ALARM SYSTEM

CROSS-REFERENCE TO RELATED APPLICATION(S)

[001] The present application claims the benefit of priority to Indian Provisional Application No. 201911022183, filed June 4, 2019 and entitled“COMMON DEVICE FOR DRILL AND FIRE ALARM OPERATIONS IN A FIRE ALARM SYSTEM,” the contents of which is incorporated by reference in the entirety.

BACKGROUND

[002] Currently, a manual call point may be provided to initiate a fire alarm on a fire monitoring system, for example, by pulling the call point manually. Drill procedures are designed to teach individuals how a fire alarm system responds to an outbreak of fire. Drill operations can be initiated by using the same manual call point that is used in the event of a real fire. This dual use, however, can cause inefficiencies and/or confusion. Thus, improvements in fire alarm systems are desired.

SUMMARY

[003] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the DETAILED DESCRIPTION. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[004] In an implementation, the present disclosure relates to a fire alarm system. The fire alarm system includes a call station having a fire alarm switch and a drill operation switch, where actuation of the fire alarm switch causes a first fire alarm signal and actuation of the drill operation switch causes a second fire alarm signal different from the first fire alarm signal. The fire alarm system further includes a fire alarm control panel including a memory in communication with a processor. The processor is configured to detect a fire alarm signal, determine whether the fire alarm signal is the first fire alarm signal or the second fire alarm signal, transmit a first notification signal to one or more notification appliances and transmit a second notification signal to a fire department in response to the fire alarm signal being the first fire alarm signal, and transmit the first notification signal to one or more notification appliances and bypass sending the second notification signal to the fire department in response to the fire alarm signal being the second fire alarm signal.

[005] In an aspect, the fire alarm system of this implementation may include a fire threshold and a drill operation threshold in the memory, and wherein to determine whether the fire alarm signal is the first fire alarm signal or the second fire alarm signal the processor is further configured to identify the first fire alarm signal having a first voltage corresponding to the fire threshold, and to identify the second fire alarm signal having a second voltage corresponding to the drill operation threshold.

[006] In another implementation, the present disclosure relates to a method of operating a fire alarm system, comprising: receiving a fire alarm signal from a call station having a fire alarm switch and a drill operation switch; determining whether the fire alarm signal is a first fire alarm signal or a second fire alarm signal different from the first fire alarm signal, wherein the first fire alarm signal corresponds to actuation of the fire alarm switch, and wherein the second fire alarm signal corresponds to actuation of the drill operation switch; transmitting a first notification signal to one or more notification appliances and transmit a second notification signal to a fire department in response to determining that the fire alarm signal is the first fire alarm signal; and transmitting the first notification signal to one or more notification appliances and bypassing the transmitting of the second notification signal to the fire department in response to determining that the fire alarm signal is the second fire alarm signal.

[007] In an aspect of the above method, in order to determine whether the fire alarm signal is the first fire alarm signal or the second fire alarm signal the method may further comprise identifying the fire alarm signal as the first fire alarm signal having a first voltage corresponding to a fire threshold, or identifying the fire alarm signal as the second fire alarm signal having a second voltage corresponding to a drill operation threshold.

[008] In another implementation, the present disclosure may include a computer- readable medium storing instructions executable by a processor to operate a fire alarm system, comprising: receiving a fire alarm signal from a call station having a fire alarm switch and a drill operation switch; determining whether the fire alarm signal is a first fire alarm signal or a second fire alarm signal different from the first fire alarm signal, wherein the first fire alarm signal corresponds to actuation of the fire alarm switch, and wherein the second fire alarm signal corresponds to actuation of the drill operation switch; transmitting a first notification signal to one or more notification appliances and a second notification signal to a fire department in response to the fire alarm signal being the first fire alarm signal; and transmitting the first notification signal to one or more notification appliances and bypassing transmission of the second notification signal to the fire department in response to the fire alarm signal being the second fire alarm signal.

[009] In an aspect of the above computer-readable medium, in order to determine whether the fire alarm signal is the first fire alarm signal or the second fire alarm signal the instructions are executable by the processor to further identify the fire alarm signal as the first fire alarm signal having a first voltage corresponding to a fire threshold, or identify the fire alarm signal as the second fire alarm signal having a second voltage corresponding to a drill operation threshold.

