Exception Handling in a Flexible Cell Control System

Abstract An important aspect of modern manufacturing control systems is flexibility. A complication that must be considered when striving to achieve a completely flexible control system is the occurrence of faults. The structure of the control system must be such that new solutions to new error situations can be easily implemented into the existing structure. This paper presents a reference architecture of a manufacturing control system whose main feature is to provide flexibility. An important part in achieving this flexibility in the control system is the database implementation. The database is described with the help of an Entity Relationship model. The Entity-Relationship model is then extended to deal with error situations using a concept known as exception handling.