The touch screen is actually called a human-machine interface and is a human-machine control method that can communicate with the control device. Imagine a collection of button indicator lights. To understand the working principle of the touch screen, we must know the communication. We know that a button must control the transmission of an electrical signal, that is, the amount of switching. The touch screen controls a contactor, it must do it through a controller, such as "PLC". Firstly, the touch screen must know the device to be controlled, that is, the communication protocol of the controller must be available, such as MODBUS, PROFIBUS, CAN, etc. In the normal case the touch screen has the communication protocol of the PLC, I (the touch screen) tells you (PLC) that you close M0.0, you (PLC) can correctly recognize the command interpretation, and then execute!
The process is to install the configuration software of the touch screen on the PC (that is, the computer) (the configuration software corresponding to the screen of each brand is also different), open the software configuration, start the configuration, that is, draw the picture, and define the address of the connection (this address is the one of the internal components of the PLC, such as Siemens I, Q, V, T, C, Mitsubishi X, Y, M, etc. Before the screen is done, it is best to list the points that the PLC need the touch screen to control), of course, the prerequisite is to define the communication protocol with which to communicate, that is, to define the type of PLC. (So before you buy the touch screen, you must refer to the sample to know if it supports the PLC controller you want to use.) After the configuration is completed, download it to the touch screen (the way used by different manufacturers is different, some are USB downloads, some are 232, some are 485), download After the completion, connect the touch screen to the PLC with the cable to control the PLC action!