Which statement best describes interlock safety in PLCs?

Which statement best describes interlock safety in PLCs?

• A. The alarms are silenced
• B. The display refresh rate is reduced
• C. The outputs are prevented from turning on
• D. The maintenance logs are updated

Answer: (C)

Interlock safety in PLCs focuses on stopping any machine action unless all safety conditions are met. This is done by gating the control path so the outputs that power actuators or motors cannot energize when a guard is open, a safety switch is released, or another unsafe condition exists. That makes the statement about the outputs being prevented from turning on the best description of how interlocks operate. In practice, safety interlocks are wired so the safety condition incerates the control circuit; if the condition isn’t satisfied, the circuit opens and the outputs stay off, keeping the equipment in a safe state. Alarms being silenced would hide a warning without stopping motion, the display refresh rate has no safety impact, and maintenance logs are administrative records rather than safety actions.

Interlock safety in PLCs focuses on stopping any machine action unless all safety conditions are met. This is done by gating the control path so the outputs that power actuators or motors cannot energize when a guard is open, a safety switch is released, or another unsafe condition exists. That makes the statement about the outputs being prevented from turning on the best description of how interlocks operate. In practice, safety interlocks are wired so the safety condition incerates the control circuit; if the condition isn’t satisfied, the circuit opens and the outputs stay off, keeping the equipment in a safe state. Alarms being silenced would hide a warning without stopping motion, the display refresh rate has no safety impact, and maintenance logs are administrative records rather than safety actions.