Author: Olsen, J.J.
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]  
FRAAUST01 Development of the Machine Protection System for LCLS-I 1281
  • J.E. Dusatko, M. Boyes, P. Krejcik, S.R. Norum, J.J. Olsen
    SLAC, Menlo Park, California, USA
  Funding: U.S. Department of Energy under Contract Nos. DE-AC02-06CH11357 and DE-AC02-76SF00515
Machine Protection System (MPS) requirements for the Linac Coherent Light Source I demand that fault detection and mitigation occur within one machine pulse (1/120th of a second at full beam rate). The MPS must handle inputs from a variety of sources including loss monitors as well as standard state-type inputs. These sensors exist at various places across the full 2.2km length of the machine. A new MPS has been developed based on a distributed star network where custom-designed local hardware nodes handle sensor inputs and mitigation outputs for localized regions of the LCLS accelerator complex. These Link-Nodes report status information and receive action commands from a centralized processor running the MPS algorithm over a private network. The individual Link-Node is a 3u chassis with configurable hardware components that can be setup with digital and analog inputs and outputs, depending upon the sensor and actuator requirements. Features include a custom MPS digital input/output subsystem, a private Ethernet interface, an embedded processor, a custom MPS engine implemented in an FPGA and an Industry Pack (IP) bus interface, allowing COTS and custom analog/digital I/O modules to be utilized for MPS functions. These features, while capable of handing standard MPS state-type inputs and outputs, allow other systems like beam loss monitors to be completely integrated within them. To date, four different types of Link-Nodes are in use in LCLS-I. This paper describes the design, construction and implementation of the LCLS MPS with a focus in the Link-Node.
slides icon Slides FRAAUST01 [3.573 MB]