Author: White, G.R.
Paper Title Page
TUCAUST04 Changing Horses Mid-stream: Upgrading the LCLS Control System During Production Operations 574
  • S. L. Hoobler, R.P. Chestnut, S. Chevtsov, T.M. Himel, K.D. Kotturi, K. Luchini, J.J. Olsen, S. Peng, J. Rock, R.C. Sass, T. Straumann, R. Traller, G.R. White, S. Zelazny, J. Zhou
    SLAC, Menlo Park, California, USA
  The control system for the Linac Coherent Light Source (LCLS) began as a combination of new and legacy systems. When the LCLS began operating, the bulk of the facility was newly constructed, including a new control system using the Experimental Physics and Industrial Control System (EPICS) framework. The Linear Accelerator (LINAC) portion of the LCLS was repurposed for use by the LCLS and was controlled by the legacy system, which was built nearly 30 years ago. This system uses CAMAC, distributed 80386 microprocessors, and a central Alpha 6600 computer running the VMS operating system. This legacy control system has been successfully upgraded to EPICS during LCLS production operations while maintaining the 95% uptime required by the LCLS users. The successful transition was made possible by thorough testing in sections of the LINAC which were not in use by the LCLS. Additionally, a system was implemented to switch control of a LINAC section between new and legacy control systems in a few minutes. Using this rapid switching, testing could be performed during maintenance periods and accelerator development days. If any problems were encountered after a section had been switched to the new control system, it could be quickly switched back.  
slides icon Slides TUCAUST04 [0.183 MB]  
FRBHMULT06 EPICS V4 Expands Support to Physics Application, Data Acsuisition, and Data Analysis 1338
  • L.R. Dalesio, G. Carcassi, M.A. Davidsaver, M.R. Kraimer, R. Lange, N. Malitsky, G. Shen
    BNL, Upton, Long Island, New York, USA
  • T. Korhonen
    Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
  • J. Rowland
    Diamond, Oxfordshire, United Kingdom
  • M. Sekoranja
    Cosylab, Ljubljana, Slovenia
  • G.R. White
    SLAC, Menlo Park, California, USA
  Funding: Work supported under auspices of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886 with Brookhaven Science Associates, LLC, and in part by the DOE Contract DE-AC02-76SF00515
EPICS version 4 extends the functionality of version 3 by providing the ability to define, transport, and introspect composite data types. Version 3 provided a set of process variables and a data protocol that adequately defined scalar data along with an atomic set of attributes. While remaining backward compatible, Version 4 is able to easily expand this set with a data protocol capable of exchanging complex data types and parameterized data requests. Additionally, a group of engineers defined reference types for some applications in this environment. The goal of this work is to define a narrow interface with the minimal set of data types needed to support a distributed architecture for physics applications, data acquisition, and data analysis.
slides icon Slides FRBHMULT06 [0.188 MB]