The wiring method of the plc buzzer is as follows:
1. The buzzer signal is connected to the ground and the signal is connected. The circuit design adopts direct connection to the positive, and the transistor is connected to the control ground.
2. Confirm the positive and negative of the buzzer. The new long leg is positive and the short leg is negative. The voltage limit of the buzzer, select 5V voltage for the buzzer.
3. The sound of the buzzer is mainly related to parameters, including high decibels and low decibels. The I/O port output is connected to the base of the PNP transistor through a 4.7k resistor.