Application of Communication Optimization Strategy Based on Cascade PLC MODBUS in Fire Water System of Hydropower Station

As to the bad real-time problem of traditional communication scheme that is one master station and more slave stations' MODBUS communication in fire water system of hydropower station, in this paper, a connection scheme of a cascade PLC communication was proposed to solve the defects of decreasing transmission speed because of long distance in communication. The communication software of PLC was also optimized to reduce the cycle treatment time of PLC CPU, and greatly improve the communication efficiency and response speed. Practice shows that this scheme has high reference value and be worth to extend in the field of industrial control which use PLC MODBUS to communicate between one master station and more slave stations.