Proton Storage Ring Control System Upgrade
Interim Status

Michael A. Oothoudt, Eric A. Bjorklund, Stanley K. Brown
Norman T. Callaway, Gary P. Carr, L. Robert Dalesio
John A. Faucett, David P. Gurd, Margye P. Harrington
Jeffrey O. Hill, Debora M. Kerstiens, Andrew J. Kozubal
Matthew C. Needes, David J. Ostrem, Bobby A. Quintana
Stuart C. Schaller, Matthew W. Stettler, Michael E. Thuot
George D. Vaughn, David S. Warren, Robert E. Weiss
Rozelle M. Wright, Martha V. Zumbro

Los Alamos Neutron Science Center
Los Alamos National Laboratory
Los Alamos, New Mexico 87545


The original Proton Storage Ring control system was designed in the early 1980s using a centralized database with periodic migration of commands and data between central and remote computers. PDP-11 remote computers read data from serial CAMAC modules and migrated the data over serial CAMAC to the central computer. The operator interface was through touch panels on Lexidata display screens and dumb terminals. The central computer was upgraded over the years from a VAX-11/750 to a VAX 4000/300.

In 1994 a project was started to upgrade this control system. The new system is based on EPICS software and distributed architecture. Remote computers were replaced with Motorola 68040 monoboard computers in VME crates. The existing serial CAMAC hardware was used in most cases, but some modules were upgraded to Allen Bradley. The central computer and operator interface were replaced with Sun workstations.

At this time the old control system is approximately 75% replaced and a hybrid of the old and new systems is in continuous full Production use with high reliability. Over the next few months, the remainder of the old system will be replaced.

This paper will discuss the Upgrade experiences to date, strategies for replacing a highly reliable old system with a new system and possible future upgrade paths.