Patent Publication Number: US-2007115112-A1

Title: Supplemental fire alerting system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of U.S. Provisional Application No. 60/736,536 filed on Nov. 14, 2005. The disclosure of the above application is incorporated herein by reference. 
    
    
     FIELD  
      The present invention relates to fire alarm systems for persons with disabilities.  
     BACKGROUND  
      The American Disabilities Act (ADA) prohibits discrimination based on disability and therefore the ADA requires that public facilities provide assistance to persons who are disabled. Many public facilities such as hotels and motels find that making existing buildings compliant with the ADA is expensive and complex. For example, a hotel with a fire alarm system installed prior to the ADA becoming effective may be required to reconfigure the fire alarm system or add an auxiliary system. It would be desirable to implement a supplemental alerting system that complements an existing fire alarm system.  
     SUMMARY OF THE INVENTION  
      In view of the foregoing, a supplemental alerting system for a fire alarm system is provided. An exemplary system comprises an alarm control device that generates a fire alarm code signal based on detecting an alarm mode of a fire alarm system. A power line notification appliance (PLNA) generates at least one of a PLNA audible and PLNA visual fire alarm based on the fire alarm code signal. The alarm mode of the fire alarm system may be indicated by a voltage polarity reversal of a fire alarm control signal transmitted from the fire alarm system.  
      In other features, the system further comprises main power supply lines that power and electrically connect the alarm control device and the PLNA. The alarm control device and the PLNA communicate based on spread spectrum technology. The PLNA generates at least one of the audible and visual alarms until the active fire alarm control signal ceases. The alarm control device transitions to a supervisory mode after the fire alarm system receives a manual reset by an operator of the fire alarm system.  
      In other features, the alarm control device selectively polls the PLNA by transmitting an acknowledge command to the PLNA based on an encoded address of the PLNA and the PLNA transmits an acknowledgement response when the PLNA respectively receives and processes the acknowledge command. The alarm control device retransmits the acknowledge command to the PLNA when the PLNA fails to transmit the acknowledgement response. The alarm control device indicates a fault condition when the PLNA fails to transmit the acknowledgement response after the alarm control device transmits a pre-selected number (e.g., three) of consecutive acknowledge commands.  
      In other features, the alarm control device illuminates a fault indicator that corresponds to the PLNA and/or activates an audible alarm when the PLNA fails to transmit the acknowledgement response after the alarm control device transmits the pre-selected number of consecutive acknowledge commands. The acknowledge command includes an encoded address of the PLNA and an all alarm address.  
      In other features, the PLNA includes non-emergency alarm indicators for non-fire events such as the telephone. The PLNA illuminates a non-emergency PLNA alarm indicator based on receiving a non-emergency alarm notification signal from a RF transmitter. The RF transmitter generates the non-emergency notification signal based on a status change of a device such as a phone associated with the RF transmitter.  
      Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for the purpose of illustration only and are not intended to limit the scope of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
       FIG. 1  is a functional block diagram of a supplemental fire alerting system;  
       FIG. 2  illustrates an alarm control device of the supplemental alerting system;  
       FIG. 3  illustrates an alarm control device panel of the supplemental alerting system;  
       FIG. 4  is a functional block diagram of an exemplary room implementing the supplemental alerting system;  
       FIG. 5  is a functional block diagram of a plurality of exemplary rooms implementing the supplemental alerting system;  
       FIG. 6A  is a side view of a power line notification appliance of the supplemental alerting system;  
       FIG. 6B  is a front view of the power line notification appliance of the supplemental alerting system; and  
       FIG. 7  is a flow diagram for operating the supplemental alerting system. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers are used in the drawings to identify similar elements. As used herein, the term module, circuit and/or device refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure.  
      Referring to  FIG. 1 , the supplemental alerting system  10  includes an alarm control device (ACD)  12 , a fire control panel  14 , and a plurality of power line notification appliances (PLNAs),  16 - 1 ,  16 - 2 , . . . , and  16 - n,  referred to collectively as PLNAs  16 . The ACD  12  includes an ACD panel  18  that interfaces with the fire control panel  14  and the PLNAs  16 . The ACD  12  also includes a low current opto-isolator (not shown) that monitors a 24 direct current voltage (VDC) signal generated by the fire control panel  14 . The ACD  12  communicates with the fire control panel  14  via a standard two-wire interface circuit  20 . In the present implementation, the two-wire interface circuit  20  draws less than 1 milliampere (mA) of current during an alarm mode and approximately 10 microamperes of current during a supervisory mode.  
