A robot control system includes a control device for controlling a robot and a portable operating panel connected to the control device. The portable operating panel and at least one other device include contact points connected in series. The control device includes a reception circuit that can detect the opening of at least one of the contact points. The portable operating panel includes a smart device having a sensor. The contact point included in the portable operating panel is opened and closed in conjunction with a physical movement of a switch member attached to an exterior of the smart device. The sensor can detect a physical quantity that changes in conjunction with the physical movement of the switch member. The portable operating panel transmits, to the control device, a detection signal indicating the physical quantity detected by the sensor or information about the physical quantity.