Overview of Industrial-Control Displays
Industrial control display It is more convenient, fast and expressive, and can be simplified to Control program of PLC. The powerful touch screen creates a friendly human-machine interface. As a special computer peripheral, touch screen is the simplest and most natural way of human-computer interaction. It makes multimedia take on a new look and is a very attractive new multimedia interactive device.
Industrial display principle: Touch screen systems generally include touch screen controllers and touch detection devices. The main function of the touch screen controller is to receive the touch information control items of the touch point detection equipment owned by China, convert it into contact coordinates, and then send it to the CPU. At the same time, it can receive commands from the CPU and execute them. a
The touch detection device of the industrial control display is generally installed in the front of the display, and its main function is to detect the user's touch position and transmit it to the touch screen control card. Industrial display has strong flexibility, can replace or add functional modules according to design requirements, and has strong scalability.
Industrial control display It can meet the complex process control process, and can even be directly related to the network system PLC communication greatly facilitates the processing and transmission of control data and reduces the maintenance workload.
The inner surface of the industrial display is also coated with a transparent conductive layer, and there are many small (less than a thousandth of an inch) transparent isolation points between the two conductive layers. When a finger touches the screen, two conductive layers, usually insulated from each other, make contact at the point of contact. Since one of the conductive layers is connected to a uniform voltage field of 5V in the y-axis direction, the voltage of the sensing layer changes from zero to nonzero.
After the industrial control display controller detects this connection state, it performs A/D conversion, compares the obtained voltage value with 5V, and obtains the Y-axis and X-axis coordinates of the touch point, which is the most basic common principle of the all-resistive technology touch screen. The key to resistive touch screens is material technology. Depending on the number of touch screens, there are four wires.
The resistive touch screen of the industrial control display is coated with two layers on the surface of the reinforced glass OTI transparent metal oxide conductive layer. The outermost OTI coating is used as the conductor. Layer 5 OTI increases the voltage field from +0V to <>V horizontally and vertically through a precise network. The two OTI layers are separated by small transparent isolation points. When a finger touches the screen, a contact point appears in the two OTI conductive layers.
The computer simultaneously detects voltage and current and calculates the position of the touch. The reaction speed is 10-20ms, and the conductive layer of the five-wire resistive touch screen is made of nickel-gold plating material, which has good ductility. Due to the frequent contact of the outer conductive layer, the industrial display screen uses nickel-gold materials with good ductility to extend its service life, but the process cost is relatively high.
Although the nickel-gold conductive layer of industrial control display has good ductility, it can only be used as a transparent conductor. Due to its high conductivity, it is not suitable for the working surface of the resistive touch screen, and the metal thickness is not easy to achieve a very uniform thickness. It is not suitable for voltage distribution layers and can only be used as a probe layer.