There is provided a controlling communication system which includes a control device for transmitting a control signal, an object-side communication device mounted on a controlled object for receiving the control signal, and a drive control device for controlling the controlled object, and which can set a failsafe function of the object-side communication device using the control device, wherein a voltage reference value and a detection time reference value set by the control device are transmitted to the object-side communication device and are stored in a memory unit of the object-side communication device, and wherein the object-side communication device judges if the battery state meets a requirement for activating a failsafe function by referring to the voltage reference value and the detection time reference value stored in the memory unit.