Process Control for the ISABELLE System

A low cost, highly reliable control system has been developed for use in the radiation environment of the ISABELLE ring. The Ultra-High Vacuum installation will consist of approximately 1500 stations - each having 8 readbacks, 4 on-off operations and 4 special functions - distributed over 2.5 miles. The paper will describe a multidrop party line system in which a pp based controller located in a protected environment communicates with up to 25 vacuum stations. All the μm controllers will be linked via the ISABELLE data highway. Mechanical, electronic and software aspects of the system are discussed and performance data from our First Cell model is presented.