PLC Control System of the Stage Loader Based on Step Ladder Instruction

摘要

The purpose of this paper is to design an electric control system of stage loader which has clear logical relations and is easy to operate. The control system improves the working reliability of electric control system. Taking stage loader used in coal storage yard as an example, we introduce the mechanical structure and working principle of stage loader, mainly discussing about the components of electric control system, the action sequence of the actuator and electrical control PLC program. This paper pointes out that the use of step ladder instruction can make logical relations of action sequence clear and the use of state initialization instruction can make the state transitions among manual program, homing procedure and automatic continuous working procedure simple.