Beginner 06 — Latch the start (SET coil)
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Briefing
Now we fix stage 4. A SET coil (S=) latches a bit on. Pulse START once — the LIGHT turns on and stays on, even after you release the button. That's how real machines work: you tap the start button, the motor runs. You don't stand there holding the button down all day.
Objectives
- A brief START pulse turns LIGHT on
- LIGHT stays on after START is released
Hints
- Use a SET coil instead of a normal coil. In IEC: | START | S= LIGHT ;
- Once a SET coil fires, the bit stays on until something resets it. We add the reset in the next scenario.
I/O Table
Inputs
STARTMomentary start push-button (NO)
BOOL · %I0.0
Outputs
LIGHTIndicator lamp
BOOL · %Q0.0
Your program will be tested against:
All test cases run automatically when you submit. Assertions are hidden until you pass.
- #1Pulse START → LIGHT latches on
A momentary START sets LIGHT and it stays on after release
- #2Idle → LIGHT off
Without ever pressing START, LIGHT stays off
Related scenarios
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