In LD programming, an output that stays energized until a second coil is made TRUE is called a(n) _____.

In LD programming, an output that stays energized until a second coil is made TRUE is called a(n) _____.

• A. Latch relay
• B. Timed coil
• C. Pulse relay
• D. Memory coil

Answer: (A)

In ladder logic, a latch (self-holding) output is one that, once energized by its set input, remains on even after that input goes FALSE, until a separate reset action turns it off. This behavior is exactly what’s described by “an output that stays energized until a second coil is made TRUE”—the first coil energizes and the output latches, and a second coil (the reset) breaks the hold when it goes TRUE. The other options describe different behaviors: a timed coil turns off after a delay, a pulse relay produces a brief pulse, and a memory coil isn’t the standard term for this self-holding behavior. So the latch relay best captures the described function.

In ladder logic, a latch (self-holding) output is one that, once energized by its set input, remains on even after that input goes FALSE, until a separate reset action turns it off. This behavior is exactly what’s described by “an output that stays energized until a second coil is made TRUE”—the first coil energizes and the output latches, and a second coil (the reset) breaks the hold when it goes TRUE. The other options describe different behaviors: a timed coil turns off after a delay, a pulse relay produces a brief pulse, and a memory coil isn’t the standard term for this self-holding behavior. So the latch relay best captures the described function.