PLC (Programmable Logic Controller) is a kind of electronic equipment specially used for industrial automation control. It can control the output signal according to the preset program and input signal, and realize the automatic control of various devices and systems. In the street lamp control system, PLC can be used to realize the automatic switch and brightness level function of street lamps.

First of all, the design of PLC street lamp control system needs to consider the automatic switch function of street lamp. By sensing the brightness level of the surrounding environment through the sensor, PLC can judge whether the street lamp needs to be turned on or off according to the preset brightness threshold. When the ambient brightness is lower than the threshold, PLC will automatically turn on the street lamp; When the ambient brightness is higher than the threshold, PLC will automatically turn off the street lamp. This can realize the intelligent control of street lamps, save energy and improve the service life of street lamps.

Secondly, the PLC street lamp control system can also adjust the brightness of street lamps. By adjusting the voltage or current of the output signal, PLC can control the brightness of the street lamp. When the demand for low brightness is small at night, PLC can reduce the brightness of street lamps to save energy; When higher brightness is needed, PLC can improve the brightness of street lamps to provide better lighting effect. In this way, the brightness of the street lamp can be flexibly adjusted according to the actual demand, and the use efficiency of the street lamp can be improved.

In addition, the PLC street lamp control system can also realize the function of street lamp fault detection and alarm. PLC can judge whether the street lamp works normally by monitoring the working state, current and voltage of the street lamp. When the street lamp is found to be out of order, PLC can send an alarm signal to remind relevant personnel to carry out maintenance and treatment. This can find and solve the street lamp fault in time and ensure the normal operation of the street lamp.

To sum up, the design of street lamp control system based on PLC can realize the functions of automatic switch, brightness level, fault detection and alarm. Through intelligent control, the use efficiency and energy saving effect of street lamps can be improved, and the quality and reliability of urban lighting can be improved.