What are Programmable Logic Controllers (PLCs) and What are They Used For?
                     What are Programmable Logic 
Controllers (PLCs) and What are They 
Used For? 
 
Programmable Logic Controllers (PLCs) are a type of computer that is used for automation. They 
are the brains of automated systems and can be programmed to carry out specific tasks. They are 
used in many different industries, such as manufacturing, oil and gas, mining, and construction. 
In these industries, PLCs automate various processes such as turning on lights or opening doors. 
Introduction to PLCs - What are Programmable Logic Controllers? 
Programmable Logic Controllers (PLCs) are used to control industrial processes. They are 
programmed to perform a specific task or sequence of tasks. 
A Mitsubishi PLC is a computer which can be programmed in the same way as a general-
purpose computer, but is designed to control machinery and equipment. 
Programmable Logic Controllers are used in many industries including manufacturing, 
petrochemical, power generation, water pumping and distribution, and food processing. 
The Advantages of PLCs - Why Companies Choose Programmable 
Logic Controllers? 
Programmable Logic Controllers (PLCs) have been around for a long time, but they are still very 
popular in the market and in use. The reason why companies choose PLCs is because they offer 
many advantages that make them more efficient. A PLC can be programmed to monitor and 
control the equipment it's connected to, meaning that it can automate tasks and increase 
efficiency. 
One of the most common reasons for using a PLC is because it improves efficiency. They are 
easy to program, which means that tasks can be automated and monitored by one person. This 
saves time for both employees and employers which leads to an increase in productivity. 
PLC Programming and Advanced Applications in Practical Systems - 
How Complex is Programming a PLC? 
Programming a PLC is not as difficult as you would think. It is just like any other programming 
language and it is made to be user-friendly. The only difference with PLC programming is that it 
uses I/O to control devices. 
The programmable logic controller (PLC) can be programmed in a variety of ways, which depend 
on the type of PLC being used. This article will focus on the most common types: ladder logic 
and sequential function chart (SFC). 
Ladder Logic Programming: Ladder Logic Programming (Ladder) is one of the most popular 
methods for programming a Mitsubishi PLC because it allows for easy troubleshooting and 
debugging. Ladder logic programming uses symbols to represent what needs to happen, such as 
opening or closing a valve, turning on an electric motor or changing the speed of an electric 
motor. It looks like this: A - Start Point   B - Stop Point   C - Point  
If the motor is turning clockwise, then the symbol for "Turn Motor Right" should be used. If it is 
turning counter-clockwise, then symbol for "Turn Motor Left" should be used. 
A programmable logic controller is a device that can be programmed to control industrial 
processes. It has a built-in computer and can be used to automate machinery and other devices. 
A programmable logic controller has three main functions: 
-Control: It provides the ability to control and monitor the input/output of a machine or system, as 
well as its state. 
-Sequencing: It provides the ability to sequence operations on input/outputs, such as opening 
valves or changing speeds of motors. 
-Timing: It provides the ability to set timing intervals for operations with respect to external 
events, such as changes in temperature or pressure. 
PLC Designs 
A Programmable Logic Controller (PLC) is an industrial computer that is used to control both the 
physical and the informational aspects of a process. PLCs are programmed by writing instructions 
in a programming language. 
There are two main programmable logic controller designs: ladder logic and function block 
diagrams. Ladder logic is a programming language that uses symbols to represent different types 
of electrical circuits, such as resistors, capacitors, and switches. Function block diagrams are 
graphical representations of the process that can be programmed with drag-and-drop blocks of 
code.  
A) The block diagram is a graphical representation of the process that can be programmed with 
drag-and-drop blocks of code. 
B) A block diagram is a graphical representation that has been generated in a variety of 
programming languages, including Java or UML. 
C) The step in the workflow of completing an operation such as opening an account, adding 
money to your checking account, or transferring money between accounts, can be represented by 
one or more blocks illustrated  
How to choose the perfect PLC? 
A programmable logic controller is a device that can be programmed to automatically control the 
operations of a system. However, the best PLC is not always the one with the most features. 
There are 5 parameters to consider before making your purchase decision. 
The first parameter is whether you need a Mitsubishi PLC for automation or for control. 
Automation means that you want to use it as an assembly line controller and control means that 
you want to use it for monitoring purposes only. 
The second parameter is whether your system needs analog input or digital input and output. 
Analog input and output can be used in systems that have analog signals, such as sensors, 
whereas digital input and output can be used in systems with digital signals, such as inputs from 
computers or outputs from other controllers. 
The third parameter is: how many outputs are needed in your system? 
The fourth parameter is: what type of signal will be used by your sensors? Finally, the fifth 
parameter is what type of data will be made available to the user. If you want to see air quality 
values for a particular location, use the following command:-a list of different types of sensor 
data.  
Conclusion to the Guide on Programmable Logic 
Controllers - Is There Anything Else You Want to 
Know About PLCs? 
This guide has been an introduction to PLCs. We have seen what a PLC is, how it works and 
what it can be used for. We also looked at the different types of PLCs and their uses. 
In this section, we will conclude this guide with a few final questions that you may want to know 
about PLCs. 
Is there anything else you want to know about PLCs? Contact Mitsubishi Electric India, to 
check out the best range of PLCs available.