DocumentCode :
861341
Title :
The DAQ system with a RACEway switch for the PHOBOS experiment at RHIC
Author :
Kulinich, Piotr ; Sarin, Pradeep ; Sukhanov, Andrei
Author_Institution :
Lab. for Nucl. Sci., MIT, Cambridge, MA, USA
Volume :
49
Issue :
5
fYear :
2002
fDate :
10/1/2002 12:00:00 AM
Firstpage :
2455
Lastpage :
2458
Abstract :
The PHOBOS data acquisition system based on a RACEway switching network is described. Occupying a single VME crate, the system utilizes 22 PPC750 CPUs working in parallel to compress data from 135 168 silicon pad detectors and an UltraSPARC VME host for event building and data storage. Lossless Huffman coding is used for compression; this reduces the event size fourfold. The two-host disk array is used to stage data before sending them over Gigabit Ethernet to the Relativistic Heavy Ion Collider (RHIC) central computing facility. All trigger and control logic is formed using universal programmable logic VME modules, which can be programmed in situ, even when the system is running. The event building and run control software is written using the ROOT framework. The slow control and configuration makes use of an Oracle database to store configuration and monitoring parameters. The system has been taking data from the PHOBOS experiment at RHIC since June 2000. The achieved data-taking rate is 280 events/s or 28 MB/s, with additional disk arrays it can potentially reach 80 MB/s.
Keywords :
data acquisition; data compression; high energy physics instrumentation computing; nuclear electronics; physical instrumentation control; programmable logic arrays; readout electronics; silicon radiation detectors; system buses; trigger circuits; DAQ system; Gigabit Ethernet; PHOBOS experiment; RACEway switch; RHIC; ROOT framework; Si; UltraSPARC VME host; VME crate; control logic; control software; data acquisition system; data compression; data storage; data-taking rate; disk arrays; lossless Huffman coding; silicon pad detectors; slow control; trigger; universal programmable logic; Data acquisition; Detectors; Event detection; Huffman coding; Memory; Programmable control; Programmable logic arrays; Programmable logic devices; Silicon; Switches;
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/TNS.2002.804729
Filename :
1046765
Link To Document :
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