Author: Gorbonosov, R.
Paper Title Page
MOPMN027 The LHC Sequencer 300
  • R. Alemany-Fernandez, V. Baggiolini, R. Gorbonosov, D. Khasbulatov, M. Lamont, P. Le Roux, C. Roderick
    CERN, Geneva, Switzerland
  The Large Hadron Collider (LHC) at CERN is a highly complex system made of many different sub-systems whose operation implies the execution of many tasks with stringent constraints on the order and duration of the execution. To be able to operate such a system in the most efficient and reliable way the operators in the CERN control room use a high level control system: the LHC Sequencer. The LHC Sequencer system is composed of several components, including an Oracle database where operational sequences are configured, a core server that orchestrates the execution of the sequences, and two graphical user interfaces: one for sequence edition, and another for sequence execution. This paper describes the architecture of the LHC Sequencer system, and how the sequences are prepared and used for LHC operation.  
poster icon Poster MOPMN027 [2.163 MB]  
WEPMS007 Backward Compatibility as a Key Measure for Smooth Upgrades to the LHC Control System 989
  • V. Baggiolini, M. Arruat, D. Csikos, R. Gorbonosov, P. Tarasenko, Z. Zaharieva
    CERN, Geneva, Switzerland
  Now that the LHC is operational, a big challenge is to upgrade the control system smoothly, with minimal downtime and interruptions. Backward compatibility (BC) is a key measure to achieve this: a subsystem with a stable API can be upgraded smoothly. As part of a broader Quality Assurance effort, the CERN Accelerator Controls group explored methods and tools supporting BC. We investigated two aspects in particular: (1) "Incoming dependencies", to know which part of an API is really used by clients and (2) BC validation, to check that a modification is really backward compatible. We used this approach for Java APIs and for FESA devices (which expose an API in the form of device/property sets). For Java APIs, we gather dependency information by regularly running byte-code analysis on all the 1000 Jar files that belong to the control system and find incoming dependencies (methods calls and inheritance). An Eclipse plug-in we developed shows these incoming dependencies to the developer. If an API method is used by many clients, it has to remain backward compatible. On the other hand, if a method is not used, it can be freely modified. To validate BC, we are exploring the official Eclipse tools (PDE-API tools), and others that check BC without need for invasive technology such as OSGi. For FESA devices, we instrumented key components of our controls system to know which devices and properties are in use. This information is collected in the Controls Database and is used (amongst others) by the FESA design tools in order to prevent the FESA class developer from breaking BC.  
WEPMU011 Automatic Injection Quality Checks for the LHC 1077
  • L.N. Drosdal, B. Goddard, R. Gorbonosov, S. Jackson, D. Jacquet, V. Kain, D. Khasbulatov, M. Misiowiec, J. Wenninger, C. Zamantzas
    CERN, Geneva, Switzerland
  Twelve injections per beam are required to fill the LHC with the nominal filling scheme. The injected beam needs to fulfill a number of requirements to provide useful physics for the experiments when they take data at collisions later on in the LHC cycle. These requirements are checked by a dedicated software system, called the LHC injection quality check. At each injection, this system receives data about beam characteristics from key equipment in the LHC and analyzes it online to determine the quality of the injected beam after each injection. If the quality is insufficient, the automatic injection process is stopped, and the operator has to take corrective measures. This paper will describe the software architecture of the LHC injection quality check and the interplay with other systems. A set of tools for self-monitoring of the injection quality checks to achieve optimum performance will be discussed as well. Results obtained during the LHC commissioning year 2010 and the LHC run 2011 will finally be presented.  
poster icon Poster WEPMU011 [0.358 MB]  
WEPMU023 External Post-Operational Checks for the LHC Beam Dumping System 1111
  • N. Magnin, V. Baggiolini, E. Carlier, B. Goddard, R. Gorbonosov, D. Khasbulatov, J.A. Uythoven, M. Zerlauth
    CERN, Geneva, Switzerland
  The LHC Beam Dumping System (LBDS) is a critical part of the LHC machine protection system. After every LHC beam dump action the various signals and transient data recordings of the beam dumping control systems and beam instrumentation measurements are automatically analysed by the eXternal Post-Operational Checks (XPOC) system to verify the correct execution of the dump action and the integrity of the related equipment. This software system complements the LHC machine protection hardware, and has to ascertain that the beam dumping system is ‘as good as new’ before the start of the next operational cycle. This is the only way by which the stringent reliability requirements can be met. The XPOC system has been developed within the framework of the LHC “Post-Mortem” system, allowing highly dependable data acquisition, data archiving, live analysis of acquired data and replay of previously recorded events. It is composed of various analysis modules, each one dedicated to the analysis of measurements coming from specific equipment. This paper describes the global architecture of the XPOC system and gives examples of the analyses performed by some of the most important analysis modules. It explains the integration of the XPOC into the LHC control infrastructure along with its integration into the decision chain to allow proceeding with beam operation. Finally, it discusses the operational experience with the XPOC system acquired during the first years of LHC operation, and illustrates examples of internal system faults or abnormal beam dump executions which it has detected.  
poster icon Poster WEPMU023 [1.768 MB]