The Time History Module: A Fastbus interfaced Logical Analyzer For Detector Monitoring And Other Applications

A first prototype of a FASTBUS-interfaced logical analyzer module usefully employable in detector and / or trigger system monitoring is described. Four of these time history modules (THM’s) have been successfully utilized in the NA31 experiment at CERN from 1985-1989, principally to control the purity of the accepted events. These THM’s have a built-in interface to the trigger system (based on finite state machine technique), a double input buffer, and a 20-MHz sampling clock. The best features of the THM are the glitch capture, the fully programmable sampling time interval, the fast double-input buffer, the separate readout buffer, the data compression capability, the high time resolution, the FASTBUS block-reading, and the easy and flexible triggering. Technological improvements are now possible in storage capacity, speed, programmability, and power dissipation.