Design of full automatic irrigation control system based on PLC
Huifeng Jiang · 2004
The application of programmable logic controller (PLC) in water-saving irrigation control system is introduced. The system is designed with manual irrigation mode by which the irrigation order and time for various irrigation areas can be set according to user's demand. The system is also designed with automatic irrigation mode by which the soil moisture measured with sensor is inputted to PLC and compared with the optimal water content of soil by the program in PLC, then the electrical motor is put into or out of operation, and the electromagnetic valves are opened or closed based on the comparison. In order to reduce the start-up current of electrical motor of water pump, alleviate the impact on power net and reduce energy consumption, Y/Δ start is adopt.