What is HMI

HMI is short for Human Machine Interface. The man-machine interface (also known as a user interface or user interface) is the medium for the interaction and information exchange between the system and users. It realizes the transformation between the internal form of information and the form acceptable to human beings. The human-machine interface exists in all fields involved in human-machine information exchange.

There are many types of HMI interfaces, including RS232, RS485, RJ45.

HMI Interface HMI interface common sense

1. The definition of human-machine interface products connecting programmable controller (PLC), inverter, dc speed regulator, instrumentation, industrial control equipment, the use of screen display, through the input unit (such as screen, keyboard, mouse, etc.) parameters or input commands written work, realize the information interaction of digital human and machine equipment, composed of two parts of hardware and software.

2. Composition and working principle of HMI products. HMI products are composed of hardware and HMI software. The hardware includes a processor, display unit, input unit, communication interface, data storage unit, etc. The performance of the processor determines the performance of HMI products and is the core unit of HMI. Depending on the HMI product class, processors can be 8-bit, 16-bit, or 32-bit.HMI software is generally divided into two parts, namely system software running in HMI hardware and screen configuration software running in PC Windows operating system (such as JB-HMI screen configuration software). Users must first create “engineering files” using HMI’s screen configuration software, and then download the “engineering files” to the HMI processor through the SERIAL communication ports of the PC and HMI products.

3. Basic functions and selection indexes of human-machine interface products

Basic functions:

  • Display the working status of the equipment, such as indicator lights, buttons, text, graphics, curves, etc
  • Data, text input operation, printout
  • Storage of production formula and recording of equipment production data
  • Simple logical and numerical operations
  • Can connect a variety of industrial control equipment network

Selection index:

  • Screen size, color, and resolution
  • HMI processor speed performance

Input mode:

  • Touch screen or film keyboard

Screen storage capacity, note whether the manufacturer’s capacity unit is byte orbit

Type and quantity of communication port, whether it supports the printing function

4. Classification of human-machine interface products

The HMI film key input, the HMI display size is less than 5.7 ˊ, screen configuration software for free belongs to the primary products. Such as pop-HMI small man-machine interface

The HMI touch screen input, screen size is 5.7 12.1 ˊ ˊ ~, the picture configuration software for free, belongs to the intermediate products

Based on a tablet PC computer, a variety of communication, high-performance, HMI display size greater than 10.4 ˊ, screen configuration software to collect fees, belong to high-end products

5. Man-machine interface usage

Define monitoring task requirements and select suitable HMI products

Edit “Project File” with picture configuration software on PC

Test and save the edited Project file

The PC connects to the HMI hardware and downloads the “project file” into the HMI

Connect HMI and industrial controllers (such as PLC, instrument, etc.) to realize man-machine interaction

HMI interface product background

All high-efficiency HMI features a variety of features:

  • Multiple choices
  • Competitive prices
  • Reliable, efficient, intelligent hardware and a strong case
  • Animation editing is diverse
  • High-resolution graphics
  • C language program design is adopted
  • Stainless steel front frame is optional above panel 7″
  • IP 66K protection level
  • Suitable for harsh environments

HMI Product Q&A

1. What is the difference between the human-computer interface and what is often called “touch screen”?

Strictly speaking, there is an essential difference between the two. Because “touch screen” is only the hardware part that may be used in human-computer interface products, and it is an input device installed in the front of the display screen to replace some functions of mouse and keyboard. The human-computer interface product is a human-computer interaction device that includes hardware and software. In the industry, people often call the man-machine interface product with touch input function “touch screen”, but this is not scientific.

2. What is the difference between HMI and configuration software?

Man-machine interface products often referred to as “touch screen”, contain HMI hardware and corresponding special screen configuration software. In general, different manufacturers of HMI hardware use different screen configuration software, and the main type of equipment connected is PLC. Configuration software is a general tool software product running on the PC hardware platform and Windows operating system, and it can also constitute HMI products together with PC or INDUSTRIAL computer. The general configuration software supports many kinds of equipment, such as various PLC, PC board cards, instruments, inverter, modules, and other equipment. Moreover, due to the strong performance of THE PC hardware platform (mainly reflected in the speed and storage capacity), the general configuration software has many strong functions, which are suitable for large monitoring systems.

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

Any HMI product has a system software component. The system software runs in the HMI processor and supports multitasking. The processor needs a small operating system management system software to run.WinCE, Linux, and other general embedded operating systems are commonly used in high-performance tablet computer-based human-computer interface products.

4. Can only connect PLC with the human-machine interface?

That’s not true. Human-machine interface products are to solve the problem of PLC human-computer interaction, but with the development of computer technology and digital circuit technology, much industrial control equipment has a serial port communication ability, so as long as there is a serial port communication ability of the industrial control equipment, such as frequency converter, dc speed regulator, temperature control instrument, for the module can connect human-machine interface products, to realize the human-computer interaction function.

5. Can the HMI be connected to other devices only through the standard serial communication port?

Most of the time. But with the development of computer and digital circuit technology, the interface capability of man-machine interface products is getting stronger and stronger. In addition to the traditional serial (RS232, RS422/RS485) communication interfaces, some human-machine interface products already have data interfaces such as network port, parallel port, and USB port. They can be connected to industrial control devices with interfaces such as network port, parallel port, and USB port to realize human-machine interaction of devices.

6. Can the device with communication function be connected to the human-machine interface product?

It should look something like this. Because the universal human-machine interface products provide a large number of commonly used device communication drivers to choose from; In general, the communication connection between HMI and the device can be completed as long as the communication driver corresponding to the connected device is selected in the picture configuration software of the human-machine interface. 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 communication port type and protocol content of the device to be connected and ask the HMI manufacturer to compile the communication driver of the device on its behalf.

7. Can PC and touch screen communicate directly with PLC to complete HMI function?

B: Sure. However, the corresponding HMI software should be compiled to make the PC a real HMI product.

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

With the development of digital circuits and computer technology, the high, middle, and low functional division of future human-machine interface products will be less and less obvious, and the functions of HMI will be more and more abundant. More than 5.7 inches of HMI products will be all color display, screen life will be longer. Due to the reduction of computation-computer hardware cost, HMI products will take tablet PC computers as the high-end products of HMI hardware, because such high-end products have great advantages in processor speed, storage capacity, types, 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-sized HMI products (with display size less than 5.7 inches) will be widely used in man-machine interaction applications of small mechanical devices due to their advantages in volume and price, as their functions are further enhanced (such as adding IO functions).

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