Beginner 04 — Stop button (NC contact)

Briefing

The light is on by default. Pressing STOP_BUTTON should turn it OFF. That's a normally-closed (NC) contact — current passes through it until the input is true, then it breaks. This is exactly how a real stop button works: idle = circuit complete, pressed = circuit broken. Same idea as an e-stop.

Objectives

• When STOP_BUTTON is false (released), LIGHT is on
• When STOP_BUTTON is true (pressed), LIGHT is off

I/O Table

Your program will be tested against:

All test cases run automatically when you submit. Assertions are hidden until you pass.

1. #1STOP released → LIGHT on

   NC contact lets current through when input is false

2. #2STOP pressed → LIGHT off

   NC contact breaks the rung when input goes true