Interlocks are defined as

Interlocks are defined as

• A. A device that triggers alarms
• B. Any arrangement of devices where the operation of one control or mechanism brings about or prevents initiation of operations of another
• C. A type of motion controller
• D. A safety gate

Answer: (B)

Interlocks are all about gating what can and cannot happen in a system. They ensure that the start or continuation of an operation depends on other conditions being met, so a machine won’t begin or will be prevented from running if a safeguard is not in the right state. That means the defining idea is the arrangement of devices where one control or mechanism either enables or blocks the initiation of another operation. That’s why the best answer describes interlocks as “any arrangement of devices where the operation of one control or mechanism brings about or prevents initiation of operations of another.” It captures the mutual dependence that keeps a process safe: you only get a start or a run when all required conditions are satisfied. The other concepts don’t fit this definition as precisely. An alarm trigger is about signaling, not preventing initiation. A motion controller handles the sequencing of movement, not the protective gating between controls. A safety gate is a protective barrier, which may incorporate an interlock, but the interlock itself is the gating arrangement, not the barrier alone.

Interlocks are all about gating what can and cannot happen in a system. They ensure that the start or continuation of an operation depends on other conditions being met, so a machine won’t begin or will be prevented from running if a safeguard is not in the right state. That means the defining idea is the arrangement of devices where one control or mechanism either enables or blocks the initiation of another operation.

That’s why the best answer describes interlocks as “any arrangement of devices where the operation of one control or mechanism brings about or prevents initiation of operations of another.” It captures the mutual dependence that keeps a process safe: you only get a start or a run when all required conditions are satisfied.

The other concepts don’t fit this definition as precisely. An alarm trigger is about signaling, not preventing initiation. A motion controller handles the sequencing of movement, not the protective gating between controls. A safety gate is a protective barrier, which may incorporate an interlock, but the interlock itself is the gating arrangement, not the barrier alone.