What is the function of a key fob in electronic access control?

The function of a key fob in electronic access control primarily revolves around granting access to authorized users via electronic means. Key fobs are small devices that emit a radio frequency signal when activated, which is received by the access control system. This system is designed to allow entry only to those users who have been authenticated.

When an authorized user approaches a door equipped with an electronic lock, they can present their key fob to the reader, which verifies the credentials stored in the fob. If the credentials match those in the control system's database, access is granted. This method enhances both security and convenience compared to traditional mechanical keys, as key fobs can be easily reprogrammed or deactivated if lost or stolen, ensuring that access control can be promptly maintained without the need for physical key changes.

In contrast, other options do not accurately describe the primary function of a key fob. While a fob can be a part of a larger security system, it does not physically serve as a backup key, trigger alarms directly, or monitor user activity on its own. Its main purpose is firmly rooted in providing secure, electronic access to authorized users.