PURPOSE: To attain control and monitor with high efficiency and high reliability by providing a control monitor and a logging processing function of a common standby system to plural control monitors.

CONSTITUTION: A control monitor 33 is a common standby device for control monitors 30-32 and a common device 20 decides it for which of the monitors 30-32 the monitor 33 is used. The monitors 30-32 output fault signals Fa-Fc on the occurrence of a fault, the common device 20 receives a fault signal and when the device 33 is normal, the active/standby is selected automatically. When a subsystem of the communication equipment 10 generates a state change signal or an alarm signal, a monitor packet is sent. The common device 20 receives the monitor packet from a serial port SP20B and sends the packet from a port SP23B. When the device 30 detects the occurrence of a fault in the device 10, the device 30 generates a signal Aa. Each of the devices 30-33 is provided respectively with a logging processing section 40(41-43) and the status change of each communication equipment and the fault information are stored in the relevant processing sections 40-43.