PURPOSE: To simplify a fault processing program by sending a 're-rising' command to a secondary station having a fault from a centralized monitoring device to executes the restoration of the relevant secondary station.

CONSTITUTION: When a fault such as power interruption or CPU stop takes place in an optional secondary station, a centralized monitoring device 1 executes a prescribed fault processing according to a program in a memory 12 and an alarm is raised by an output device 15 via an interface 11 to raise attention to an operator and to urge confirmation. When the confirmation by the operator is finished, a 're-rising' command is sent to a secondary station having a fault from the host CPU 13 to link the secondary station to the transmission system again. Thus, the transmission processing program of the primary station is simplified.