US 6,188,494 B1Granted

Fiber-optic transceiver for long distance data communications

AssigneeSchweitzer Engineering Laboratories, Inc.

InventorTimothy M. Minteer

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Abstract

A fiber-optic transceiver receives from and transmits to an associated electronic terminal device, such as a protective relay, digital data signals. Fiber-optic transceivers can be positioned at opposite ends of a connecting fiber-optic line. Power for each transceiver is obtained from its associated electronic device. The transceiver includes a transmit section, a receive section, a handshake section to provide feedback of control signals which may be required by the associated electronic terminal device, and a voltage supply section. A particular optical coding arrangement is used to convert the digital data signal from the terminal device to a series of optical pulses, wherein a pair of optical pulses represents a rising edge of the digital data signal from the electronic device, while a single pulse represents the falling edge of the data signal. Additional pairs of pulses and single pulses may follow the initial one, depending upon the length of the high and/or low portions of the data signal. A receive portion of the transceiver receives a series of optical pulses from the fiber-optic cable, recognizes the double and single optical pulses, and reconstructs a digital data signal therefrom.

Claims17

Dependent claims

A fiber-optic transceiver for asynchronous communication of data, comprising:

means for receiving from a terminal device a digital data signal having high states and low states;
means for generating a series of optical pulses from the data signal, without a clock signal, said optical pulses operating between first and second states, wherein a first optical pulse arrangement represents and occurs in response to a rising edge of the data signal and operates between said first and second states and a second optical pulse arrangement represents and occurs in response to a falling edge of the data signal and also operates between said first and second states, the first and second pulse arrangements, respectively, occurring repetitively at preselected times during said high and low states if the high and low states exceed a preselected length of time;
means for transmitting said series of optical pulses along a fiber-optic cable;
means for receiving a transmitted series of optical pulses from a fiber-optic cable and for recognizing first and second pulse arrangements in the series of optical pulses and reconstructing a digital data signal having high and low states therefrom, the reconstructed digital data signal being a substantial replication of the digital data signal from which the series of optical pulses were generated;
and
means for providing said reconstructed digital data signal to the terminal device.

3 more elements

Dependencies are inferred from the claim text.