BROKEN LINE DETECTOR IN LOCAL AREA NETWORK

摘要

PURPOSE:To detect accurately a disconnected part of a communication line interconnecting equipments while simplifying internal configuration of each equipment being a component of a LAN by using a circulation signal transmission means and a fault detection means so as to detect the presence of a disconnected line of the communication line. CONSTITUTION:A circulation signal transmission means allows a communication means to send a circulati signal returned to the equipment circulated through each equipment being component of the LAN at once at least within a prescribed period of time in an either equipment direction. Then a fault detection means detects it as a fault when the circulation signal is not detected by the communication means within a prescribed period of time. When the fault is detected, a notice command means sends a command signal for notice command to a drive means in each equipment being a component of the LAN in an either equipment direction. Upon the receipt of the notice command, the drive means in each equipment drives a fault notice means provided to each equipment to inform a fault of the communication line.