| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a system for synchronizing time of day or the like, which can synchronize appropriately the time of day of each device on a network. <P>SOLUTION: In figure(b), a reference device 1 measures a reference time HO and transmits it to a subordinate device 2, and meanwhile, the subordinate device 2 sets the reference time HO received and sends a reply of response to the reference device 1. In figure(c), after computing a communication time α, the reference device 1 transmits an instruction for advancing time only by α/2 to the subordinate device 2, and meanwhile, the subordinate device 2 measures a time H2 being advanced and sends an estimated time which is obtained by adding α/2 to the time H2, back to the reference device 1. Then, the reference device 1 obtains a time difference ΔT between the time measured at the receiving time and the estimated time being sent back. In the case the time difference ΔT is present, as shown in figure(d), the reference device 1 transmits a set time which is obtained by adding a communication time β1 to a reference time H3, to the subordinate device 2, and meanwhile, the subordinate device 2 receives the set time and sets it to its timing section. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
