Fail safe repeater for fiber optic bus distribution system

• US 4,581,770 A
• Filed: 12/19/1983
• Issued: 04/08/1986
• Est. Priority Date: 12/19/1983
• Status: Expired due to Fees

• Current Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Original Assignee: RCA Corporation (General Electric Company)
• Inventors: Haworth, Robert F.
• Primary Examiner(s): Orsino, Jr., Joseph A.
• Assistant Examiner(s): Greer, Timothy K.
• Application Number:
  US06/562,516
• Time in Patent Office: 841 Days
• Field of Search: 370/1, 370/16, 370/75, 370/97, 370/85, 340/825.05, 179/175.3 S, 179/175.31 R, 455/601, 455/606, 455/607, 455/612, 455/8, 455/613
• US Class Current: 398/3
• CPC Class Codes: H04B 10/29 Repeaters

Abstract

Redundant repeaters are positioned along a fiber optic (FO) bus of a data transmission system, each comprising a first star coupler having an input port connected to the FO bus and having N output ports, a second star coupler having N input ports and an output port connected to the FO bus, first and second repeaters each comprising, in tandem, a receiver whose input is connected to an output port of the first star coupler and a transmitter whose output is connected to an input port of the second star coupler. A fiber optic coupler is connected between a third output port of the first star coupler and a third input port of the second star coupler. A first detector responds to the output signals of the first and second transmitters to identify the existence and the type of failure in the two repeaters.

Claims

1. A redundant repeater connected into a transmission system employing a fiber optic (FO) bus and comprising:

a first star coupler having an input port connected to said FO bus and N output ports;

a second star coupler having N input ports and an output port connected to said FO bus;

a first continuously energized repeater comprising a first receiver and a first transmitter connected in series arrangement between a first output port of said first star coupler and a first input port of said second star coupler to amplify signals supplied to the input port of said first star coupler;

a second continuously energized repeater comprising a second receiver and a second transmitter connected in series arrangement between a second output port of said first star coupler and a second input port of said second star coupler to amplify signals supplied to said input port of said first star coupler;

a fiber optic coupling means connected between a third output port of said first star coupler and a third input port of said second star coupler for coupling signals supplied to said input port of said first star coupler without change to said output port of said second star coupler;

first detecting means responsive to output signals of said first and second transmitters to identify a failure of either of said repeaters;

second detecting means responsive to output signals of said first and second receivers of said repeaters to identify a failure of either of said receivers; and

logic means including switching means responsive to said first and second detecting means when only the receiver of one repeater and only the transmitter of the other repeater are in a failed condition to connect the output of the non-failed receiver to the input of the non-failed transmitter.

2. A redundant repeater as in claim 1 and further comprising:

logic means responsive to the identification of a single failed receiver, a single failed transmitter, or the combination of a single failed receiver in one repeater and a single failed transmitter in the other repeater to generate encoded signals identifying such specific failures; and

means including a non-failed transmitter for supplying said encoded signals to said FO bus for transmission thereon.

3. A redundant repeater as in claim 1 and further comprising logic means responsive to the failure of both of said first and second receivers to generate a signal identifying such a failure.

4. In a transmission system employing a fiber optic (FO) bus a redundant repeater positioned along said FO bus and comprising:

a first optical coupling means having an input terminal connected to a first end of said FO bus and having N output terminals;

a second optical coupling means having an output terminal connected to a second open end of said FO bus and having N input terminals;

first and second repeaters each comprising, in tandem, a receiver and a transmitter connected between a output terminal of said first optical coupling means and an input terminal of said second optical coupling means; and

first detecting means responsive to output signals generated by said transmitters of said first and second repeaters to identify a failure of either of said transmitters;

second detecting means responsive to the output signals of said receivers of said repeater to identify a failure of either of said receivers; and

logic means including switching means responsive to said first and second detecting means when only the receiver of said first repeater and only the transmitter of said second repeater are in a failed condition to connect the output of the non-failed receiver to the input of the non-failed transmitter.

5. A redundant repeater as in claim 4 and further comprising;

logic means responsive to the identification of a single failed receiver, a single failed transmitter, or the combination of a single failed receiver in one repeater and a single failed transmitter in the other repeater to generate encoded signals identifying such specific failures; and

means including a non-failed transmitter for supplying said encoded signals to said FO bus for transmission thereon.

6. A redundant repeater as in claim 4 and further comprising logic means responsive to the failure of both receivers to generate a signal identifying such a failure.

7. A redundant repeater arrangement adapted for use in a fiber optic transmission system, said arrangement comprising:

a first optical star coupler including an input port and at least first and second output ports;

a second optical star coupler including an output port and first and second input ports;

a first continuously energized repeater including a first receiver having an input port coupled to said first output port of said first star coupler and also having an output terminal, and a first transmitter having an output port coupled to said first input port of said second star coupler and also having an input terminal, and also including a first single input multiple output switch having its single input terminal coupled to said output terminal of said first receiver and a first of its output terminals coupled to a first input terminal of a first OR gate, the output of which is coupled to said input terminal of said first transmitter.

a second continuously energized repeater including a second receiver having an input port coupled to said second output port of said first star coupler and also having an output terminal, and a second transmitter having an output port coupled to said second input port of said second star coupler and also having an input multiple output switch having its single input terminal coupled to said output terminal of said second receiver and a first of its output terminals coupled to a first input of a second OR gate, the output of which is coupled to said input terminal of said second transmitter;

failure detecting means coupled to said first and second repeaters for sensing the simultaneous failure of said first receiver and second transmitter concurrent with non-failure of said second receiver and said first transmitter and for operating said second switch to couple signal from said output terminal of said second receiver to a second output terminal of said second switch; and

means for coupling said second output terminal of said second switch to a second input terminal of said first OR gate for coupling signals from said non-failed second receiver to said non-failed first transmitter.