Dear friends, I am Electrician Old Li. In our modern factories, the PLC is indeed the “nerve center” with a very important status. But do you know? It seems complex and mysterious, but the workflow actually consists of three steps: input sampling, program execution, and output refreshing. However, within these three steps lies a lot of knowledge, creating a gap between novice and experienced engineers, causing many engineers to struggle upon contact. Today, Old Li will have a good chat with everyone.