Abstract: An optical switch of the multiple push button type for producing a plurality of control signals includes a housing and at least two sliders disposed within the housing. The sliders move between an initial position and at least two other positions. A pair of stationary light shields are disposed between said sliders in spaced apart relation, each of the shields having a plurality of apertures. Light emitting means are disposed between the stationary light shields. Separate light responsive means are disposed adjacent to each of the sliders. A pair of moveable light shields, each disposed between one of the stationary light shields and one of the light responsive means, each has a plurality of apertures and each is movable in response to movement of a separate one of the sliders. Circuitry responds to output of the light responsive means to produce the foregoing control signals, such output being dependent upon the position of the sliders.

Abstract: An optical path degradation detecting device having a laser distance detector which uses a laser beam to detect the distance between two objects and which generates distance signals representative of the distance between the two objects. A first predetermined point signal is generated upon the distance signals being in a distance representative of a first predetermined distance or less, and a second predetermined point signal is generated upon the distance signals being in a distance representative of a second predetermined distance or less, wherein the second predetermined distance is less than the first predetermined distance. A fault signal is generated if the second predetermined point signal is generated within a predetermined time interval relative to the generation of the first predetermined point signal.

Abstract: A data transmission link is especially designed to meet new FCC regulations setting 5 KHz band widths for transmitting control signals to industrial systems. The new band width creates timing distortions which are overcome by inserting a new timing pulse into a data pulse stream. The center of that inserted timing pulse is taken as an axis of reference for retiming each pulse in the data pulse stream so that the fluctuations of a time frame synchronizing pulse become irrelevant. The retiming process is repeated for each data time frame.