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HK: Hadronen und Kerne

HK 13: Instrumentation II, Data Acquisition Systems

HK 13.2: Talk

Monday, March 16, 1998, 17:15–17:30, A

An ATM based system for transport and processing of online data* — •M. Münch, J. Friese, R. Gernhäuser, J. Homolka, A. Kastenmüller, P. Kienle, H.-J. Körner, and K. Zeitelhack — Physik Department E12, Technische Universität München, James-Franck-Straße, D-85748 Garching

The data acquisition system, that is currently built for the GSI HADES spectrometer, combines high performance CPUs for data processing with ATM for data transport.

At the front end, Power-PC VME-CPUs with 155 MBit/s ATM adaptors perform the readout. Concentrating and transporting the data is performed by an ATM switch with an internal bandwidth of 2,5 GBit/s. The data can be split and delivered to specialised or general purpose processors for event classification and filtering. At the back end, accepted events are passed to a server or workstation for writing to tape. A prototype of the data acquisition system was successfully used during a HADES beam time in summer 1997.

The design of the data acquisition is presented and the special techniques for using ATM as an transport for experimental data are discussed. The results of the test in summer 1997 are shown and the implementation of the production system for HADES is described.
^∗ support contract BMBF (06 TM 365)