Using UML as Front-End for PLC Program Design

To minimize the influence of experiential factor and guarantee the software quality from the design phase, with the aid of unified modeling language (UML), an object-oriented design method for PLC program is presented. With UML as design tool, class diagram and state machine diagram are chosen respectively to describe the static structure and dynamic behavior of the PLC based control system, and PLC ladder diagram is acquired from state machine diagram subsequently. With the combination of object-oriented technology, UML and classic PLC design technology, the software reliability of PLC based control system is promoted, and the application area of object-oriented technology and UML is extended.