What is a PLC?

Understanding industrial process control with PLCs.
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Ever wondered how industries keep their processes running smoothly behind the scenes? Enter the Programmable Logic Controller, or PLC. In simple terms, it's like the brain of industrial automation, quietly managing tasks in sectors like oil, steel, and automotive.

Picture a scenario where a button press sets a motor in motion – that's the PLC at work. Let's dive into how this unsung hero simplifies complex operations and keeps everything ticking seamlessly.

What is a PLC?

A Programmable Logic Controller or PLC is simply a special computer that is programmed to control certain processes in industries like petroleum, Steel, or automotive.

Every PLC is composed of three main parts: Input, CPU, and Output. Suppose that we have an electrical motor and a push button.

We want the motor to turn on when the button is pressed. When the button is pressed again, we want the motor to turn off. This function is similar to the function of the power button on your TV remote.

To do this, we must first write a program for this operation on a computer and then download it to the CPU.

Then we connect the switch to the input and the motor to the output. Now if we press the button, an electrical signal will be sent to the PLC.

The PLC input will deliver this signal to the CPU but first must present it in a format that the CPU can process.

Why? Because the CPU is a computer

system and cannot process the raw electrical signal. The CPU will process the data received and send the result to the output.

The output turns the data to a raw electrical signal again, applies that to the motor, and turns it on.

Now if we press the button again, the process repeats and the motor will turn off.

Programmable Logic Controller

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