PLC is more studious than MCU. PLC is generally realized on the basis of understanding the technological process and software programming and debugging. Microcontrollers generally need to have a deep understanding of hardware and software programming. So PLC is easy to use, but single chip microcomputer is difficult to master. In the past few years, the salary of PLC is easier to increase than that of single chip microcomputer. But to reach the advanced stage of pure technology, the two are the same.
When the programmable logic controller is put into operation, its working process is generally divided into three stages, namely, input sampling, user program execution and output refresh.
The completion of the above three stages is called a scanning cycle. In the whole operation process, the CPU of the programmable logic controller repeatedly executes the above three stages at a certain scanning speed.
Brief introduction of single chip microcomputer:
Microcontroller is an integrated circuit chip. It is a small and perfect microcomputer system integrating CPU, RAM, ROM, various I/O ports, interrupt system, timer/counter (possibly including display drive circuit, pulse width modulation circuit, analog multiplexer, A/D converter, etc.). ) integrated into silicon chip by VLSI technology.
Widely used in the field of industrial control. From the 1980s, from the then 4-bit and 8-bit single-chip microcomputer to the present 300M-meter high-speed single-chip microcomputer.