PURPOSE: To increase the maintenanceability and reliability, by providing the collating section to collate respective control signals and the monitor signal selecting section to select the monitor signal with monitored control station side of a remote control device in duplex and suitably judging either of two system control signals is responsible when a failure is detected.

CONSTITUTION: Control signals C1∼Cn to controlled device 13 are given to either one of the systems which pass through a monitor control panel 2, control signal transmission section 3, control signal reception 8 and selector 12 as control signals Ca1∼Can, and pass through the monitor control panel 2, control signal transmission section 5, and control signal reception section 10 as control signals Cb1∼Cbn. The collation section 14 detects the difference of the control signal of the two systems and displays it on the monitor control panel 2. The monitor control station 1 controls the monitor signal selection sections 15, 16 of the monitored control station to transfer the controlled signals Ca1∼Can and Cb1∼Cbn to the control station 1 to discriminate the failure.