Which statement describes a non-retentive timer’s typical usage for starting motors in sequence?

Which statement describes a non-retentive timer’s typical usage for starting motors in sequence?

• A. TON On Delay timer starting motors in sequence
• B. TOF Off Delay timer starting motors in sequence
• C. RTO Retentive timer starting motors in sequence
• D. Time-Driven Sequencing starting motors in sequence

Answer: (A)

An On-Delay timer (TON) provides a defined pause after a trigger turns on, before its output activates. Because it’s non-retentive, the elapsed time resets as soon as the trigger goes false, so each startup sequence begins with a clean slate. This makes it ideal for starting motors in sequence: energize the first motor, let the TON count up, and when the preset delay is reached, energize the next motor, and so on. Off-Delay timers would keep a motor on for a while after the trigger is removed, which isn’t what you want for sequential starts. Retentive timers remember elapsed time across interruptions, which can cause timing to carry over incorrectly between cycles. The idea of “time-driven sequencing” describes a method, not a specific timer type. So the best match for starting motors in sequence with a resettable, predictable delay is using an On-Delay timer.

An On-Delay timer (TON) provides a defined pause after a trigger turns on, before its output activates. Because it’s non-retentive, the elapsed time resets as soon as the trigger goes false, so each startup sequence begins with a clean slate. This makes it ideal for starting motors in sequence: energize the first motor, let the TON count up, and when the preset delay is reached, energize the next motor, and so on. Off-Delay timers would keep a motor on for a while after the trigger is removed, which isn’t what you want for sequential starts. Retentive timers remember elapsed time across interruptions, which can cause timing to carry over incorrectly between cycles. The idea of “time-driven sequencing” describes a method, not a specific timer type. So the best match for starting motors in sequence with a resettable, predictable delay is using an On-Delay timer.