Which element should be present on a barrier device to verify door closure status?

Which element should be present on a barrier device to verify door closure status?

• A. Sensors
• B. Cameras
• C. Keypad
• D. Voice annunciator

Answer: (A)

Verifying door closure status relies on sensing the door’s position. A door position sensor is installed on the barrier to detect whether the door is fully closed (and typically latched) and to report that state to the access control panel. This real-time feedback is essential so the system can make correct decisions—relocking after passage, permitting egress when appropriate, and maintaining security logs. Other options don’t provide this direct, automatic state reporting: cameras may show the door but don’t reliably confirm its closed state to the controller; a keypad handles input for access but not the door’s physical position; a voice annunciator communicates status to people but doesn’t feed the closure state into the control logic. So the sensor that detects door position is the element that should be present.

Verifying door closure status relies on sensing the door’s position. A door position sensor is installed on the barrier to detect whether the door is fully closed (and typically latched) and to report that state to the access control panel. This real-time feedback is essential so the system can make correct decisions—relocking after passage, permitting egress when appropriate, and maintaining security logs. Other options don’t provide this direct, automatic state reporting: cameras may show the door but don’t reliably confirm its closed state to the controller; a keypad handles input for access but not the door’s physical position; a voice annunciator communicates status to people but doesn’t feed the closure state into the control logic. So the sensor that detects door position is the element that should be present.