1、 Action analysis

When a person approaches the automatic door, sensor X0 is turned on, and Y0 drives the motor to open the door at high speed. When it touches the door opening deceleration switch X1, it changes to low-speed opening. When the door opening limit switch X2 is touched, the motor stops running and starts to delay. If the sensor detects no one within 0.5 seconds, Y2 will start the motor and close the door at high speed. When encountering the door closing deceleration switch X4, switch to low-speed door closing, and when encountering the door closing limit switch X5, the motor stops running. If the sensor detects someone during the door closing period, the door will stop closing, and T1 will automatically switch to high-speed door opening after a delay of 0.5 seconds.

2、 Hardware Design

Based on the previous learning and the markings in the diagram, students can draw their own allocation of input and output ports, without further explanation

3、 Drawing of sequential functional diagrams

4、 Programming

1. Select sequence start stop circuit programming

2. Step instruction programming for selecting sequence structure