US Patent 7057494 Method and apparatus for a rolling code learning transmitter

A barrier movement operator system having a receiver for receiving, learning and responding to transmitted rolling code access codes. The barrier movement operator provides a method and apparatus for learning valid security codes by a security code receiver comprising receiving a first previously learned security code and beginning a learn mode operation in response thereto, within a predetermined period of time, receiving a second security code, having a predetermined relationship to the first security code; and storing a representation of the second security code as a valid security code.