      The ACD  12  communicates with the PLNAs  16  via 120 alternating current voltage (VAC) main power lines (mains)  21  using various forms of VAC power line communication such as spread spectrum technology. Spread spectrum technology enables reliable communication between the ACD  12  and each of the PLNAs  16  based in part on a limited susceptibility to electrical power line noise. Additionally, spread spectrum signals typically do not interfere with the operation of various other devices (not shown) of an associated fire alarm system. The 120 VAC mains  21  also supply the ACD  12  with power. The ACD  12  may also include an ACD rechargeable backup battery  22  that provides power in the event of a power transmission loss from the 120 VAC mains  21  to the ACD  12 .  
      During alarm mode operation, the ACD  12  sends a fire alarm code signal, or an all alarm address, to each of the PLNAs  16  when the ACD  12  detects an alarm mode such as a voltage polarity reversal of the 24 VDC fire alarm control signal generated by the fire control panel  14 . The fire alarm code signal may include, but is not limited to, a direct sequence spread spectrum signal that operates over a wide frequency range. In the present implementation, the fire alarm code signal indicates a fire alarm.  
      The ACD  12  selectively transmits a fire alarm code signal via the 120 VAC mains  21  to the PLNAs  16  based on encoded addresses assigned to each of the PLNAs  16 . Each of the PLNAs  16  stores a respective encoded address in non-volatile memory such as flash memory. In the present implementation, each encoded address includes an 8 bit value, though other implementations are contemplated.  
      The respective PLNAs  16  generate an emergency stimulus including, but not limited to, an audible and/or visual alarm based on receiving the fire alarm code signal from the ACD  12 . Each of the PLNAs  16  generates the emergency stimulus for a limited duration (e.g., ten seconds) based on receiving a fire alarm code signal. The ACD  12  periodically retransmits the fire alarm code signal if the ACD  12  continues to detect the alarm mode after a time interval (e.g., every six seconds). In other words, the PLNAs  16  continuously generate the emergency stimulus as long as the ACD  12  detects the alarm mode (e.g., voltage polarity reversal). In various implementations, the ACD  12  can transmit distinct danger alarm code signals to each of the PLNAs  16 , respectively, based on the encoded addresses assigned to each of the PLNAs  16 . The danger alarm code signals indicate a sequence and/or duration of time for activating the emergency stimulus of each of the PLNAs  16 . The ACD  12  generates the danger alarm code signals based on the data transmitted to the ACD  12  from at least one of the PLNAs  16 . The data can include, but is not limited to, information indicative of conditions (e.g. temperature and/or oxygen levels) within a detection range of the PLNA  16 .  
      To return the supplemental alerting system  10  to a supervisory mode operation, a user/operator may manually reset the fire control panel  14 . The fire alarm code signal maintains priority over various other control and/or data signals transmitted during the alarm and supervisory modes of the supplemental alerting system  10 .  
      During supervisory mode operation, the ACD  12  receives operational power from the 120 VAC mains  21  and controls each of the PLNAs  16 . The ACD  12  periodically polls each of the PLNAs  16  to ensure proper communication by transmitting an acknowledge command signal to each of the PLNAs  16  individually based on the respective encoded addresses of each of the PLNAs  16 . In the present implementation, the ACD  12  transmits the acknowledge command twice per time interval to each of the PLNAs  16  based on a sequential order of the encoded addresses of the PLNAs  16 . The acknowledge command can include, but is not limited to, an encoded address of the respective PLNA  16 . Each of the PLNAs  16  respectively transmits an acknowledgement response (e.g., two bits) based on receiving and decoding an acknowledge command. Additionally, each of the PLNAs  16  that receives and decodes the acknowledge command may illuminate an operational light indicating proper operation (e.g. flashing green light). Those skilled in the art will appreciate that various other types of acknowledge commands and/or acknowledgement responses are contemplated.  
      If at least one of the PLNAs  16  fails to transmit an acknowledgement response, the ACD  12  retransmits the acknowledge command to the respective PLNA  16 . A pre-selected number (e.g., three) of consecutive failures by a particular PLNA  16  to respond to the acknowledge command indicates a fault condition. Additionally, if the PLNA  16  fails to receive and decode the acknowledge command within a receiving window (e.g., two minutes), a fault condition exists.  
      During a fault condition, the ACD  12  enables an audible device and/or illuminates an ACD alarm indicator (e.g., a red light) that corresponds to the PLNA  16  experiencing a fault condition (failed PLNA). In various embodiments, the failed PLNA may also activate a fault stimulus until proper communication with the ACD  12  is restored. As the ACD  12  continues to sequentially poll each of the PLNAs  16 , the ACD  12  also continues to poll the failed PLNA  16 . If the ACD  12  establishes communication with the failed PLNA  16 , the ACD  12  resets the audible device and/or extinguishes the light corresponding to the failed PLNA  16 . In the present implementation, all PLNAs  16  remain in the fault condition until proper operation of the failed PLNA is restored. The fault condition can result from various failures including, but not limited to, communication failures, a short circuit within the 120 VAC mains  21 , an open circuit within the 120 VAC mains  21 , interference, failure of a PLNA  16 , failure of the ACD  12 , and/or failure of a back up battery  22 .  
