When the line sends a short circuit or earth fault message, the fault line from the substation exit to the point of failure of all fault indicators will be tripped or flashing.
 
The fault indicators on no-faulty Line and the non-fault branch, and the fault indicators after the faulty location will be no active. In this way,  the operator
from the substation goes along the fault line to locate the sector between last tripped fault indicator and the first inactive fault indicators, so as to quickly confirm the faulty section, branch and location.
There is no longer need to inspect the line to find fault location at sight by use of a  fault indicator with communication function.  With the cooperation of fault indicator and communication terminal and software, the monitoring station or mobile phone can receive the faulty information to find the faulty location within 3-5 minutes.