The Application Of Embedded System In Touch Human Machine Interface

With the development of automatic control technology, users'requirements of the control system are getting higher and higher. In order to facilitate users'operation and monitoring of the system, touch human machine interface, began to be used in the various fields of industrial control,it has become an important component of control systems. Touch human machine interface, its key function is to replace the traditional control panel and display meter, communication with the control unit (such as PLC, MCU), achieving the exchange of information which between human and control systems, more easily achieve the operation and monitoring of the whole system. Touch human machine interface, with its fast response, simple operation and high reliability, etc. It has been widely used in the field of industrial control.Now, there's a lot of industrial products, but because most of the products are imported or producted by Taiwan, the price is usually higher. Lower costs,directly to the user function and use own I/O can directly control the servo motor and inverter, can both communicate with PLC and MCU. This man-machine interface touch very rare in the industrial field. Based on the current situation, this issue presents a touch man-machine interface, which has its own characteristic, industrial grade and economical: with the basic functions of a general touch man-machine interface, but also satisfied with specific users for different requirements , either can combination with PLC or can combination with MCU system.The touch human machine interface is taken as a concrete research object. The application of mbedded system in touch human machine interface is realized by the co-design method of software and hardware, with the ARM series embedded processor as the core of hardware platform and based on ARM platform to complete the design of software platform.Firstly, the overview of touch human machine interface is introduced, the selection and characteristics of embedded processors. Then the hardware and software platforms are detailed introduced, including the core design system of LPC2136. The emphasis of this thesis is the design and realization of HMI's each part, including the detailed design of hardware circuit, as well as the design method involved in hardware circuit design of each module, and communications between touch human machine interface and the upper and lower-bit machine, etc. Finally, introduce the application of touch human machine interface in the actual program, and evaluate the actual level of the system objectively. The innovation of this topic is: First, the system is designed by signal acquisition circuit of touch-screen, do not use a special signal conversion chip of touch screen, full use of system resources, and simplify the hardware structure, and also reduce the cost of system. Second, due to no expanding the system memory, the space of system memory is limited, after analysis, the contradiction between the color of the diverse needs and limited space is finally settled. Third, using own I / O can directly control the servo motor and inverter, can both communication with PLC and MCU. It is the aim of this project to explore the application of touch human machine interface in the industrial control fields.The end of this thesis is the summary of the whole thesis and also point out the deficiencies in the existing system.