Integration of VICbus, FDL, SCI and Ethernet in the CERN CASCADE data acquisition system

Cascade is a multi-processor real-time data-acquisition system for HEP experiments developed at CERN by the ECP-DS group. Configurations supported today include VMEbus processors running OS-9 and UNIX workstations. The CASCADE data acquisition processes, called stages communicate via links, at present VICbus between VME crates and Ethernet between VMEbus processors and workstations. Work is in progress to introduce new inter-stage links based on the Fast Data Link between VME crates and on SCI for data exchange between SUN stations. The paper gives a short description of the architecture of CASCADE with emphasis on the link aspects. The implementation and current status of the inter-stage links based on VICbus, Ethernet, FDI, and SCI will be described and results on the performances presented

Review and prospects of the CASCADE data acquisition system at CERN

CASCADE, a multi-processor real-time data-acquisition system for HEP experiments developed at CERN by the ECP-DS group, has now been in operation for one year. The current implementation supports configurations based on VMEbus processors running OS-9 and on UNIX workstations interconnected via VICbus or Ethernet. The project is reviewed by describing the main characteristics of the package, the applications in which it has been used, and the results of this experience. The main improvements of 1994, which include a parameterized multi-level event builder, a remote monitoring option and a powerful run control facility, as well as ongoing developments and prospects for 1995, are presented

The ROD crate DAQ software framework of the ATLAS data acquisition system

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

The ATLAS Readout System for LHC Runs 2 and 3

The ReadOut System (ROS) is a central part of the data acquisition (DAQ) system of the ATLAS Experiment at the CERN Large Hadron Collider (LHC). The system is responsible for receiving and buffering event data from all detector subsystems and serving these to the High Level Trigger (HLT) system via a 10 GbE network, discarding or transporting data onward once the trigger has completed its selection process. The ATLAS ROS was completely replaced during the 2013-2014 experimental shutdown in order to meet the demanding conditions expected during LHC Run 2 and Run 3 (2015-2025). The ROS consists of roughly one hundred Linux-based 2U-high rack-mounted servers equipped with PCIe I/O cards and 10 GbE interfaces. This paper documents the system requirements for LHC Runs 2 and 3 and the design choices taken to meet them. The results of performance measurements and the re-use of ROS technology for the development of data sources, test platforms for other systems, and another ATLAS DAQ system component, namely the Region of Interest Builder (RoIB), are also discussed. Finally performance results for Run 2 operations are presented before looking at the upgrade for Run 3.Comment: 40 pages, 18 figures, journal pape

Experience with fibre channel in the environment of the ATLAS DAQ protoype "-1" project

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 PwerPC-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 Ch annel switch. The possible used of the equipment for event building in the ATLAS DAQ prototype "-1" has been studied

Using Linux PCs in DAQ applications

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. (18 refs)

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30