Set (latch) coil symbol
Also called Latch coil, OTL, Set coil, S coil
Sets its bit to 1 when the rung is true and leaves it at 1 when the rung goes false. In Allen-Bradley PLCs it is OTL, output latch, marked L.
IEC 61131-3What the set (latch) coil symbol means
Sets its bit to 1 when the rung is true and leaves it at 1 when the rung goes false. In Allen-Bradley PLCs it is OTL, output latch, marked L.
How it is drawn
Where you see it
Remembering an event until it is acknowledged: a fault, a completed step, a latched alarm.
Related symbols
Frequently asked questions
What does the set (latch) coil symbol look like?
A coil marked S (L on Allen-Bradley).
Where is a set (latch) coil used?
Remembering an event until it is acknowledged: a fault, a completed step, a latched alarm.
Every interlock in your PLC logic, tested and signed.Deskely holds the cause and effect and function test records for every system, checked as they are signed, so the logic is proved before start-up.
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