Free
8 min

Lesson 6 — SET/RST Latching

curriculumlessonset-rstlatch
Lesson 6 — SET/RST Latching scenario preview

Ready to build this?

Sign up free — no credit card required. This scenario is included in the free tier.

Sign up to play this scenario →

Already have an account? Log in

Briefing

SET (S=) and RESET (R=) coils are the explicit latch instructions. S= turns a bit on and it stays on even if the rung goes false. R= turns it off and it stays off. Two rungs, clean and readable — no feedback branch needed.

Objectives

  • START pulse sets MOTOR (stays on)
  • STOP pulse resets MOTOR (stays off)

Hints

  • Rung 1: | START | S= MOTOR ; — this latches MOTOR on.
  • Rung 2: | STOP | R= MOTOR ; — this resets MOTOR.

I/O Table

Inputs

START

Momentary start push-button (NO)

BOOL · %I0.0

STOP

Momentary stop push-button (NO)

BOOL · %I0.1

Outputs

MOTOR

Motor contactor coil

BOOL · %Q0.0

Your program will be tested against:

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

  1. #1START pulse sets MOTOR

    Brief START → MOTOR on and stays on

  2. #2STOP pulse resets MOTOR

    While running, brief STOP → MOTOR off

Ready to build this?

Sign up free — no credit card required. This scenario is included in the free tier.

Sign up to play this scenario →

Already have an account? Log in