The increase in adoption of the latest technologies and the introduction of 5G wireless has led to rapid growth and an upsurge in demand for automation across a variety of industries. As of 2019, the global industrial automation sector was valued at $168.81 billion, which is expected to reach $326.14 billion by 2027 while growing at a CAGR (compound annual growth rate) of 8.9%.
In today’s time, programmable logic controllers (PLC) are a key part of the industrial automation sector. Before moving forward, let’s understand what a PLC is.
Do not be intimated when you hear the term programmable logic controllers or PLC. Essentially, a PLC is a specialised computing device that is used in industrial control systems. These devices are versatile that often transcend industries and have a variety of applications such as oil refineries, manufacturing lines, and conveyor systems.
Every PLC has a computer processor that collects different inputs and manipulates them into achieving the desired output. PLCs can be programmed in different methods and hence are valued for their versatility. There are several advantages of PLCs, which include:
- Easily programmable
- Greater shelf life and reliability
- Ease of maintenance
- Greater compatibility and flexibility
Let’s understand the versatility of a PLC with the help of a switch and a light bulb. When the switch is flicked, the bulb can be turned on or off. However, when a PLC is introduced in this experiment, several complex actions can be carried out.
For example, switching off the bulb automatically after it has been on for 30 seconds or making the light bulb blink quickly.
Now, let’s enter the world of PLCs and receive an in-depth understanding about it.
Components of a PLC
- Power Supply and Rack: As the name suggests, the power supply powers up the entire system and makes it run. The rack is a framework that holds all the components in place. This forms the outer layer of the unit that contains the inner workings of the device.
- Central Processing Unit (CPU): CPU is that part of the PLC which encompasses the programming and instructs the rest of the device on what to do and how to act. If the CPU in a PLC does not function correctly, it’s akin to having a body without a brain. The organs and limbs would work in theory, but there is no one to tell them what to do.
- Input/ Output Section (I/O): This part of the PLC is responsible for receiving new information from an outside source and giving out a new function in the guise of an output. The I/O section physically connects the PLC and the equipment that it’s attached to.
How does a PLC Work?
In a nutshell, a PLC receives inputs from external sources, internalises them, and applies its programming to produce the required outputs. It is important to note that the desired results can only be achieved when the correct program is applied.
PLCs are smaller and specialised computers and that is why much of their terminology and language is common with regular computers. The primary difference between them is that regular computers exist in homes and offices, while PLCs function in an industrial world and control inputs and outputs.
Types of PLCs
- Compact PLC: Also known as integrated PLC, a compact PLC includes several modules that are packed into a single case. Hence, the manufacturer decides the inputs and outputs and not the user.
- Modular PLC: A modular PLC consists of different pieces that are plugged into a single rack. These PLCs are available in a variety of different sizes, each offering different levels of power and functionality.
- Small, Medium, and Large PLCs: PLCs are also available in different sizes to make them suitable for different applications.
Applications of PLC
PLC has applications in several industries like thermal power plants, glass industry, paper industry, process automation plants, and cement manufacturing. They also have applications in our everyday lives with regards to road traffic signals, automatic car wash, elevators, and roller coasters.
If you wish to install a PLC for your business, first consult professionals as they will help in ascertaining your overall requirements. Once this is done, they will recommend PLCs to you based on your budget and use.