| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a memory data sharing system in which stations can transmit and receive data to/from each other and which can continuously function even when a certain station fails to function or even when a failure occurs in a communication line. <P>SOLUTION: In this system, a specific station address value is set to each of stations, and each time is made to correspond to the address value of each station. All internal clocks (39) in the stations show the same time and circulates from a time Too to an upper limit time TM. When the internal clocks (39) show a time corresponding to the station address value of a certain station, data in memories (38) located at a memory address corresponding to the station address value is embedded in a packet (9) and transmitted to communication lines (33A and 33B). An allowable time error determination circuit (34) compares a calculated correct time of the internal clock of its own station with a time indicated by the internal clocks (39), and corrects the internal clocks (39) if the time indicated by the internal clocks (39) exceeds an allowable time error range. The system is provided with a plurality of the communication lines (33A and 33B), if a change in a bit showing a connection state to respective stations occurs, other communication lines (33B) is utilized. <P>COPYRIGHT: (C)2003,JPO |
