Life Cycle Support for PLC Controlled Manufacturing Systems

Abstract

Software support for PLC controlled manufacturing systems has focused primarily on the design and production phases of the control system lifecycle — there is limited support for the lifecycle of the manufacturing system itself. Also those phases of the system lifecycle after system development are poorly supported because effective support tools for these phases need to address both the control system and the manufacturing system. We believe that if a model of the total system is constructed at an early stage in the lifecycle which captures both the behaviour of the control system and the behaviour of the manufacturing system then the opportunity exists to develop a suite of model-based tools to support the lifecycle of a particular system from design onwards. We have tested this hypothesis by developing a methodology to enable models of PLC controlled manufacturing systems to be generated efficiently and constructing model-based software to assist in maintenance, diagnosis and system migration activities. We have also identified other activities within the lifecycle that would benefit from such software. The software that we have developed is in support of a 700 i / o point, 3 station assembly line.