Abstract: An optical fiber security system includes an optical emitter connected to one end of an optical fiber and a detector connected to the other end. A random signal generator triggers the emitter to output a light pulse signal through the fiber. This generator also simultaneously triggers the detector to receive the light pulse signal. A comparator compares the light pulse signal that is received by the detector with an optimum reference to adjust and conform the emitter output with the reference. Also, a monitor determines whether a particular identifiable characteristic of the light pulse signal is within a predetermined range of values. Whenever there is not a simultaneous emission and detection of the light pulse signal, or whenever the light pulse characteristic is outside the predetermined range of values, the system alarms.

Abstract: A device is disclosed for extracting dissolved gases from oil in an electrical transformer and for analyzing those gases using a plurality of gas sensors, a signal processor, and a neural network.

Abstract: A security screen assembly comprises a screen of mesh material with an optical path formed from at least one optical fiber integrally interwoven with the screen material in a generally serpentine path. A light source or transmitter is coupled to the first end of the optical path while a suitable light detector is coupled to detect light emitted from the second end of the optical path. An interface unit connects the screen to a remote alarm control unit for activating an alarm if the detected light signal falls below a predetermined intensity.

Abstract: An underwater acoustic communication system provides an operator with adjable frequency diversity so that data rates may be tailored to specific multipath environments. Transmitted messages are sent with precursor transmission/reception synchronization data and transmission parameter data so that the receiving communication end will recognize when message data starts, tone length as-well-as the frequency diversity of the transmitted message. Timing is extracted from the data to compensate for Doppler shift.

Abstract: An improved telemetry system for transferring data signals to and from a plurality of serially-connected, addressable data ports. The telemetry system includes a plurality of serially-connected input/output (I/O) data ports; an output data line and an input data line serially-connecting the data ports; a clock signal generator for generating clock pulses and frame pulses for common system timing; and a clock line for carrying the clock pulses and frame pulses from the clock signal generator to the ports. Each data port contains an address circuit which determines when during each frame that port is enabled to transfer data an input shift register for loading data signals for transfer onto the input data line at a time indicated by a transfer signal provided by the address circuit; and an output shift register for temporarily storing output data signals received from the output data line immediately prior to the provision of the transfer signal by the address circuit.

Abstract: A telemetry system for transferring blocks of pulsed data signals to and from daisy chains of addressable data ports. The telemetry system includes a daisy chain of input data ports and a parallel daisy chain of output data ports; an output data line and an input data line each serially-connecting the data ports; a clock signal generator for generating square wave clock pulses for common system timing; and a clock line for carrying the clock pulses to the ports. Each data port contains an address circuit which determines when during each block of serially-transmitted data signals that port is enabled to transfer data independent of its physical location on the data line. Data signals are transmitted over the data lines during high-state intervals of the clock signal and control signals such as frame signals, are transmitted over the data lines during the low-state intervals of the clock signals.