A distributed real-time system for event-driven control and dynamic data acquisition on a fusion plasma experiment

A distributed real-time trigger and timing system, designed in a tree-type topology and implemented in VME and CAMAC versions, has been developed for a magnetic confinement fusion experiment. It provides sub-microsecond time latencies for the transport of small data objects allowing event-driven dis charge control with failure counteraction, dynamic pre-trigger sampling and event recording as well as accurate simultaneous triggers and synchronism on all nodes with acceptable optimality and predictability of timeliness. T his paper describes the technical characteristics of the hardware component s (central unit composed by one or more reflector crates, event and synchro nism reflector cards, event and pulse node module, fan-out and fan-in modul es) as well as software for both tests and integration on a global data acq uisition system. The results of laboratory operation for several configurat ions and the overall performance of the system are presented and analysed. (C) 2000 Elsevier Science S.A. All rights reserved.