PURPOSE:To check the quality of a signal input material in an extremely simple and accurate way by actuating said input material to judge whether the voltage change is produced or not. CONSTITUTION:When a check mode switch plug of a lead wire led from a control part 19 is pulled out to produce the disconnection, the part 19 is set under an input check mode. Under such conditions, various switches 14, 16, 18 and 37 are turned on and off together with position control given to various sensors 39, 40, 41 and 44, the drive applied to those sensor shafts, etc. Thus a signal input material is actuated. Based on this actuation of the signal input material, the part 19 checks each time whether the voltage change is produced or not. Thus it is judged that the relevant signal input member is normal as long as the voltage change is confirmed. Then a buzzer type alarm provided to a control panel is actuated.
