When the machine is in manual mode, which mode should be locked out to prevent unintended automatic operation?

• A. Manual Mode
• B. Emergency Stop
• C. Remote Operation
• D. Automatic Mode

Answer: (D)

When you’re operating in manual control, you want to prevent the system from switching into a pre-programmed automatic sequence. Locking out Automatic Mode stops any automatic operations from starting, ensuring the machine stays under direct human control and reduces the risk of unexpected cycles or motion.

Manual Mode should remain available for direct control, being the state you’re in by choice. The Emergency Stop is for an immediate, safety-critical shutdown and isn’t about preventing mode transitions. Remote Operation could introduce control from another source, but if Automatic Mode is locked out, the system cannot enter automatic behavior regardless of remote commands. Locking Automatic Mode directly addresses the risk of unintended automatic operation.