STATE MONITORING DEVICE, STATE MONITORING SYSTEM, AND TRAIN

In the related art, a system is not disclosed in which a predetermined location or position is automatically recorded regardless of any sensor information for preventive maintenance from characteristic sensor information that is generated at the predetermined location or section. There is provided a state-monitoring device that performs state monitoring of a vehicle based on a sensor signal and positional information of the vehicle, the state-monitoring device is configured to have a sensor signal detecting portion, a sensor signal threshold determination processing portion, a sensor signal threshold exceeding section management portion that inputs positional information of the vehicle and a determination result by the sensor signal threshold determination processing portion and measures the number of times that the threshold is exceeded within a predetermined section, and an automatic recording section management portion that determines whether or not the number of times that the threshold is exceeded within the predetermined section exceeds the predetermined number of times and sets the predetermined section as an automatic recording section in a case where the number of times that the threshold is exceeded exceeds the predetermined number of times.