| 摘要 |
PROBLEM TO BE SOLVED: To shorten the using time of a communication line to the minimum degree with the remaining time to a service starting time being notified to a subscriber continuously. SOLUTION: A service starting time is transmitted from a master device 1 to a slave device 2. In the slave device 2, the time difference between the received service starting time and the standard time, i.e. the remaining time, is operated in a reduction function part 23, the time difference is down-counted in a down-counting part 24 at the specified divided intervals and the down- counted value is continuously reported from a reporting function part 25 to a subscriber in this constitution. |
