8 inputs, labelled trigger 1-8; 7/8 are non-beam related i.e. pulsers+sync events; A latch is made 3 times for each event a) once before the scaledown -> bit 0-7 b) after scaledown bit 8-15 c) once before the enable setting bit 16-23 Thus the second 8 bit tells what trigger started the gates , while the first 8 tells what triggers were set by the hardware for a given event. It is important to beware this difference when evaluating cross sections. Thus for scaledown events one should not test the 16bits, but only the eight to decide what kins of trigger it is, but use the second set for evaluating rates/ratios and cross sections. Flemming ------------------------------------------------------ Flemming Videbaek Physics Department Brookhaven National Laboratory tlf: 631-344-4106 fax 631-344-1334 e-mail: videbaek@bnl.
This archive was generated by hypermail 2b30 : Thu Sep 06 2001 - 22:04:37 EDT