The Isabelle Half-Cell Control System

The primary function of the ISABELLE half-cell control system is to monitor and control the magnet power supplies of the half-cell. In addition, the control system must be flexible enough that it can be expanded to become involved in additional areas such as vacuum and magnetic measurements. A control system based upon AGS control standards, but modified into a development tool for research and electrical engineering support has been constructed. Special attention was given to the inherent differences between controlling an ISABELLE and a conventional fast cycling accelerator. The use of FORTRAN and BASIC networks, and microprocessors is reviewed insofar as they pertain to this system. Some general opinions on model control systems, based upon our experience, will be presented. The half-cell is a full-scale model of an actual half-cell of the machine lattice of ISABELLE. A half-cell is composed of two dipole magnets and a quadrupole magnet. There are also multipole correction windings in the magnets for working line control. The primary function of the half-cell control system is to monitor and control the power supplies for these magnets.1 However, there are other services which the control system provides in addition. This article will review the development of the half-cell control system, emphasizing why certain decisions were reached. These were the managerial and technical criteria that most influenced the design. In October of 1975, a target date of January 1977 was set for the completion of a computer control system capable of controlling the power supplies of the half-cell.