System and method for fiber optic communication with safety-related alarm systems

• US 6,900,726 B2
• Filed: 09/12/2003
• Issued: 05/31/2005
• Est. Priority Date: 01/03/2003
• Status: Expired due to Fees

• Current Assignee: UTC Fire & Security Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Antronix Incorporated
• Inventors: Graves, Edwin
• Primary Examiner(s): Pope, Daryl C.
• Application Number:
  US10/660,960
• Publication Number:
  US 20040130445A1
• Time in Patent Office: 627 Days
• Field of Search: 340/531, 340/506, 340/507, 340/533, 340/693.6, 340/3.1
• US Class Current: 340/531
• CPC Class Codes: H04B 10/801 using optical interconnects, e.g. light coupled isolators, circuit board interconnections
• CPC Class Codes: H04B 10/85 Protection from unauthorised access, e.g. eavesdrop protection

Abstract

A system and method for monitoring and safety related systems (SRSs) in a Secure Compartmented Information Facility (SCIF) that addresses concerns for security of electronic emanations from equipment in the SCIF. A fiber optic link connects an optical receiver located within a SCIF and an optical transmitter located outside the SCIF. Alarm signals generated by an SRS located outside the SCIF are detected and sent to the optical receiver over the fiber optic link. The optical receiver converts the optical signals to electrical signals and directs the signals to alarm devices within the SCIF. Additionally, an audio signal generated at the location outside the SCIF is converted to an optical signal and then reconverted to an audio signal by the optical receiver for broadcast over a speaker located within the SCIF. A tone signal generated at the optical transmitter is continuously sent over the optical fiber link to the optical receiver and the SCIF speaker. The tone signal is monitored and any loss of the tone signal at the speaker causes an alarm signal to be returned to the optical transmitter located outside the SCIF. The optical receiver located within the SCIFF monitors an alarm device within the SCIFF for the presence of an alarm condition within the SCIFF. If an alarm condition within the SCIFF is detected, an alarm signal is sent over the fiber optic link to the optical transmitter located outside the SCIFF and directed to the SRS located outside the SCIFF.

Claims

1. A system for communicating an alarm condition between a secure compartmented information facility (SCIF) and a location outside the SCIF, the system comprising:

an optical transmitter located in the outside location;

an optical receiver located in the SCIF; and

an

fiber optic link connecting the optical transmitter and optical receiver, wherein;

the optical transmitter is adapted to send a continuous tone to the optical receiver; and

the optical receiver is adapted to detect the presence of the optical tone and to generate a trouble signal in the event the tone signal is not received.

2. The system for communicating an alarm condition between a SCIF and a location outside the SCIF as in claim 1, wherein the trouble signal is sent to the outside location.

3. The system for communicating an alarm condition between a SCIF and a location outside the SCIF as in claim 1, the system further comprising:

an inside safety-related system (SRS) located in the SCIF, wherein the inside SRS is adapted to generate an inside alarm condition signal in response to an event occurring in the SCIF;

an inside alarm signal generator located in the SCIF adapted to convert the inside alarm condition signal to an inside alarm optical signal; and

an outside alarm signal monitor located in the location outside the SCIF adapted to detect the presence of the inside alarm optical signal and to initiate a response in the event an inside alarm optical signal is present.

4. The system for communicating an alarm condition between a SCIF and a location outside the SCIF as in claim 3, wherein the inside SRS is selected from the group consisting of a fire detection system, a smoke detection system, an intrusion detection system, a biohazard release detection system, a fire suppressant release system, and a chemical release detection system.

5. The system for communicating an alarm condition between a SCIF and a location outside the SCIF as in claim 3 further comprising:

an outside SRS, wherein the outside SRS is adapted to generate an outside alarm condition signal in response to an event occurring in the location outside the SCIF; and

an outside alarm signal generator located outside the SCIF adapted to convert the outside alarm condition signal to an outside alarm optical signal; and

an inside alarm signal monitor located inside the SCIF adapted to detect the presence of the outside alarm optical signal and to initiate a response in the event an outside alarm optical signal is present.

6. The system for communicating an alarm condition between a SCIF and a location outside the SCIF as in claim 5, wherein the outside SRS is selected from the group consisting of a fire detection system, a smoke detection system, an intrusion detection system, a biohazard release detection system, a fire suppressant release system, and a chemical release detection system.

7. The system for communicating an alarm condition between a SCIF and a location outside the SCIF as in claim 5 wherein the outside alarm condition signal is an audio signal delivered to an outside speaker, and wherein the outside alarm signal monitor response in the event that an outside alarm optical signal is present comprises converting the outside alarm optical signal to an audio signal and sending the audio signal to the SCIF speaker.

8. A method for communicating an alarm condition between a secure compartmented information facility (SCIF) and a location outside the SCIF, the method comprising:

sending a tone signal from an optical transmitter located in the outside location connected via a fiber optic link to an optical receiver located in the SCIF; and

monitoring the reception of the tone signal by the optical receiver;

making a determination that the optical receiver is not receiving the tone signal; and

in the event the optical receiver is not receiving the tone signal, generating a trouble signal.

9. The method for communicating an alarm condition between a SCIF and a location outside the SCIF as in claim 8, the method further comprising:

generating an inside alarm condition signal in response to an event occurring in the SCIF;

converting the inside alarm condition signal to an inside alarm optical signal;

determining the presence of the inside alarm optical signal at the location outside the SCIF; and

initiating a response in the event that an inside alarm optical signal is present.

10. The method for communicating an alarm condition between a SCIF and a location outside the SCIF as in claim 9 further comprising:

generating an outside alarm condition signal in response to an event occurring in the location outside the SCIF;

converting the outside alarm signal to an outside alarm optical signal;

determining the presence of the outside alarm optical signal within the SCIF; and

initiating a response in the event that an outside alarm optical signal is present.

11. The method for communicating an alarm condition between a SCIF and a location outside the SCIF as in claim 10, wherein the outside alarm condition signal is an audio signal delivered to an outside speaker, and wherein initiating a response in the event that an outside alarm optical signal is present comprises converting the outside alarm optical signal to an audio signal and sending the audio signal to SCIF speaker.