The signal flow analysis method first divides the whole network into several OMSs, judges the section of the fault, and then judges whether the direction of the fault is one-way or two-way, and…

The signal flow analysis method first divides the whole network into several OMSs, judges the section of the fault, and then judges whether the direction of the fault is one-way or two-way, and finally locates the fault along the direction of the signal flow from front to back according to the fault information.