IntermediateState Coil / Fault Coil~15 min

State Coil / Fault Coil

A fault lamp that latches ON when any alarm condition occurs, even briefly, and only clears on Reset. And if the condition is still present when Reset is released, the fault comes right back.

New here? How to use it

Your goal

  • OverTemp OR OverPress turns the Fault lamp ON.
  • Fault stays ON after the condition goes away (latched).
  • Pressing Reset clears the fault.
  • If the condition is still active when Reset is released, Fault turns back ON.
Stuck? Show hints (3)
  1. One rung, three parallel paths: NO OverTemp, NO OverPress, and NO Fault (the seal), all OR'd in the first column.
  2. Use the third branch row for the seal contact, with vertical links joining all rows after column 1.
  3. A NC contact of Reset in series after the parallel group is what clears the latch.

Pattern from Contact & Coil's classic ladder logic series.

I/O for this exercise4 tags Ā· show
Inputs
OverTempOver-temperature switch
OverPressOver-pressure switch
ResetFault reset push button
Outputs
FaultFault lamp
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