      Referring now to  FIGS. 2 and 3 , the ACD  12  and ACD panel  18  are shown in more detail. The ACD  12  includes a protective (e.g., steel) enclosure  24  having a preferably hinged door  26  that provides access to the ACD panel  18 . The hinged door  26  includes a transparent front panel  28  exposing the ACD panel  18 . The ACD panel  18  includes the ACD rechargeable backup battery  22 , an array of ACD alarm indicators  30 , referred to individually as an ACD alarm indicator, a terminal block  32 , an alarm test input  34 , and an audible alarm device  36 .  
      The array of ACD alarm indicators  30  is visible to a user/operator of the ACD  12  via the front panel  28 . Each ACD alarm indicator of the array of ACD alarm indicators  30  corresponds to one of the PLNAs  16 . Each of the PLNAs  16  corresponds to a channel associated with a respective operating location (e.g., room, bathroom, or office). The ACD panel  18  includes provisions to identify each indicator based on a channel and location.  
      The termination block  32  provides terminations for wires (not shown) leading to the fire control panel  14  and for a dry NPFA approved relay contact. The relay contacts close when a fault condition is recorded by the ACD  12  thereby informing a fire control system that the supplemental alerting system  10  is in a fault condition. Additionally, the audible alarm device  36  activates when the supplemental alerting system  10  experiences a fault condition. Upon activating the alarm test input  34 , the ACD  12  transmits a fire alarm code signal to each of the PLNAs  16  thereby initiating the alarm mode operation. The ACD  12  returns to the supervisory mode operation upon deactivation of the alarm test input. In the present implementation, the alarm test input includes a pushbutton though other implementations are contemplated such as a touchpad.  
      As discussed above, the ACD rechargeable battery  22  (e.g., nickel-cadmium battery) is optionally attached to the ACD  12  via the ACD panel  18  to provide power in the event of a power transmission loss from the 120 VAC mains  21  to the ACD  12 . The ACD  12  continuously monitors the ACD battery  22  and maintains a charge of the ACD battery  22  close to full capacity. Typically, the ACD battery  22  can continue operation for a pre-selected period of time such as eight (8) hours. A remaining charge capacity left after eight (8) hours of operation is provided to support the alarm mode operation. Each of the PLNAs  16  includes provisions for an optional PLNA rechargeable backup battery that operates in similar fashion to the ACD battery  22 . A failure of the ACD battery  22  and/or the PLNA battery results in a fault condition of the supplemental alerting system  10 .  
      Referring now to  FIG. 4 , an exemplary hotel room  40  implementing the supplemental alerting system is shown. The hotel room  40  includes a door radio frequency (RF) transmitter  42 , a door  44 , a phone RF transmitter  46 , and the PLNAs  48  and  50 . Each of the PLNAs  48  and  50  are optionally equipped with RF receivers. As depicted, the PLNAs  48  and  50  respectively receive power and communicate with the ACD  12  via the 120 VAC mains  21 . The RF receivers of the PLNAs  48  and  50  receive non-emergency alarm notification signals from various non-emergency alarm transmitters within the hotel room  40 . In the present implementation, PLNAs  48  and  50  respectively communicate with the door RF transmitter  42  and the phone RF transmitter  46  though communication with additional alarm transmitters is contemplated. For example, the door RF transmitter  42  can transmit a door alarm notification signal when a user opens and/or closes a door  44  of hotel room  40 . The phone RF transmitter  46  can transmit a phone alarm notification signal when a phone (not shown) within the hotel room  40  receives a call. The hotel room  40  employs an RF system based on a distinct RF address associated with the channel assigned to the hotel room  40 . It should be noted that the term “non-emergency” as used herein is meant to distinguish from the fire alarm signal. If desired, an RF based emergency alarm signal may also be provided.  
      Referring now to  FIG. 5 , a plurality of hotel rooms is depicted. Hotel rooms  50 - 1 , . . . , and  50 - 4 , referred to collectively as hotel rooms  50 , correspond to RF addresses  52 - 1 , . . . , and  52 - 4 , referred to collectively as RF addresses  52 , respectively. Each of the hotel rooms  50  employ a distinct RF address  52  resulting in each of the hotel rooms  50  operating independently of each other.  
