| 摘要 |
PURPOSE:To reduce investments on the whole system by calibrating a clock device in a central-point installation by reception of standard time information, and calibrating other clock devices in remote-point installatios in sequence in accordance with the time information from said clock device, CONSTITUTION:The muP4 of a central-point installation 1 uses a time reader 7 to fetch time information obtained by means of a radio receiving unit 6, for calibrating a clock device 5. The muP4 fetches time information from the device 5 and produces a test signal and transmits the signal to public lines 3 via a transmitting-receiving unit 8 so that the signal is transferred to a predetermined remote-point installation 2. When a transmitting-receiving unit 12 receives the signal, a muP10 performs reception processing and then produces a test signal and transfers it to the installation 1 via the unit 12 and the lines 3. When the unit 8 receives the test signal, the muP4 computes the communication delay time and then computes time calibration data for transmission to the installation 2, and re-transfers the data to the installation 2 using a similar course. The muP10 fetches the time calibration data through a similar course and calibrates the time of the clock device 11. |
