Author :
Bauer, G. ; Boyer, V. ; Branson, J. ; Brett, A. ; Cano, E. ; Carboni, A. ; Ciganek, M. ; Cittolin, Sergio ; Erhan, S. ; Gigi, D. ; Glege, Frank ; Gomez-Reino, R. ; Gulmini, M. ; Mlot, E. Gutierrez ; Gutleber, J. ; Jacobs, C. ; Kim, J.C. ; Klute, M. ; Lipe
Abstract :
The CMS Data Acquisition System is designed to build and Alter 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 FED Builders. These will be based on Myrinet technology and will pre-assemble groups of about 8 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 72 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 optimization that was required to achieve the design throughput. This optimization includes architecture of the Readout Builder, the setup of TCP/IP, and hardware selection.
Keywords :
data acquisition; high energy physics instrumentation computing; muon detection; nuclear electronics; position sensitive particle detectors; readout electronics; Alter events; CMS; DAQ; Gigabit Ethernet network; Myrinet technology; compact muon solenoid; data acquisition system; detector data sources; readout builders; Buildings; Collision mitigation; Data acquisition; Design optimization; Detectors; Ethernet networks; Event detection; Switches; TCPIP; Throughput;
