Current electronic products generally consist of two parts: hardware and software. The hardware part includes a processor, a display unit, an input unit, a communication interface, and a data storage unit. The software part is generally divided into two parts, namely the system software running in the HMI hardware and the screen configuration software running in the PC Windows operating system. This episode would like to introduce 8 basic knowledge of HMI in detail.

Human Machine Interaction, also known as: touch screen, HMI.

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

(1) Basic functions:

Equipment working status display, such as indicator lights, buttons, text, graphics, curves, etc.;

Data and text input operation, print output;

Production formula storage, equipment production data record;

Simple logic and numerical calculations;

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

(2) Selection index:

Display screen dimesion and color, resolution;

HMI processor speed performance;

Input method-touch screen or membrane keyboard;

Screen storage capacity-whether the unit of capacity is byte or bit;

Types and quantities of communication ports, whether they support printing functions, etc.

(3) Product classification:

Primary product: membrane key input type, the display size is usually less than six inches

Intermediate product: touch screen input type, the display size is usually larger than six inches

Advanced products: computer input type, display size usually larger than ten inches.

2. General use steps of human-machine interface

(1) Determine the task requirements and select suitable HMI products;

(2) Edit the "project file" with the screen configuration software on the PC;

(3) Test and save the edited "project file";

(4) Connect the PC to the HMI hardware, and download the "project file" to the HMI;

(5) Connect HMI and industrial controller (such as PLC, instrument, etc.) to realize human-machine interaction.

3. What is the difference between the man-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 human-machine interface products, it is an input device that replaces the mouse and keyboard functions and is installed in the front of the display screen.

The human-machine interface product is a human-computer interaction device that includes hardware and software. In the industry, people often call man-machine interface products with touch input functions "touch screens", but this is unscientific.

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

Human-machine interface products, often called "touch screens", include HMI hardware and corresponding dedicated screen configuration software. Generally, HMI hardware of different manufacturers uses different screen configuration software, and the main type of connected equipment is PLC .

Configuration software is a general tool software product running on PC hardware platform and windows operating system. It can also form HMI product together with PC or industrial computer. There are many types of equipment supported by the general configuration software, such as various PLCs, PC boards, meters, inverters, modules and other equipment. Due to the powerful performance of the PC hardware platform (mainly reflected in the speed and storage capacity), the general configuration software is also much more powerful, suitable for large-scale monitoring systems.

5. Is there an operating system in the human-machine interface product?

Any man-machine interface product has a system software part. The system software runs in the HMI processor and supports multitasking. The processor needs a small operating system to manage the running of the system software. In 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 human-machine interface only be connected to PLC?

Human-machine interface products are produced to solve the human-computer interaction problem of PLC, but with the development of computer technology and digital circuit technology, many industrial control equipment have serial communication capabilities. Therefore, as long as industrial control equipment with serial communication capabilities, such as inverters, DC speed regulators, temperature control instruments, data acquisition modules, etc., can be connected to human-machine interface products to realize human-computer interaction.

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

With the development of computer and digital circuit technology, the interface capabilities of man-machine interface products are getting stronger and stronger. In addition to the traditional serial (RS232, RS422/RS485) communication interfaces, many human-machine interface products already have data interfaces such as network ports, parallel ports, and USB ports. The control equipment is connected to realize the human-machine interaction of the equipment.

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

With the development of digital circuits and computer technology, the functions of HMI will become more and more abundant. More than 5.7-inch HMI products will use more color displays, and the screen life will be longer.

Due to the reduction of computer hardware costs, HMI products will be based on high-end products with tablet PC computers as HMI hardware. Because this high-end product has greater advantages in terms of processor speed, storage capacity, type and quantity of communication interfaces, networking capabilities, and software resource sharing, it is the future development direction of HMI products. Of course, small-size (display size less than 5.7 inches) HMI products, due to their advantages in size and price, as their functions are further enhanced (such as the addition of IO functions), they will be used in the human-computer interaction of small mechanical equipment It is widely used in applications.

The machinery industry, such as machine tool, textile machinery, electronic equipment and other industries, are relatively mature industries. In the long run, there is still a need for equipment upgrades in these industries. In this process of upgrading, some small manufacturers that have been using relatively low-end products will be eliminated. Many companies will look for equipment suppliers that can meet their development plans and help them improve their productivity during the equipment update process.

In view of this demand, future changes in the human-computer interface will change in shape, concept, application occasions, etc., which will bring about revolutions in the core technology of industrial computers. Generally speaking, the future development trend of human-machine interface is five modernizations: platform embedding, equipment intelligence, interface fashion, communication network and energy saving and environmental protection.