| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a technique that is able to establish communication between devices more reliably than the prior art even at the time of power saving mode.SOLUTION: An upper side device comprises a control unit that transmits a monitoring signal for monitoring the operation of a lower side device during a power saving mode to the lower side device at a constant time interval. The lower side device includes: a setting unit that measures an elapsed time after transition to the power saving mode, and based on the elapsed time, sets the operation period and stop period of the lower side device alternately; and a control unit that repeats the operation and stop of the lower side device alternately depending on the setting by the setting unit during the power saving mode. This setting unit adjusts start timing of the operation period and stop period on the basis of reception timing of the monitoring signal.</p> |