[0010] The device of the present disclosure is described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The features believed to be characteristic of aspects of the disclosure are set forth in the appended claims. In the description that follows, like parts are marked throughout the specification and drawings with the same numerals. The drawing figures are not necessarily drawn to scale and certain figures may be shown in exaggerated or generalized form in the interest of clarity and conciseness. The disclosure itself, however, as well as a preferred mode of use and further advantages thereof, will be best understood by reference to the following detailed description of illustrative aspects of the disclosure when read in conjunction with the accompanying drawings, wherein:

[0012] FIG. 1 is a schematic diagram of an example fire alarm system, including various inputs provided to the fire alarm system as well as corresponding outputs;

[0013] FIG. 2. is a front plan view of an example manual fire alarm call station including a manual fire alarm lever for indicating a fire alarm and a separate switch for indicating a fire drill operation;

[0014] FIG. 3 is a left side perspective view of the manual fire alarm call station of FIG. 2 in a partially opened position, including the internal hardware for both a fire alarm switch for indicating a fire alarm as well as a separate switch for indicating a fire drill operation;

[0015] FIG. 4 is a front perspective view of the manual fire alarm call station of FIG. 2 in a partially opened position, including the internal hardware for both a fire alarm switch for indicating a fire alarm as well as a separate switch for indicating a fire drill operation;

[0016] FIG. 5 is a flowchart of an example method of operation of the fire alarm system of FIG. 1; [0017] FIG. 6 is a block diagram of a more detailed example of the fire alarm system, according to aspects of the present disclosure;

[0018] FIG. 7 is a schematic diagram of an example signal conditioning circuit which may be implemented in the fire alarm control panel of FIG. 6, according to aspects of the present disclosure; and

[0019] FIG. 8 is a block diagram of an example computing device which may implement a component in the example system of FIGS. 1-7, according to aspects of the present disclosure.

DETAILED DESCRIPTION

[0020] Fire drill operations may be initiated by using the same manual fire alarm call point/station that is used in the event of a real fire. Current conventional fire alarm systems are unable to distinguish between whether the manual fire alarm call point/station is pulled for an actual fire alarm or for a drill operation. Therefore, before conducting any fire drills or tests, currently it is often required to disconnect a city circuit module, and if a digital alarm communicator transmitter (DACT) is connected to the fire alarm system, to notify the corresponding monitoring service.

[0021] To addresses one or more of the above issues, the present disclosure relates to a manual fire alarm call station that includes two separate and distinct switches: a fire alarm switch to indicate a fire alarm; and a drill operation switch to indicate a fire drill and hence avoid notifying the fire department in case of a fire drill. In some implementations, the additional switch for drill operations can be inserted into already existing manual fire alarm call stations, e.g., the additional switch may be retrofitted into existing manual fire alarm call stations.

[0022] In one implementation, for example, the additional switch may be a small tact switch with a series resistor, and current detection techniques (such as, but not limited to, general purpose input output (GPIO) / analog to digital converter (ADC) detection) in the hardware may be modified, allowing a fire alarm control panel to differentiate between alarms generated by the fire alarm switch and alarms generated by the drill operation switch. In some aspects, the fire alarm switch may be a contact. As such, in a conventional fire alarm system where a fire alarm control panel monitors changes in voltage to detect actuation of a fire alarm, the fire alarm switch and the drill operation switch may have a different effect on the voltage sensed by the fire alarm control panel, thereby enabling the fire alarm control panel to detect which switch is actuated. [0023] Specifically, in one implementation but not limited thereto, logic for detection of the alarm condition by the fire alarm switch or the drill operation switch may be added in the firmware or software of the fire alarm control panel to identify the source of alarm in the fire alarm system. For example, the fire alarm control panel may compare the detected voltage to known thresholds associated with each of the fire alarm switch and the drill operation switch. As such, when the fire alarm switch is pressed, the fire alarm control panel will activate devices connected to a notification appliance circuit (NAC) as per configuration and will update the alarm status by communicating to the central station via a city circuit or DACT. However, when the drill operation switch is pressed, the fire alarm control panel will perform the drill operations and activate devices connected to a NAC, but will not communicate to the central station via a city circuit or DACT, and hence will avoid erroneously notifying the fire department or other emergency personnel or monitoring services.

[0024] These and other features of the disclosed manual fire alarm call station will be discussed in more detail below with reference to FIGS. 1-8.

