Which of the following lists are common protective measures found in robotic cells?

• A. Emergency stop devices only
• B. Fencing or safeguarding barriers, safety interlocks, and emergency stop devices.
• C. Fencing or safeguarding barriers only
• D. Safety interlocks and alarm systems

Answer: (B)

Protective measures in robotic cells rely on three complementary elements: physical barriers to separate people from the robot, safety interlocks on access points to automatically stop when a barrier is opened, and emergency stop devices to halt all motion immediately in an urgent situation. The barrier creates a clear boundary so a person can’t reach into the robot’s work envelope during operation. Safety interlocks ensure that opening a gate or door stops the robot and prevents it from restarting until the barrier is reset, providing automatic protection if someone enters the boundary. Emergency stop devices give a rapid manual shutdown of all motion, even if other safety functions are not actively engaged. Together, these three form a robust, layered safety approach: preventing entry, stopping on access, and providing a quick override in an emergency. Without all three, gaps remain—barriers alone don’t stop motion if something goes wrong inside the zone, interlocks without a barrier can’t prevent entry, and emergency stops without barriers or interlocks can’t ensure immediate automatic safe shutdown when access occurs.