What is a PLC and what does a PLC do?


Here are some quick answers to some common questions that we see on PLCs.

What is the definition of a PLC?

PLC stands for Programmable Logic Controller. Some people also refer to them as industrial computers.

What does a PLC do?

A PLC on a simple level uses logic to convert an input into a set output. This is much like a computer turns you pushing a button on your keyboard (input) into a letter being displayed on a screen (output). A PLC will generally do the same thing in an industrial application. This can be something simple like pushing a green button will make your conveyor run to complex series of movements by a robot that are monitored through sensors.

How do I pick a PLC?

There are a vast variety of PLCs available and range in complexity and price. The first thing that you will need to do is define what you want your PLC to control (outputs) and how you want to control it(inputs) With this information you will know the number of inputs and outputs that you will need.

Other important factors in picking a PLC are Supply Power, Operator Interface, Communication Protocols, and Programming. Here we have another post that can help you in choosing a PLC.


Programmable Rationale Controllers (PLC) are regularly characterized as smaller than expected mechanical PCs that contain equipment and programming used to perform control capacities. All the more explicitly, a PLC would be utilized for the mechanization of modern electromechanical procedures, for example, control of hardware on plant mechanical production systems, entertainment rides, or nourishment handling. They are intended for various game plans of computerized and simple sources of info and yields with expanded temperature ranges, invulnerability to electrical clamor, and protection from vibration and effect. A PLC will comprise of two essential segments: the focal handling unit (CPU) and the Info/Yield (I/O) interface framework.

PLC sources of info and yields

The CPU controls all framework action fundamentally through its processor and memory framework. The CPU comprises of a microchip, memory chip and other incorporated circuits to control rationale, observing and interchanges. The CPU has diverse working modes. In programming mode the CPU will acknowledge changes to the downloaded rationale from a PC. At the point when the CPU is set in run mode it will execute the program and work the procedure. Info information from associated field gadgets (e.g., switches, sensors, and so forth.) is prepared, and afterward the CPU "executes" or plays out the control program that has been put away in its memory framework. Since a PLC is a devoted controller it will process this one program again and again. The time it takes for one spin through the program is called filter time and happens rapidly (in the scope of 1/1000th of a second, contingent upon your program). The memory in the CPU stores the program while likewise holding the status of the I/O and giving a way to store esteems.