Plc Stepper Motor Controller

Abstract NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract Session 1559 PLC Stepper Motor Controller Leonard Sokoloff DeVRY Institute In this application PLC is used to control the operation of a stepper motor. Ladder Logic Diagram, the PLC program, uses step ladder instructions for implementation of the control algorithm. The motion control algorithm includes the control of stepper motor speed and direction of rotation. The stepper motor is a four phase permanent magnet type. The interface board is designed to generate appropriate voltage and current levels for each phase of the stepper motor. Darlington transistors with inductive kick protection are used for this purpose. The Programmable Logic Controller (PLC) is a relatively new technology that uses a computer to process the information. The control task is incorporated into a graphical program called the Ladder Logic Diagram. Any control task modifications are done by changing the program. This is why the use of the PLC is preferred to the traditional hard wired circuits in industrial controls. The traditional hard-wired control circuits are designed to perform a dedicated task. A temperature control board, for example, accepts its inputs from temperature sensors, processes these signals, and generates appropriate control signals to turn ON or OFF output devices such as heaters, fans, or air conditioners. All hard-wired circuits are generally very costly to design and build. If a circuit has to be modified, it must be torn apart and rewired, thus making modifications very costly. This application is part of an effort at DeVry to include into the curriculum important technologies such as the virtual instrumentation and the programmable logic controllers. The PLC Stepper Motor Controller is one of several projects that are being added to the upper trimester laboratory. 1