General knowledge of human-machine interface is for beginners is the first to understand the knowledge, the product consists of two parts of the hardware and software, the hardware part of the processor, display units, input units, communication interfaces, data storage units, etc. HMI software is generally divided into two parts, that is, running on the HMI hardware in the system software and running on the PC under the Windows operating system screen configuration software. This article provides a detailed introduction to the 10 general knowledge of the human-machine interface.
First, the basic functions of human-machine interface products and selection indicators
(1) Basic functions:
Equipment working status display, such as indicators, buttons, text, graphics, curves and so on;
Data, text input operation, printout;
Production formula storage, equipment production data records;
Simple logic and numerical operations;
Can be connected to a variety of industrial control equipment networking.
(2) Selection indicators:
Display size and color, resolution;
Processor speed performance of HMI;
Input method-touch screen or membrane keyboard;
Screen storage capacity - capacity unit is byte, or bit;
Type and number of communication ports, whether to support the print function, etc..
(3) Product classification:
Primary products: membrane key input type, display size is usually less than six inches
Intermediate products: touch-screen input type, display size is usually larger than six inches.
Advanced products: computer input type, display size is usually larger than ten inches.
Second, the routine use of HMI steps
(1) Clearly monitor the task requirements, select the appropriate HMI products;
(2) Edit the "project file" with the screen configuration software on the PC;
(3) Test and save the edited "project file";
(4) PC connected to the HMI hardware, download the "project file" to the HMI;
(5) Connect HMI and industrial controllers (such as PLC, instrumentation, etc.) to achieve human-computer interaction.
Third, what is the difference between the human-machine interface and what is often called "touch screen"?
Strictly speaking, the two are fundamentally different. Because the "touch screen" is only a human-machine interface products may be used in the hardware part, is an alternative to the mouse and keyboard part of the function, installed in the front of the display of the input device.
Human-machine interface product is a kind of human-machine interaction equipment which contains hardware and software. In the industry, people often have touch input function of human-machine interface products called "touch screen", but this is not scientific.
Fourth, what is the difference between HMI and configuration software?
HMI products, often referred to as "touch screen", including HMI hardware and the corresponding special screen configuration software, in general, different manufacturers of HMI hardware to use different screen configuration software, connected to the main types of equipment is PLC.
Configuration software is running on the PC hardware platform, windows operating system under a common tool software products, and PC or industrial control machine can also be composed of HMI products; general configuration software to support a very wide range of devices, such as a variety of PLCs, PC boards, meters, inverters, modules and other devices, and because of the PC's hardware platform with strong performance (mainly reacting to speed and storage capacity), general configuration software. And because of the strong performance of the hardware platform of PC (mainly in the speed and storage capacity), the function of the general configuration software is also much stronger, which is suitable for the large-scale monitoring system.
V. Is there any operating system in HMI products?
Any HMI product has a system software part, the system software runs in the processor of HMI, supporting multi-tasking function, the processor needs to have a small operating system to manage the operation of the system software. Tablet PC-based high-performance HMI products, generally use WinCE, Linux and other general-purpose embedded operating systems.
Sixth, the human-machine interface can only be connected to the PLC?
Not so. HMI products are designed to solve the PLC human-computer interaction problems arising, but with the development of computer technology and digital circuit technology, a lot of industrial control equipment are equipped with serial communication capabilities, so as long as there is a serial communication capabilities of industrial control equipment, such as frequency converters, DC speed controllers, temperature control instrumentation, digital acquisition module, etc. can be connected to the HMI products to realize the human-computer interaction function.
Seven, the HMI can only be connected to other devices through the standard serial communication port?
No, this is not the case. But with the development of computer and digital circuit technology, the interface capability of HMI products is getting stronger and stronger. In addition to the traditional serial (RS232, RS422 / RS485) communication interface, many human-machine interface products have a network port, parallel port, USB port and other data interfaces, they can have a network port, parallel port, USB port and other interfaces connected to industrial control equipment to achieve the interaction of the equipment man-machine.
Eight, is there a communication function of the device must be able to connect with the human-machine interface products?
This should be the case. Because the general HMI products provide a large number of commonly used equipment available for selection of communication drivers; in general, as long as the screen configuration software in the HMI interface to select and connect to the device corresponding to the communication driver, you can complete the HMI and equipment communication connection. If the configuration software of the selected HMI product does not have a communication driver for the device to be connected, the user can inform the manufacturer of the HMI product of the type of the communication port and the protocol content of the device to be connected, and ask the HMI manufacturer to prepare a communication driver for the device on behalf of the manufacturer.
Nine, PC plus display, can directly communicate with the PLC to complete the HMI function?
Of course. However, the PC must also prepare the corresponding configuration software, in order to make the PC become a real HMI products.
X. What is the future development trend of HMI?
With the development of digital circuits and computer technology, the future of HMI products in the function of high, medium and low division will be less and less obvious, HMI functions will be more and more rich; 5.7 inches above the HMI product will be all color display, screen life will be longer.
Due to the reduction in the cost of computer hardware, HMI products will be flat-panel PC computers for HMI hardware for high-end products, because this high-end products in the processor speed, storage capacity, the type and number of communication interfaces, networking capabilities, software resource sharing have a greater advantage in the future direction of development of HMI products. Of course, the small size (display size less than 5.7 inches) HMI products, due to its advantages in size and price, with the further enhancement of its functionality (such as increasing the IO function), will be widely used in small machinery and equipment for human-computer interaction applications.
Some mechanical industries, such as machine tools, textile machinery, electronic equipment and other industries, has been developed in the country for decades, relatively speaking, belongs to a more mature industry, in the long run, these industries also exist in the demand for upgrading equipment. In this upgrading process, it is true that there will be some small, has been using relatively low-end products manufacturers were eliminated, but there are also many companies in the process of equipment renewal, the demand will be repositioned to look for those who are able to meet their development plans, to help them improve their own productivity of the equipment suppliers.
In view of this demand, the future of the human-machine interface will change in shape, concepts, applications and other aspects of the change, which will bring about a change in the core technology of industrial control machines. In general, the future development trend of human-machine interface is six modernization: platform embedded, brand nationalization, equipment intelligence, interface fashion, communication network and energy saving and environmental protection.