Do You Really Know The Human Computer Interface (HMI)?
Q1: Is HMI only used for LC connection?
This is not true. HMI products were originally produced to solve the problem of PLC human-computer interaction. However, with the development of computer technology and digital circuit technology, many industrial control devices have the capability of serial communication interface. Therefore, as long as the industrial control unit has the capability of serial communication interface, such as VFD(variable frequency drive), DC voltage regulator, temperature control instrument and data acquisition module, it can connect HMI products to achieve human-computer interaction.
Q2: What is the difference between HMI and “HMI”? Touch screen “;?
Strictly speaking, there are essential differences between them. Because “touch screen” only involves the available hardware of HMI products, which are input devices installed in front of the display screen to replace some functions of the mouse and keyboard. HMI products are human-computer interaction devices including hardware and software. In the industry, people call HMI products with touch input functions as” Touch screen “is unscientific. Touch screen”;
Q3: Does the HMI product have an operating system?
HMI products have system software components. The system software runs on the HMI processor and supports multi task processing. Running the processor requires small management system software. High performance HMI products based on tablet computers usually use general embedded operating systems, such as WinCE and Linux.
Q4: What is the difference between HMI and SCADA?
HMI products are often referred to as “HMI products”. Touch screen Including HMI hardware and corresponding special SCADA software. Generally, the HMI hardware of each manufacturer uses different SCADA software, and the main equipment type connected is PLC.
SCADA software is a general tool software running on PC hardware platform and Windows operating system, which can be used to configure HMI products together with PC or industrial computer.
The general SCADA software supports many types of equipment, including PLC, PC board, meter, VFD and module. In addition, SCADA software has many powerful functions suitable for large-scale monitoring system with the powerful performance of PC hardware platform(mainly in speed and storage capacity).
Q5: Is the device with communication function connected to HMI product?
This is usually true. Common HMI products provide common device communication drivers for selection. Generally, in the SCADA software of HMI products, if the communication driver corresponding to the connected device is selected, the communication connection between HMI and the device will be completed.
If the SCADA software of the HMI product does not connect the communication driver of the device, the user can notify the communication port type and protocol content of the device to be connected to the HMI product manufacturer, and require the manufacturer to create a communication driver for the device.
Q6: Is the HMI connected to the device only through the standard serial communication interface?
In most cases, with the development of computer technology and digital circuit technology, the interface capability of HMI products is becoming stronger and stronger. In addition to the traditional serial(RS232, RS422/RS485) communication interfaces, some HMI products also have network interfaces, parallel interfaces, USB interfaces and other data interfaces, which can connect industrial control equipment with the same interface to achieve human-computer interaction of the equipment.
Q7: Can the PC with touch screen directly communicate with PLC to realize HMI function?
Of course, it is important to compile the corresponding HMI software to make PC a real HMI product.
Q8: What is the trend of HMI?
With the development of digital circuit technology and computer technology, the functional level of HMI products will be less and less in the future, and the functions of HMI will be more and more abundant. HMI products with a screen size of more than 5.7 inches will be displayed in full color, and the use time will be longer.
Tablets will be regarded as high-end products of HMI hardware to reduce the cost of computer hardware. This is because these products have great advantages in processor speed, storage capacity, type and number of communication interfaces, network capacity and software resource sharing, which is the future development direction of HMI products.
Of course, the function(such as adding IO function), size and price of small HMI products with display size less than 5.7 inches will be further strengthened and widely used in HMI applications of small mechanical equipment.