Design and Implement of Automatic Control System of the Campus Ringer

According to the control requirements of campus ringers, a PLC-based automatic control system is realized by using the real time clock function provided by S7-200 CPU224 PLC and the friendly human-computer interaction function provided by TD400 text display. The control system can automatically judge the ringing work mode by the current system time of PLC, that is the summer time ringing mode and the winter time ringing mode. The user can also choose other work modes, such as the college English test mode and the computer grade test mode by pushing the button of the text display. In this paper the composition of the control system, the working principle and the designs of hardware and software are introduced. The system has advantages of friendly interface, simple operation, convenient maintenance, high reliability, strong anti interference ability, which makes it popularize.