[0025] Referring to FIG.1, an example fire alarm system 20 can identify a fire alarm signal from a manual fire alarm call station 24 as indicating a fire or a drill operation and can correspondingly notify or refrain from notifying fire department and/or emergency services and/or other supervising stations. For example, the fire alarm system 20 includes a dual function manual fire alarm call station 24 that includes a lever 50 to actuate a fire alarm switch configured to cause a first fire alarm signal 33, e.g., to indicate a fire 35, and a drill operation switch 52 configured to cause a second fire alarm signal 37, e.g., to indicate a drill operation 39. To avoid unnecessarily alerting authorities during drill operations, the fire alarm system 20 further includes a fire alarm control panel 30 having an alarm determiner component 31 configured to receive a fire alarm signal and distinguish whether the fire alarm signal is the first fire alarm signal 33 indicating the fire 35 or the second fire alarm signal 37 indicating the drill operation 39. Correspondingly, the fire alarm control panel 30 also includes an alarm notification generator component 41 that generates at least a first notification signal 43 and a second notification signal 45 in response to the identification of the first fire alarm signal 33 indicating the fire 35, and which generates the first notification signal 43 but bypassing generating the second notification signal 45 in response to the identification of the second fire alarm signal 37 indicating the drill operation 39. For instance, the first notification signal 43 may activate one or more notification appliances and the second notification signal 45 may alert a fire department.

[0026] Additionally, in one example implementation, the fire alarm system 20 may include various inputs provided by various input devices to the fire alarm control panel 30. In some aspects, the input devices may be connected to one or more input device circuits (IDCs) 31 in the fire alarm control panel 30. For example, the inputs may include, but are not limited to, one or more of each of the following: a smoke detector 22 configured to detect and signal presence of smoke, a manual fire alarm call station 24 configured to generate the first fire alarm signal 33 or the second fire alarm signal 37, a water flow switch 26 configured to send an alarm when a flow of water occurs through piping of a fire sprinkler system from an activated sprinkler head or a leak in the system, and a sprinkler supervisory switch 28 configured to detect unauthorized operation of a main control valve in a sprinkler or standpipe system. Information from these inputs is then transmitted to the fire alarm control panel 30, which includes logic to detect each of the different signals from each of the inputs and generate one or more appropriate response signals to outputs of the fire alarm system 20. The fire alarm system 20 may include other input/output devices, such as but not limited to: a computer/keyboard 32 for providing user inputs or generating outputs to a user, one or more annunciators 34 that indicate a system or zone status, and one or more output devices, such as a printer 36.

[0027] After the fire alarm control panel 30 has processed the inputs, the fire alarm control panel 30 may then transmit one or more notification signals to one or more outputs of the fire alarm system 20 via one or more output interfaces. For example, the output interfaces may include, but are not limited to: a NAC interface 47 connected to one or more notification devices, an auxiliary (AUX) relay 48 connected to one or more auxiliary systems, and a city circuit 49 connected to one or more emergency services. For instance, in one implementation, the NAC interface 47 transmits notification signals to activate audible devices 38 and/or visible devices 40. The AUX relay 48 transmits notification signals to deactivate/close one or more heating, ventilation, and air conditioning (HVAC) system fans/dampers 42, and/or to open or release one or more door locks and hold open devices 44. Also, for example, the city circuit 49 transmits notification signals to notify and dispatch, for instance, the fire department 46.

[0028] In some aspects, the fire alarm control panel 30 may include a 120 V AC power supply 21. In some alternative and/or additional aspects, the fire alarm control panel 30 may include a battery 23. In some aspects, the fire alarm control panel 30 may also include program distribution hardware/software 25 that communicates with various components of the fire alarm control panel 30 to implement the functionalities described herein. In some aspects, the program distribution hardware/software 25 may also communicate with a user interface 27 of the fire alarm control panel 30.

[0029] Referring to FIGS. 2-4, an example manual fire alarm call station 24 includes a manual call point lever 50 (FIG. 2) that may be pressed down in the event of a fire emergency to actuate a fire alarm switch 51 (FIG. 3). The actuation of the fire alarm switch 51 generates the first fire alarm signal 33, which may be detected by the fire alarm control panel 30. Additionally, the drill operation may be initiated by a user pressing the drill operation switch 52 which may be a tact switch. The actuation of the fire alarm switch 51 generates the first fire alarm signal 33, which may be detected by the fire alarm control panel 30.

[0030] In an implementation, the drill operation switch 52 may be recessed within a front face of the manual fire alarm call station 24, and thus may be actuated by using a pointed device such as a screw driver, etc.