      Referring now to  FIGS. 6A and 6B , a PLNA  60  is shown in more detail. A sealed protective (e.g., plastic) enclosure  62  houses the PLNA  60  to protect the PLNA  60  from environmental conditions (e.g., humidity). Preferably, the PLNA  60  removably attaches to a wall (not shown) of an operating location via an electric outlet (not shown). Optionally, the PLNA  60  can be hard wired to a fixed position within the operating location. Positioning and location of the PLNA  60  conforms with the National Fire Protection Association requirements for a fire alerting device.  
      The PLNA  60  includes a PLNA fire alarm indicator  64  and various other non-emergency PLNA alarm indicators  66  including, but not limited to, door and phone alarm indicators. In the present implementation, the PLNA fire alarm indicator  64  includes a Candela strobe light enclosed in a highly reflective enclosure that provides for constant brightness.  
      The PLNA  60  becomes operational based on receiving power from either the 120 VAC mains  21  or a PLNA backup battery  72 . The PLNA backup battery  72  typically requires a “fast charge” for a period of time (e.g. 3 hours) prior to switching to “trickle charge”. The PLNA  60  establishes communication with the ACD  12  once the ACD  12  becomes operational. The ACD  12  determines and stores the encoded address of the PLNA  60  in a non-volatile memory of the ACD  12 .  
      As discussed in  FIG. 4 , the PLNA  60  can include an optional RF receiver (not shown). The non-emergency PLNA alarm indicators  66  can include door and phone alarm indicators that illuminate based on receiving door and phone alarm signals, respectively. The PLNA  60  can include a program button  68  that instructs the PLNA  60  to determine the addresses of various RF transmitters within a detection proximity or zone based on initializing alarms of the various other alarm transmitters or the activation of the alarm test input  34 . The PLNA  60  responds to RF transmitters that the PLNA  60  has been programmed to accept within a detection zone. For example, various RF transmitters communicating with a single PLNA may be located in adjacent hotel rooms. Programming a PLNA to detect specific RF transmitters allows for increased flexibility of operation of the PLNAs. In the present implementation, turning “ON” the program button  68  illuminates the non-emergency PLNA alarm indicators  66  thereby indicating a program mode of the PLNA  60 . The non-emergency PLNA alarm indicators  66  cease to illuminate when the PLNA  60  accepts the addresses of the various RF transmitters.  
      Additionally, the PLNA  60  includes a dual-color indicator light  70  that indicates the operating mode of the PLNA  60  and a PLNA rechargeable backup battery  72 .  
      Referring now to  FIG. 7 , a method  700  for operating the supplemental alerting system  10  is shown. The method  700  begins in step  702  and continues to step  704 . In step  704 , The ACD  12  determines whether an alarm mode of an associate fire alarm system is detected. If an alarm mode is detected, the method  700  proceeds to step  706 . If no alarm mode is detected, the method  700  proceeds to step  714 . In step  706 , the ACD  12  generates and transmits a fire alarm code signal to each of the PLNAs  16 . In step  708 , each of the PLNAs  16  generates an emergency stimulus.  
      In step  710 , the ACD  12  determines if an alarm mode continues to be detected. If an alarm mode is still detected, the method  700  returns to step  708 . If no alarm mode is detected, the method  700  proceeds to step  712 . In step  712  the fire control panel  14  is reset. After step  712 , the method  700  continues to step  714 . In step  714 , the ACD  12  transmits an acknowledge command to each of the PLNAs  16 . In step  716 , the ACD  12  determines whether a particular PLNA  16  fails to transmit an acknowledgment response to the ACD  12 . If the PLNA  16  fails to respond, the method  700  proceeds to step  718 . If the PLNA  16  responds, the method  700  proceeds to step  724  and ends.  
      In step  718 , the ACD  12  determines whether the number of failures of the failed PLNA exceeds a pre-selected number. If the number of failures of the failed PLNA has not exceeded the pre-selected number, the method  700  returns to step  714 . If the number of failures of the failed PLNA exceeds the pre-selected number, the method  700  proceeds to step  720 . In step  720 , the ACD  12  illuminates an ACD alarm indicator that corresponds to the failed PLNA and/or enables an audible alarm. In step  722 , the ACD  12  determines whether the ACD  12  has established communication with the failed PLNA. If the ACD  12  has not established communication with the failed PLNA, the method  700  returns to step  720 . If the ACD  12  has established communication, the method  700  proceeds to step  724  and ends.  
      The above description is merely exemplary in nature and, thus, variations are intended to be within the scope of the claims. Such variations are not to be regarded as a departure from the spirit and scope of the claims.