The ATLAS ReadOut System (ROS) receives data fragments from ∼1600 detector readout links, buffers them and provides them on demand to the second-level trigger or to the event building system. The ROS ...is implemented with ∼150PCs. Each PC houses a few, typically 4, custom-built PCI boards (ROBIN) and a 4-port PCIe Gigabit Ethernet NIC. The PCs run a multi-threaded object-oriented application managing the requests for data retrieval and for data deletion coming through the NIC, and the collection and output of data from the ROBINs. At a nominal event fragment arrival rate of 75kHz the ROS has to concurrently service up to approximately 20kHz of data requests from the second-level trigger and up to 3.5kHz of requests from event building nodes. The full system has been commissioned in 2007. Performance of the system in terms of stability and reliability, results of laboratory rate capability measurements and upgrade scenarios are discussed in this paper.
In the ATLAS experiment at the LHC, the ROD Crate DAQ provides a complete software framework to implement data acquisition functionality at the boundary between the detector specific electronics and ...the common part of the data acquisition system. Based on a plugin mechanism, it allows selecting and using common services (like data output and data monitoring channels) and developing software to control and acquire data from detector specific modules providing the infrastructure for control, monitoring and calibration. Including also event building functionality, the ROD Crate DAQ is intended to be the main data acquisition tool for the first phase of detector commissioning. This paper presents the design, functionality and performance of the ROD Crate DAQ and its usage in the ATLAS data acquisition system and during detector tests.
Hardware data emulators are used to deploy a large-scale model of the ATLAS data acquisition architecture. The emulators, based on FPGAs and on the Alteon gigabit Ethernet NIC, are described, and ...their performance determined. The emulators are used in the large-scale test bed; sample results are presented.
A fully instrumented slice of the ATLAS detector was exposed to test beams from the SPS (Super Proton Synchrotron) at CERN in 2004. In this paper, the results of the measurements of the response of ...the barrel calorimeter to hadrons with energies in the range 20–350
GeV and beam impact points and angles corresponding to pseudo-rapidity values in the range 0.2–0.65 are reported. The results are compared to the predictions of a simulation program using the Geant 4 toolkit.
Using Linux PCs in DAQ applications Unel, G.; Ambrosini, G.; Beck, H.P. ...
IEEE transactions on nuclear science,
04/2000, Letnik:
47, Številka:
2
Journal Article
Recenzirano
Odprti dostop
ATLAS Data Acquisition/Event Filter "-1" (DAQ/EF1) project provides the opportunity to explore the use of commodity hardware (PCs) and Open Source Software (Linux) in DAQ applications. In DAQ/EF-1 ...there is an element called the LDAQ which is responsible for providing local run-control, error-handling and reporting for a number of read-out modules in front end crates. This element is also responsible for providing event data for monitoring and for the interface with the global control and monitoring system (Back-End). We present the results of an evaluation of the Linux operating system made in the context of DAQ/EF-1 where there are no strong real-time requirements. We also report on our experience in implementing the LDAQ on a VMEbus based PC (the VMIVME-7587) and a desktop PC linked to VMEbus with a Bit3 interface both running Linux. We then present the problems encountered during the integration with VMEbus, the status of the LDAQ implementation and draw some conclusions on the use of Linux in DAQ applications.
Fibre Channel equipment has been evaluated in the environment of the ATLAS DAQ prototype “−1”. Fibre Channel PCI and PMC cards have been tested on PowerPC-based VME processor boards running LynxOS ...and on Pentium-based personal computers running Windows NT. The performance in terms of overhead and bandwidth has been measured in point-to-point, arbitrated loop and fabric configuration with a Fibre Channel switch. The possible use of the equipment for event building in the ATLAS DAQ prototype “−1” has been studied.
A project has been approved by the ATLAS Collaboration for the design and implementation of a Data Acquisition and Event Filter prototype, based on the functional architecture described in the ATLAS ...Technical Proposal. The prototype consists of a full “vertical” slice of the ATLAS Data Acquisition and Event Filter architecture, including all the hardware and software elements of the data flow, its control and monitoring as well as all the elements of a complete on-line system. This paper outlines the project, its goals, structure, schedule and current status and describes details of the system architecture and its components.
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