ROBOT MONITORING SYSTEM, MONITORING DEVICE, METHOD FOR CONTROLLING MONITORING DEVICE, AND NON-TRANSITORY TANGIBLE STORAGE MEDIUM

A monitoring device includes a storage, a controller, and a communication module. The storage stores a table in which a series of operation positions to which a monitoring target of a robot moves and time information regarding a timing when the monitoring target is positioned at each of the operation positions are associated with each other. The controller executes a process of determining an operational abnormality of the robot by comparing an operation position of the monitoring target acquired from the robot with an operation position of the monitoring target based on a captured image from a camera, and a process of determining an operational abnormality of the robot by comparing a timing when the operation position has been acquired from the robot with a timing based on the time information associated with the operation position in the table.