door 14 to close if it is already open the garage door operator 12 can be any of a number of known configurations such as a belt drive chain drive or other mechanism which cooperates with the garage door 14 to automate opening and closing of garage door 14 the authentication system 22 depending upon the level of security used by the entry control system 10 will decode or otherwise receive the transmitted radio frequency signal and translates it into a signal which may be compared to signals from authorized users 28 that is the transmitted radio frequency signal will contain a coded designation which will be checked for correspondence with one or more entries in a list of coded designations or authorized users 28 by the authentication system 22 if the transmitted signal corresponds to a designation within authorized users 28 the appropriate signal is sent to the controller 18 which will then cause control signal 20 to activate the garage door operator 12 causing garage door 14 to open or close operation of the keypad 32 is functionally similar to rf transmitter 30 the keypad 32 shown in fig1 is intended to represent a keypad which may be found at an unsecured location such as an outside wall 33 of the garage 16 the keypad 32 is connected to the authentication system 22 in such a way.