Source : Free On-Line Dictionary of Computing

automatic baud rate detection
     
         (ABR, autobaud) A process by which a
        receiving device determines the speed, {code level}, and {stop
        bits} of incoming data by examining the first character,
        usually a preselected sign-on character.  ABR allows the
        receiving device to accept data from a variety of transmitting
        devices operating at different speeds without needing to
        establish data rates in advance.
     
        (1996-06-18)