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latching coil

1 article tagged “latching coil”.

Flat vector ladder logic diagram showing OTL latch coil and OTU unlatch coil rungs with a shared retentive bit and memory icon
ladder logiclatching coilplc programming

OTL and OTU Latch Coils in Ladder Logic Explained

OTL and OTU latch coils hold state through a power cycle. Learn how they work in ladder logic, how they differ from seal-in rungs, and when each belongs in your program.

Jul 30, 2026 · 8 min read

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