Abstract: A communication system includes a network formed by a plurality of control units, each operated in a high power consumption mode and a low power consumption mode. A selected one or more of the control units act solely or in cooperation with each other to implement a specific function. Each of the selected one or more of the control units related to the specific function is set in the high power consumption mode. Each of the non-selected control units unrelated to the specific function is set in the low power consumption mode.

Abstract: An object of the present invention is to obtain an acceleration sensor that can reliably detect acceleration when inclination of an inclining member is within a fixed range, and that can reduce unnecessary movement of relevant members when inclination of the inclining member is outside of the range, so that space efficiency in an inner portion is high. In the present invention, a gear of a fixed gear fixed at a seat cushion is formed in only a portion in the circumferential direction, and a portion at which the gear is not formed is a sliding surface. One of teeth among a plurality of teeth of a pinion of a revolving gear is short, to form a notched tooth portion. In a state in which the forward-collapsed angle of a seatback exceeds a predetermined angle, the notched tooth portion faces the sliding surface and the revolving gear body no longer rotates. At this time, since a bracket at which a sensor ball is mounted also does not rotate, the bracket is held at a fixed position relative to a frame plate.