US Patent 9196104 Wireless access control system and related methods

A wireless access control system includes a remote access device. A plugin device communicates with the remote access device. A lock controls the ability to lock and unlock a door in which the lock is disposed. The lock is in communication with the plug in device. The plug in device determines a distance between the remote access device and the lock and causes the lock to communicate with the remote access device when the remote access device is at a distance less than or equal to a predetermined distance from the lock to enable the lock to be unlocked.