Patent ID: 6154859
Filing Date: 2000-11-28
Classification: H04L

Abstract:
A network abnormality monitor method in a network comprising a plurality of station units connected by a ring-like main data transmission line enabling circular transmission of communication data in digital form and adopting a master slave method as a communication method, wherein said plurality of station units are comprised of one master station unit operating as a master and slave station units operating as slaves, wherein said network comprises at least one sub data transmission line being provided separately from the main data transmission line for connecting said station units, and wherein each of said station units perform the steps of:executing monitor processing of monitoring a communication state in said network;executing abnormality determination processing of determining whether or not the communication state in said network is abnormal upon reception of a monitor processing result; andwhen it is determined that the communication state in said network is abnormal as a result of the abnormality determination processing, executing abnormality occurrence notification processing of sending abnormality occurrence information indicating abnormality occurrence and an abnormality occurrence point to said master station unit through the sub data transmission line.