A multiprocessor controlled data acquisition system

We have designed and constructed a multiprocessor controlled data acquisition system (DAS) to meet the requirements of an extensive air shower array currently under construction on the University of Notre Dame campus, project GRAND. The DAS hardware and software have been designed to handle a large amount of data in a short time so that astrophysical burst events, which can generate over a million tracks per event in an ultrahigh energy extensive air shower, can be successfully recorded. A double-height VMEbus system hosts the central processing units, the interfaces for peripherals, and the custom-designed electronics. The use of synchronous data transmission from the detectors in the air shower array to the DAS allows the system to handle a maximum data burst rate of 96 Mbytes/s. A powerful single board microprocessor designed by the Advanced Computer Program group at Fermi National Accelerator Laboratory and manufactured by Omnibyte, Inc., fulfills the on-line data acquisition requirements of this high speed system. (orig.)