| 摘要 |
PURPOSE:To save power consumption by turning off a power source of an unnecessary circuit, when a frame synchronization is secured and when a part of a synchronizing word and one-unit length data by which a bit error in data is not detected are received, in a slave station. CONSTITUTION:In a master station, a data output of a frame constitution as shown in a figure (a) is generated. A, B and S denote one frame, one unit length, and a synchronizing word, respectively, and D1-Dn are one-unit length data, and (n) pieces have all the same contents. In a receiving system of a slave station C, the synchronizing word is detected by a detecting circuit 26, it is checked that the synchronizing word is detected correctly by a frame synchronizing circuit 27, and the synchronization is secured. After the synchronization is secured, a power source except that of a circuit required for maintaining the frame synchronization becomes off. In the figure (a), however, in the part of the synchronizing word S and the part of the data D1, the power source is set to on by a power source on and off controlling circuit 30. When a bit error is detected in the data D1, the power source is held in on-state, whether an error exists or not is checked by a bit error detecting circuit 28 with regard to the data D2, and the same processing as that of the data D1 is executed. |
