What safety feature prevents robot motion when a guard gate is open?

• A. Safety interlocks
• B. Visual warnings
• C. Training programs
• D. Maintenance scheduling

Answer: (A)

Preventing robot motion when a guard gate is open relies on safety interlocks. A safety interlock is a safety-rated switch placed on the guard that detects whether the door or gate is closed and secured. It is wired into the robot’s safety circuit so that the moment the gate opens, the interlock changes state and the safety circuit trips, stopping the robot or preventing it from starting. This design provides an automatic, fail-safe way to keep the robot from moving into a hazardous area while access is open. In many systems, interlocks are built with redundancy or two-channel logic to reduce the chance that a fault could bypass protection, and they may require the operator to re-close and reset after opening the gate.

Visual warnings, training, and maintenance play important safety roles, but they do not automatically stop the robot if the gate is opened. The interlock is the mechanism that directly enforces the safe state by preventing motion until the guard is securely closed.