Reset (unlatch) coil symbol
Also called Unlatch coil, OTU, Reset coil, R coil
Resets its bit to 0 when the rung is true. In Allen-Bradley PLCs it is OTU, output unlatch, marked U.
IEC 61131-3What the reset (unlatch) coil symbol means
Resets its bit to 0 when the rung is true. In Allen-Bradley PLCs it is OTU, output unlatch, marked U.
How it is drawn
Where you see it
Clearing a latched bit: a fault reset, a sequence reset or an alarm acknowledge.
Related symbols
Frequently asked questions
What does the reset (unlatch) coil symbol look like?
A coil marked R (U on Allen-Bradley).
Where is a reset (unlatch) coil used?
Clearing a latched bit: a fault reset, a sequence reset or an alarm acknowledge.
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