What are the differences between HMI and PLC
Editor to share with you what are the differences between HMI and PLC, I believe that most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!
Difference: HMI (man-machine interface) is a kind of intelligent operation control and display device; when touching the screen, the resistance and voltage on the resistance network can change and the touch position can be calculated by the software. PLC is a kind of digital operation controller with microprocessor for automatic control, which can load control instructions into memory at any time for storage and execution.
HMI
Man-machine interface (Human MachineInterface), referred to as HMI, also known as touch screen monitor, is a kind of intelligent operation control and display device. When touching the screen, the resistance and voltage on the resistance network can change and the touch position can be calculated by the software.
Man-machine interface (HMI), also known as "man-machine interface", its main function is to help people establish contact with computers and exchange information between input / output devices, including keyboards, monitors, printers, mice and so on.
PLC
Programmable logic controller (ProgrammableLogic Controller,PLC), a digital operation controller with microprocessor for automatic control, can load control instructions into memory at any time for storage and execution.
PLC consists of CPU, instruction and data memory, input / output interface, power supply, digital-analog conversion and other functional units.
There are many ways of communication between HMI and PLC, the most common of which are Ethernet and serial port.
What is the relationship between HMI and PLC?
They are actually "bitter enemies". HMI is a "little man" and PLC is a "good old man".
Because PLC painstakingly calculates the information collected on the spot [captured by field sensors and converted into signals that can be recognized by PLC, such as 4~20mA current signal].
However, HMI uses data lines [Ethernet or serial data lines] to send all these data away from the communication port of PLC. In addition, HMI also instructs PLC to do this and that.
In addition, the glamorous side is dominated by HMI [process control and display], and PLC has to stay miserably in the dark box [control cabinet].
These are all the contents of this article entitled "what are the differences between HMI and PLC". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!
