The common sense of human-machine interface is the first knowledge for beginners. The product consists of hardware and software. The hardware part includes processor, display unit, input unit, communication interface, data storage unit, etc. HMI software is generally divided into two parts. It is two parts, namely the system software running in the HMI hardware and the screen configuration software running under the Windows operating system of the PC. This article gives you a detailed introduction to the 10 common senses of the human-machine interface.

 

1. Basic functions and selection indicators of human-machine interface products

basic skills:

Device working status display, such as indicators, buttons, text, graphics, curves, etc.;

Data, text input operation, printout;

Production recipe storage, equipment production data record;

Simple logic and numerical operations;

Can be connected to a variety of industrial control equipment networking.

Selection indicator:

Display size and color, resolution;

HMI processor speed performance;

Input method: touch screen or membrane keyboard;

Screen storage capacity, note that the unit of capacity indicated by the manufacturer is byte (byte) or bit (bit);

Whether the type and number of communication ports support printing.

2. Classification of man-machine interface

The HMI of the membrane key input has a display size of less than 5.7′, and the screen configuration software is free, which is a primary product. Such as POP-HMI small human machine interface;

The HMI of the touch screen input, the screen size is 5.7’~12.1′, the screen configuration software is free, and it is a mid-level product;

Based on the tablet PC computer, a variety of communication ports, high-performance HMI, display size is greater than 10.4′, screen configuration software charges, is a high-end product.

3. What is the difference between the human-machine interface and the “touch screen” that people often say?

Strictly speaking, there is a fundamental difference between the two. Because the “touch screen” is only the hardware part that may be used in the human-machine interface product, it is an input device that is installed on the front end of the display instead of the mouse and keyboard part function; and the human-machine interface product is a kind of hardware and software. Human-computer interaction device. In the industry, people who have touch input functions are often referred to as “touch screens”, but this is unscientific.

4. What is the difference between the man-machine interface and the configuration software?

Man-machine interface products, often referred to as “touch screen”, contain HMI hardware and corresponding dedicated screen configuration software. Under normal circumstances, different manufacturers’ HMI hardware uses different screen configuration software, and the main equipment type connected is PLC. . The configuration software is a general-purpose tool software product running on the PC hardware platform and the Windows operating system. It can also be combined with a PC or an industrial computer to form an HMI product. The general configuration software supports a wide variety of devices, such as various types. PLC, PC board, instrument, inverter, module and other equipment, and because of the powerful performance of the PC hardware platform (mainly in the speed and storage capacity), the general configuration software is also much more powerful, suitable for large-scale monitoring In the system.

5. Is there an operating system in the HMI product?

Any human interface product has a system software part. The system software runs in the HMI processor and supports multi-tasking. The processor needs to run a small operating system management system software. In the high-performance human-machine interface products based on tablet computers, general-purpose embedded operating systems such as WinCE and Linux are generally used.

6. Can the man-machine interface only be connected to the PLC?

not like this. Human-machine interface products are produced to solve the human-computer interaction problem of PLC. However, with the development of computer technology and digital circuit technology, many industrial control devices have serial communication capabilities, so industrial control equipment with serial communication capability is only needed. For example, inverters, DC governors, temperature control instruments, and digital acquisition modules can be connected to human-machine interface products to realize human-computer interaction functions.

7. Can the man-machine interface be connected to other devices through a standard serial communication port?

This is the case in most cases. However, with the development of computer and digital circuit technology, the interface capability of human-machine interface products is getting stronger and stronger. In addition to the traditional serial (RS232, RS422/RS485) communication interface, some human-machine interface products already have data interfaces such as network port, parallel port and USB port, which can be used in industries with interfaces such as network port, parallel port and USB port. Control devices are connected to implement human-machine interaction of the devices.

8. Is there a device with communication function that can be connected to the HMI product?

It should be like this. Because the universal human-machine interface products provide a large number of common device communication drivers to be selected; in general, as long as the communication driver corresponding to the connected device is selected in the screen configuration software of the human-machine interface, The communication connection between the HMI and the device can be completed. If there is no communication driver to connect the device in the configuration software of the selected HMI product, the user can inform the manufacturer of the HMI product of the type of communication port and protocol to be connected to the device, and ask the HMI manufacturer to compile the communication driver of the device. program.

9, PC plus touch screen, can communicate directly with the PLC, complete the HMI function?

of course can. However, the corresponding HMI software must be compiled to make the PC a true HMI product.

10. What is the future development trend of human-machine interface?

With the development of digital circuits and computer technology, the future high-, medium-, and low-level division of human-machine interface products will become less and less obvious, and the functions of HMI will become more and more abundant; HMI products of 5.7 inches or more will be all It is a color display and the life of the screen will be longer. Due to the reduction in computer hardware costs, HMI products will be based on tablet PCs as high-end products for HMI hardware, because of the high-end products in terms of processor speed, storage capacity, type and number of communication interfaces, networking capabilities, and software resource sharing. Both have great advantages and are the development direction of future HMI products. Of course, small-sized (display size less than 5.7-inch) HMI products, due to their advantages in size and price, with further enhancements (such as increased IO functionality), will be used in human-computer interaction applications for small mechanical devices. Widely used.

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