1, HMI can only be connected to PLC?
Not so. HMI products are designed to solve the problem of PLC human-machine interaction and produced, but with the development of computer technology and digital circuit technology, many industrial control devices have the ability to communicate with the serial port, so as long as there is a serial communication capability 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.
2,Human-machine interface and people often say "touch screen" what is the difference?
Strictly speaking, the two are fundamentally different. Because the "touch screen" is only the hardware part that may be used in the human-machine interface products, it is an alternative to the mouse and keyboard part of the function, installed in the front of the display of the input device; while the human-machine interface products are a kind of human-computer interaction equipment that 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.
3,Human-machine interface products, whether there is an operating system?
Any human-machine interface products have a system software part, the system software runs in the HMI processor, support for multi-tasking functions, 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.
4,Human-machine interface and configuration software, what is the difference?
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. The configuration software is running on the PC hardware platform, windows operating system under a general 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 performance is strong (mainly reacting to the speed and storage capacity), the general configuration software is also very strong function, applicable to the Large-scale monitoring system.
5,Is there a communication function of the device must be able to connect with the human-machine interface products?
It should be so. Because common HMI products provide a large number of commonly used device communication drivers for selection; in general, as long as the HMI screen configuration software to select the corresponding communication driver with the connected device, you can complete the communication connection between the HMI and the device. If the configuration software of the selected HMI product does not have the communication driver for the connected device, the user can inform the manufacturer of the HMI product of the type of the communication port and the content of the protocol of the connected device, and ask the HMI manufacturer to prepare the communication driver for the device on behalf of the manufacturer.
6, PC plus touch screen, can directly communicate with the PLC to complete the HMI function?
Of course. However, we also need to prepare the corresponding HMI software in order to make the PC become a real HMI product.
7, the human-machine interface can only be connected to other devices through the standard serial communication port?
In most cases this is the case. However, 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, some HMI 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 the industrial control equipment to achieve 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 future of the human-machine interface 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 products 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 functions (such as increasing the IO function), it will be widely used in small machinery and equipment for human-computer interaction applications.