| 摘要 |
<p>It is possible to reduce the average intensity of a leak electric field from a power line by stopping a signal output from a PLC device when no data to be transmitted exists. A PLC modem (1) includes a PLC-IF (10) and a modem control unit (16) connected to the power line (3). When the state that there is no transmission data to be transmitted to the PLC-IF (10) or no reception data to be received via the PLC-IF (10) continues for a predetermined halt judgment period, the modem control unit (16) shifts to a halt state in which no signal is outputted from the PLC-IF (10). Furthermore, in the halt state, if the amount of data to be transmitted to the PLC-IF (10) exceeds a predetermined start threshold value or if the PLC-IF (10) has detected a reception of a start signal, the PLC modem (1) shifts to a normal state in which a signal is outputted from the PLC-IF (10). Furthermore, when the normal operation state is set in when the start threshold value is exceeded, the start signal is outputted to the PLC-IF (10).</p> |
