the upper computer uses monitoring software to write Chinese characters into the PLC, and the touch screen reads the corresponding Chinese characters from the PLC and displays them on the touch screen.
The upper computer is directly connected with the touch screen by Modbus Ethernet or serial port, and the touch screen is used as a slave station, and the upper software writes the character information into the touched variable and displays it. Because the touch screen supports multi-protocol communication at the same time, it does not affect the communication with PLC.