| 摘要 |
The invention relates to a method of synchronizing clocks contained in a local network of bus type, such as Ethernet and a system of synchronizing clocks. In local networks of this kind a number of nodes are connected to a common data channel. The object of the invention is to obtain a method and a system of synchronizing the clocks which is more accurate than previous methods and systems, in which the synchronizing information is transmitted as common data packages in which the receiver of the synchronizing information does not know the instant of the data package generation. According to the invention a synchronizing message is transmitted from one node which has been chosen to be the master to all nodes, the master node inclusive. When receiving a synchronizing message the nodes read the clock state. Then the master node transmits a clock time message containing the master node clock state when it received the synchronizing message. The clock state indicated by the received clock time message is compared in the slave nodes with the clock states which have been read in the slave nodes. The clock states of the read clocks are compared with the received master clock state and the clock stats of the slave nodes are corrected in dependance on the outcome of the comparison. The clock synchronizing according to the above is suitable for, e.g., military applications. |
