| 摘要 |
PURPOSE:To eliminate necessity of individual time correction at the terminal by forming the system so that the controller can set the time for a clock incorporated, to the terminal and correcting the clock to the standard time controlled by a master station by using the communication function in a data channel. CONSTITUTION:In addition to the data polling in routine service at a master station, side the central computer 2 periodically receives the time data by means of a standard clock 12, and supplies simultaneously the time information to all the terminals via a data transmitter 3 by common address. After receiving this data signal, the terminal decodes it by a data receiver 7, and transfers to a controller 8. The controller correct the clock 10 at this time. This polling from the master station as to time, is performed all at once at all the terminals. Though the clock is provided independently in the terminal, the time precision of the internal clock is allowed to lower by setting the polling interval of the time data short.
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