Author :
Bauer, G. ; Boyer, V. ; Branson, J. ; Brett, A. ; Cano, E. ; Carboni, A. ; Ciganek, M. ; Cittolin, S. ; Erhan, S. ; Gigi, D. ; Glege, F. ; Gomez-Reino, R. ; Gulmini, M. ; Mlot, E. Gutierrez ; Gutleber, J. ; Jacobs, C. ; Kim, J.C. ; Klute, M. ; Lipeles, E.
Abstract :
The CMS data acquisition system is designed to build and filter events originating from 476 detector data sources at a maximum trigger rate of 100 kHz. Different architectures and switch technologies have been evaluated to accomplish this purpose. Events will be built in two stages: the first stage will be a set of event builders called front-end driver (FED) builders. These will be based on Myrinet technology and will pre-assemble groups of about eight data sources. The second stage will be a set of event builders called readout builders. These will perform the building of full events. A single readout builder will build events from about 60 sources of 16 kB fragments at a rate of 12.5 kHz. In this paper, we present the design of a readout builder based on TCP/IP over Gigabit Ethernet and the refinement that was required to achieve the design throughput. This refinement includes architecture of the readout builder, the setup of TCP/IP, and hardware selection.
Keywords :
data acquisition; high energy physics instrumentation computing; local area networks; position sensitive particle detectors; readout electronics; transport protocols; trigger circuits; CMS data acquisition system; Compact Muon Solenoid; Myrinet technology; TCP/IP sockets; detector data sources; event builder; front-end driver builders; gigabit ethernet; hardware selection; single readout builder; switch technology; trigger rate; Buildings; Collision mitigation; Data acquisition; Detectors; Ethernet networks; Event detection; Filters; Switches; TCPIP; Throughput; CMS DAQ; Ethernet; Event Builder;
