Using basic Statechart to program industrial controllers

Despite the many studies that have attempted to develop "friendly" methods for industrial controller programming, they are still programmed by conventional "trial-and-error" methods and in practice, there is little written documentation on these systems. The ideal solution is to use a computational environment that allows industrial engineers to implement the system using high-level language and that follows international standards. Accordingly, this paper proposes a methodology to model and validate control programs for manufacturing systems that include sequential, parallel and timed operations, using a formalism based on Statecharts, denominated Basic Statechart (BSC). To improve the formal aspects of the original Statecharts, we introduce the semantic of the BSC using only characteristics relevant to the industrial area. We also present an algorithm that translates the control model described in BSC into Ladder diagrams, thereby enabling tests with actual PLCs. Finally, one typical example of application in the manufacturing area is discussed as case study to illustrate the proposed methodology. (C) 2011 Elsevier B.V. All rights reserved.