Abstract: A fiber optic switching system for industrial control sensing applications includes a link monitoring capability for detecting faults in the fiber optic cable. Two transmitters of different wavelengths are coupled into a single fiber. The switch utilizes an optical filter which when inserted in the optical path blocks one wavelength of light but allows the other to pass through. The absence of all light in the switch output indicates a fault and the presence or absence of the filtered-out light is used to determine the switch state.

Abstract: A connector for coupling an optical cable including at least one optical fiber terminated in an optical contact to a phototransducer device is disclosed. A swivel member mounts the optical contact with a terminal end of the contact adjacent to an inner side of the swivel member. The swivel member is received within a connector body and is movable therein. A base member mounts the photo-transducer device with the photo-transducer accessible from an inner side of the base member. Mating surfaces are formed on the inner sides of the swivel and base members, to guide the terminal end of the contact and the photo-transducer device into alignment as the connector body is moved to a connected position adjacent to the base member. Biasing means between the connector body and the swivel member urges the swivel member toward the base member and allows the swivel member to align itself with the base member. Means are also provided for securing the connector body in the connected position.