Fiber optic data link module with built-in link diagnostics
AssigneeInternational Business Machines Corporation
InventorsDaniel M. Kuchta, Albert X. Widmer
Life of this patent
Estimating the term…
Abstract
A diagnostic system utilizes a monitor photodiode and a laser from a fiber optic data link transceiver to perform diagnostic measurements on the fiber optic data link. The diagnostic system includes a multiplexer connected between the encoder and the laser driver of the fiber optic data link. The multiplexer is controlled by a normal op/test mode selector and receives a pulse or pattern for the test mode from a pulse/pattern generator. A signal from the monitor photodiode flows into a pulse/pattern detection circuit which signals a register if a pattern is found. After a reflected pulse is detected, the register captures a count and forwards it to a service processor or system to be analyzed.
Claims17
A fiber optic data link module with built-in link diagnostics, comprising:
- a diagnostic system that uses signals from a laser diode and a monitor photodiode of a fiber optic transmitter system to perform diagnostics of said fiber optic transmitter system by receiving digital data and by performing processing to detect a reflected test signal and to compute a roundtrip time of the reflected test signal to determine one of a fault location and link length,
- wherein said diagnostic system comprises:
- a multiplexer capable of connecting between an encoder and a serializer of said fiber optic transmitter system;
- a counter capable of connecting to a phase locked loop of said fiber optic transmitter system;
- a pulse/pattern generator connected to said multiplexer;
- a normal op/test mode selector connected to said multiplexer;
- a test controller connected to said normal op/test mode selector, said counter and said pulse/pattern generator;
- a register connected to said counter;
- and
- a pulse/pattern detector connected to said test controller and capable of connecting to said phase locked loop and said monitor photodiode of said fiber optic transmitter system.
A method of performing link diagnostics on a fiber optic data link comprising the steps of:
- connecting a diagnostic system to a fiber optic transmitter system;
- raising a test mode select input to an enabled voltage;
- sending a trigger pulse from a test controller to trigger a pulse/pattern generator to produce a pulse/pattern;
- resetting a counter to begin counting;
- monitoring with a pulse/pattern detector, a received signal for a received pulse/pattern;
- sending a trigger to a register;
- capturing at said register a current count;
- and
- transmitting said current count out of said diagnostic system, and further comprising the steps of:
- inserting a multiplexer at an output of a receiver connected to said fiber optic transmitter system;
- and
- selecting by said multiplexer between decoded data of said receiver and a count output from said register.
A fiber optic data link module with built-in link diagnostics, comprising:
- a fiber optic transmitter system comprising:
- an encoder;
- a serializer connected to said encoder;
- a phase-locked loop connected to said serializer;
- a laser driver connected to said serializer;
- a laser diode connected to said laser driver;
- and
- a monitor photodiode connected to said laser driver;
- and
- a diagnostic system connected to said fiber optic transmitter system that uses said laser diode and said monitor photodiode from said fiber optic transmitter system to perform diagnostics by receiving digital data and by performing processing to detect a reflected test signal and to compute a roundtrip time of the reflected test signal to determine one of a fault location and a link length, wherein said diagnostic system comprises:
- a multiplexer connected between said encoder and said serializer of said fiber optic transmitter system;
- a counter connected to said phase locked loop of said fiber optic transmitter system;
- a pulse/pattern generator connected to said phase locked loop and said multiplexer;
- a normal op/test mode selector connected to said multiplexer;
- a test controller connected to normal op/test mode selector, said counter and said pulse/pattern generator;
- a register connected to said phase locked loop and said counter;
- and
- a pulse/pattern detector connected to said phase locked loop, said test controller and said monitor photodiode of said fiber optic transmitter system.
Dependencies are inferred from the claim text.