Abstract: A fiber optic multiplexer and demultiplexer system uses programmable controllers to coordinate the acquisition of switch and sensor state information, to control fiber optic sources, to control fiber optic detectors, to format output, and to perform all timing functions and error correction. The system includes a multiplexer which has an input interface that presents groups of one-bit state information to a storage latch, the number of latches depends on the number of states to be transmitted. A programmable controller selects each latch, reads the state information and drives an optical source to send the information in a multiplexed format. The system also includes a demultiplexer which has a programmable controller that monitors an optical detector for an incoming optical signal. The controller decodes the signal, checks the data for errors, and sends the data to the proper output storage latch.

Abstract: A multiple channel driver for fiber optic devices includes a source and an associated detector for each channel having processing circuitry and the power for the sources common to all channels. The system includes a master controller which has a precise time base to sequentially access each channel. The master controller is used to coordinate the multiple channels in a selected sequential manner. Synchronization of the channels avoids crosstalk since only one channel is on at a time. Power requirements are reduced since only one source is on at a time. The controller measures the background noise level, and subtracts it from the received signal. If the background noise level is too high, or the received signal too low, the master controller provides a warning. The controller also considers the signal history as an aid in locking onto signals and providing cleaner switching.

Abstract: A head unit for remote light sensing utilizes a lens secured in one end opening proximate to the light to be sensed, as well as a passive light source having a radiating end and a passive light collector having a receiving end, the source and collector being secured in a second opening such that both are substantially adjacent to the focal point of the lens and to each other such that the lens substantially collimates light emitted from the passive light source, and focuses received external collimated light at the focal point of the lens. The passive light source and passive light collector are respectively connectible to a powered light source and a photoelectric detector.