PLC Stack Light Logic

Most beginners overcomplicate stack lights in PLC programs. They’ll fight with timers, mix up which color means what, and end up with a panel where nobody on the floor is quite sure if a machine is actually running or not. For a light that’s supposed to make things clear… that’s a problem. In my latest YouTube video I walk through a simple example: Machine 1 runs for 10 seconds (red light ON while running) Machine 2 runs for 20 seconds (red light ON while running) Green only comes on when the machine is fully stopped No fancy tricks. Just basic timers and outputs in ladder logic that a new technician can read without guessing. Personally, I care a lot more about “can the night shift understand this at 3am?” than “is this the most clever rung I could write?”. If you’re new to PLCs, or you’re teaching apprentices, this kind of clear status indication matters way more than showing off with complex logic. I also show how to structure the code so you don’t confuse machine status with fault conditions later. If you work with PLCs, I’d love to know: what platform are you mostly using on the plant floor these days? #plc #industrialautomation #ladderlogic