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The full narration of this lesson in HINGLISH — read along, or revisit any part.
Hey Prem, imagine you're in a factory and a machine suddenly starts moving — but who told it to move? [short pause] The answer is hiding inside a small box called a PLC.
A PLC is basically a tiny computer that controls machines. But it can't see or touch anything — it needs eyes and hands.
Those eyes and hands are called Input and Output cards — or I/O cards. Let's look at the real thing.
Input cards are the eyes. They bring signals from sensors into the PLC — like a button being pressed, or a temperature reading.
Output cards are the hands. They take the PLC's decision and send a signal to make something happen — like starting a motor or turning on a light.
Here's the flow: a sensor sends a signal to the Input card — the PLC's brain decides what to do — then the Output card makes it happen.
Think of it like this: Input cards are like your eyes seeing a red light, your brain decides to stop, and Output cards are your foot pressing the brake.
And here's the interesting part — a single PLC can have dozens of Input and Output cards, each handling many signals at once.
So next time you see a machine working automatically, remember — it's just Input cards seeing, a brain deciding, and Output cards doing.
And that's the whole idea, Prem. Input cards bring the world in — Output cards send action back out. Simple, powerful, and everywhere.