UA2 trigger and data acquisition

The UA2-detector mainly consists of a track detection system without magnetic field, surrounded by calorimeters. The main triggers are formed by adding the analog signals from the electromagnetic calorimeters to 'energy' clusters and applying a threshold to them. These clusters are also converted to digital values in 2.5 mu sec, and are available for more sophisticated with a processor which may be added later. The data acquisition is done by means of a VAX 11/780 through a ROMULUS/REMUS system. Four minicomputers can simultaneously 'spy' on part of the data acquired by the VAX. During beam-off periods, parts of the detector electronics can be decoupled from the VAX and be put under control of a minicomputer. Thus several detector arts can be simultaneously and independently debugged. (4 refs).