A flexible IBM-PC based data acquisition system for nuclear physics experiments

A SCSI-bus data acquisition module, which serves up to 15 12-bit NIM-standard spectroscopy ADCs, is described. When operating in cascade mode, 8 modules may serve up to 112 ADCs. The module was primarily developed for use in nuclear physics experiments. A typical system configuration consists of a data acquisition module, a SCSI-bus mass storage device (Video-8 or DAT) and a personal computer system controller. The latter also serves as a monitor allowing on-line evaluation of the quality of the incoming experimental data. The module has a micro-controller, a SCSI-bus controller and a field programmable gate array as main components. The gate array implements most of the ADC arbitration and read-out logic. The module was designed to allow a high degree of flexibility. This was accomplished by allowing the control programs and gate array configurations to be down-loaded from the system controller. The design thus permits rather extensive functional modifications without changing the hardware. It also allows thorough testing by down-loading test programs and test configurations. (orig.)