PURPOSE: To prevent the lowering of the communication throughput of a communica tion processor accompanying the gathering processing of log data by letting the commu nication processors of both operating system and standby system perform the gathering processing of the log data.
CONSTITUTION: Dual communication processors IA transmit communication data to a transmission line 2 and receive reception data inputted from a reception line 3 in the case of being set to the operating system. Also, the communication processor IA is provided with a log data gathering means 11A for inputting transmission/ reception data and outputting them by a log data gathering instruction and a log data processing means 12A for storing the transmission/reception data outputted by the log data gathering means 11A in a log data storage part 6. A transmission switching part 4 switches the transmission data from the operating system communication processor to the transmission line 2 and a reception switching part 5 switches the reception data so as to be received in the operating system communication processor. When log data gathering is instructed to the communication processor 1A of the standby system, since the communication processor 1A of the standby system performs a log data gathering processing and the communication processor of the throughput of the communication processing is not lowered.
