A system and method for providing full-duplex data communications between an electric power distribution station and a power consumer via the power distribution line providing electric power is provided. A switch controlled by a start signal is provided to a gate electrode of a transistor, which is connected to a gate electrode of a bootstrap transistor. One end of the elongate tube is supported on a top end of a central post, and the other end is spirally suspended around the central post. The method may be employed to determine the target polypeptide itself. Said invention enables the slave device to indicate several application groups in response to a single presentation request.