Difference between man-machine interface and touch

2、 HMI product Q & A
1. What is the difference between man-machine interface and "touch screen"?
Strictly speaking, there are essential differences between the two. Because "touch screen" is only the hardware part that may be used in man-machine interface products. It is an input device installed in the front of the display screen instead of the functions of mouse and keyboard; The human-computer interface product is a kind of human-computer interaction equipment including hardware and software. In industry, man-machine interface products with touch input function are often called "touch screen", but this is unscientific.
2. What is the difference between man-machine interface and configuration software?
Human machine interface products are often called "touch screen", including HMI hardware and corresponding special screen configuration software. Generally, HMI hardware of different manufacturers use different screen configuration software, and the main equipment connected is PLC. Configuration software is a general tool software product running on PC hardware platform and windows operating system. It can also form HMI products together with PC or industrial control computer; There are many kinds of equipment supported by general configuration software, such as various PLC, PC board cards, instruments, frequency converters, modules and other equipment. Moreover, due to the strong performance of PC hardware platform (mainly reflected in speed and storage capacity), the function of general configuration software is also much stronger, which is suitable for large-scale monitoring system.
3. Is there an operating system in the HMI product?
Any man-machine interface product has a system software part. The system software runs in the processor of HMI and supports multi task processing function. A small operating system is required in the processor to manage the operation of system software. In the high-performance man-machine interface products based on tablet computers, general embedded operating systems such as wince and Linux are generally used.
4. Can the man-machine interface only be connected to PLC?
That's not the truth. Man machine interface products are produced to solve the man-machine interaction problem of PLC. However, with the development of computer technology and digital circuit technology, many industrial control equipment have the ability of serial port communication. Therefore, as long as industrial control equipment with serial port communication ability, such as frequency converter, DC governor, temperature control instrument, data acquisition module, etc., can be connected to man-machine interface products, To realize human-computer interaction.
5. Can the man-machine interface only be connected with other devices through the standard serial communication port?
Most of the time. However, with the development of computer and digital circuit technology, the interface ability of man-machine interface products is becoming stronger and stronger. In addition to the traditional serial (RS232, RS422 / RS485) communication interfaces, some man-machine interface products have data interfaces such as network port, parallel port and USB port. They can be connected with industrial control equipment with network port, parallel port and USB port to realize the man-machine interaction of the equipment.
6. Can the equipment with communication function be connected with man-machine interface products?
It should be. Because the common man-machine interface products provide a large number of common device communication drivers to choose from; Generally, as long as the communication driver corresponding to the connected equipment is selected in the screen configuration software of the human-computer interface, the communication connection between HMI and equipment can be completed. If there is no communication driver for the device to be connected in the configuration software of the selected HMI product, the user can inform the manufacturer of the HMI product of the communication port type and protocol content of the device to be connected, and ask the HMI manufacturer to prepare the communication driver for the device.
7. Can PC and touch screen communicate directly with PLC to complete HMI function?
Certainly. However, the corresponding HMI Software must be compiled to make the PC a real HMI product.
8. What is the development trend of man-machine interface in the future?
With the development of digital circuit and computer technology, the division of high, medium and low functions of future man-machine interface products will be less and less obvious, and the functions of HMI will be more and more abundant; HMI products above 5.7 inches will be all color display screens, and the service life of the screen will be longer. Due to the reduction of computer hardware cost, HMI products will focus on Tablet PC as high-end products of HMI hardware, because this high-end product has great advantages in processor speed, storage capacity, type and quantity of communication interfaces, networking ability and software resource sharing, which is the development direction of HMI products in the future. Of course, small-size (display size less than 5.7 inches) HMI products will be widely used in the human-computer interaction application of small mechanical equipment with the further enhancement of their functions (such as adding IO function) due to their advantages in volume and price.