The signals from the detectors are arranged in the FEMC input to obtain separate auto-triggers for the 3 quadrant detectors. In total there are 6 auto-trigger signals, 2 for each detector, one obtained with LLT and the other with HLT.
The LLT is set to the minimum value compatible
with the electronic noise and it allows to trigger m.i.p. signals.
The HLT is about 2 times the mean m.i.p. signal amplitude, which
corresponds to the minimum energy released by protons going at least
through the Q
detector.
The auto-trigger outputs from the FEMC modules are combined into external VME modules to provide the experimental triggers. The VME modules receive as input the ECL signals from the auto-trigger section of the FEMC module, providing NIM translation and the required logical coincidences.
Two triggers have been implemented: one
for pions and high energy protons (T
); the other for low energy protons
(T).
The pion T trigger is realized by the triple LLT coincidence between the 3
quadrant detectors Q, Q and Q
.
The T trigger is obtained by the double coincidence between the quadrant
detectors Q and Q, using the HLT.
The readout and acquisition is started by one of the two experimental triggers (ORed).