Abstract: An endoscope system (20) comprising an endoscope (22) with light source (28). A light generated by the light source is supplied to the endoscope by a fiber optic cable (46). The cable in addition to including an optically transmissive core (50), includes two conductors (62) that are not in direct electrical contact with each other. Contacts (70, 71) in a plug attached to one end of the cable attach the conductors to circuitry internal to the light source. Contacts (80, 84) in a plug at the opposed end of the cable also provide at the opposed end of the cable. When the cable is attached to the endoscope, contacts (80, 84) are shorted together so as to complete the circuit established therebetween. This circuit completion state is monitor by the light source. When the cable is disconnected from the endoscope this connection is broken. This disconnect state is recognized by the light source as an endoscope-disconnected condition.