Many beginners often confuse PLCs and microcontrollers. Today, let’s discuss what the differences are:
PLC is short for Programmable Logic Controller. It is a digital electronic device with a microprocessor, equivalent to a small computer, used as a digital logic controller for automation, which allows control instructions to be loaded into memory for storage and execution at any time.
It is modularly composed of CPU, instruction and data memory, input/output units, power modules, digital/analog units, etc.It has strong versatility, ease of use, wide adaptability, high reliability, strong anti-interference capability, and simple programming.
A microcontroller, also known as a microcontroller unit (MCU), is not a chip that performs a specific logical function, but integrates a computer system onto a single chip. It is equivalent to a miniature computer, and compared to a computer, a microcontroller only lacks I/O devices, and is widely used in industrial control.
PLC is a product built on top of a microcontroller;
Microcontroller is a programmable integrated chip.
PLC is synthesized from a microcontroller and peripheral circuits, and manufacturers only need to provide programming software to program using ladder diagrams;
Microcontroller is developed from the ground up, with programming done using assembly or C language, where timing programs must be calculated from the crystal oscillator.
PLC is relatively expensive, ranging from hundreds to thousands, but has a short development cycle, is efficient, stable, and has higher performance;
Microcontroller has low development costs, ranging from a few to several tens, but has a longer and slower development cycle.
PLC‘s programming languages include: Ladder Diagram (LD), Instruction List (L), Function Block Diagram (FBD), Sequential Function Chart (SFC), Structured Text (ST).
Microcontroller programming languages: C language or assembly language, also uses built-in programming languages (such as ASM for 8051 microcontrollers).
PLC has a certain degree of interchangeability, is stable, high quality, and has standard programming software.
Microcontroller functions vary widely, application systems are uneven, making usage and maintenance more difficult.
For single projects or those with few repetitions, selecting PLC is more convenient, with a higher success rate and better reliability, but at a higher cost.
For large-scale supporting projects, using microcontroller systems is more cost-effective and efficient, but requires an excellent R&D team to ensure system stability.
In essence:
PLC is a mature microcontroller system with strong versatility. At the same time, PLC widely uses ladder diagrams, which gives it certain advantages in programming.
On the other hand, microcontrollers can form various application systems, but it is still an integrated circuit and must be combined with other components and software to be applicable.
Therefore, in life, we must choose based on specific situations! Have you learned it yet?
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