| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable highly accurate time synchronization even in transmitting a communication frame periodically. <P>SOLUTION: A network interface part (14) transmits a communication frame to a slave apparatus in a data transmission period at a predetermined interval and outputs a transmission completion notice when the transmission is completed. A clock (11) measures an output time of the transmission completion notice as a transmission completion time. A transmission completion time holding part (15) holds the transmission completion time. A transmission completion interval calculation part (13) calculates an output interval between the transmission completion notices from two transmission completion times. A time calculation part (17) estimates the transmission completion time in the next data transmission period based on the transmission completion time held in the transmission completion time holding part (15) and the output interval calculated by the transmission completion interval calculation part (13). A time information transmission part (16) generates a communication frame for time synchronization showing an estimation time. The network interface part (14) transmits the communication frame for time synchronization to the slave apparatus in the next data transmission period. <P>COPYRIGHT: (C)2012,JPO&INPIT |
