The Application Research of PLC in Vacuum Constant Presses System

This paper introduces a set of equipment and its applications of the vacuum constant press system. The system is based on Siemens SIMATIC S7-120 PLC, revealed the actual pressure of tube net through the instruments, the pressure data is converted by instruments and appeared. At the same time, the converted data is transferred to the PLC through instruments, and the expected pressure value inner the tube net also can set or modify according to the actual situation, and realize the system control of making the actual pressure always around the expected value, and gradually reduce the extent of the fluctuations in order to achieve constant pressure control.