[0031] In an implementation, operation of the fire alarm switch 51 and the drill operation switch 52 may generate signals of different characteristics, which can be distinguished from one another and from signals corresponding to normal system operation by the fire alarm control panel 30. For example, the drill operation switch 52 may include a series resistance of 220 ohms. Hence, actuation of the drill operation switch 52 may generate a different threshold voltage level as compared to the fire alarm switch 51, and/or as compared to a signal corresponding to normal system operation. In one implementation, the fire alarm control panel 30 may detect different voltage levels using an analog to digital converter (ADC) interface, and will differentiate between the alarm and drill operations. More specifically, for example, the actuation of the fire alarm switch 51 may generate the first fire alarm signal 33 having a threshold level of 0.7V at the ADC, and the actuation of the drill operation switch 52 may generate the second fire alarm signal 37 having a threshold level of 2.0V at the ADC. During normal operation, the fire alarm control panel 30 may receive a signal having a normal threshold level of 207V at the ADC.

[0032] Referring to FIGS. 3 and 4, the example manual fire alarm call station 24 may have the fire alarm switch 51 extending from a back mounting plate and positioned to be actuated by movement of the manual call point lever 50 (FIG. 2). The drill operation switch 52 may be relatively smaller in size, and may extend less toward a front face of the manual fire alarm call station 24.

[0033] Referring to FIG. 5, an example method 60 of operation of the fire alarm system 20 includes configuring a call station with the fire alarm switch 51 and the drill operation switch 52 at block 62. The remainder of the method 60 may be operated by the fire alarm control panel 30, such as via a processor and a memory configured to execute the alarm determiner component 31 and the alarm notification generator component 41 as described herein.

[0034] At block 64, the method 60 includes reading a status of a zone based on a signal. For example, in an aspect, this includes reading the signal at the ADC interface.

[0035] At block 66, a determination is made as to whether the signal corresponds to a normal operation threshold. For example, in an aspect, this includes if the ADC counts correspond to normal threshold counts.

[0036] If no, then the method 60 returns to block 64.

[0037] If yes, then the method 60 proceeds to block 68, and a determination is made as to whether the signal corresponds to a fire alarm threshold. For example, in an aspect, this includes if the ADC counts correspond to fire alarm threshold counts.

[0038] If the signal is determined to be a fire alarm at block 68, then the method 60 proceeds to block 70 and will initiate notification devices via NAC interface 47 (see FIG. 1) as per configuration, and at block 72 will update the alarm status via the city circuit 49 (see FIG. 1) as well as on the DACT at block 74.

[0039] Alternatively, if the signal is not a fire alarm at block 68, the method 60 proceeds to block 76 to determine whether the signal corresponds to a drill operation. For example, in an aspect, this includes if the ADC counts correspond to drill operation threshold counts.

[0040] If the drill operation is detected, then the method 60 proceeds to block 78 and will initiate notification devices via NAC interface 47 (see FIG. 1) as per configuration but will not update the alarm status via the city circuit 49 (see FIG. 1) nor the DACT.

[0041] After going through the fire alarm operations or the drill operations, the method

60 proceeds to block 80, where a determination is made as to whether the fire alarm panel has been reset. If not, then the method 60 returns to performing the fire alarm operations or the drill operations. If so, then the method 60 proceeds to block 82 and stops all NAC devices, resets all IDC zones, and resets all other aspects of the system.

[0042] After block 82, the method 60 proceeds back to block 64. [0043] Referring to FIG. 6, in a more detailed example implementation, the fire alarm system 20 includes the fire alarm control panel 30 coupled with an input loop 122 of a fire protection zone. The input loop 122 is terminated at one end at a pair of connection points at the fire alarm control panel 30, including: a regulated zone power connection 124 that provides electrical power to the input loop 122, and a feedback line connection 126 that, after undergoing signal conditioning by signal conditioning circuit 130, interfaces an ADC 129 of a controller 112 of the fire alarm control panel 30.

[0044] The input loop 122 is also terminated at an opposite end with an end of line resistor (EOLR) 128, which may be, for example, a 3.3 kOhms resistor. The input loop 122 connects the fire alarm control panel 30 to the manual fire alarm call station 24 having the fire alarm switch 51 and the drill operation switch 52. The fire alarm switch 51 is a contact switch, while the drill operation switch 52 includes a resistor 110 (e.g., a 220 Ohms resistor) configured in series. As such, the effective resistance of the input loop 122 and hence the electrical voltage of the input loop 122 observable at the controller 112 may be indicative of the status of a normal operation of the system, or an actuation of either of the fire alarm switch 51 and the drill operation switch 52. Accordingly, the controller 112 may monitor the electrical voltage at the feedback line connection 126 to determine if the fire 35 or the drill operation 39 is detected, and may provide corresponding indications on a user interface 27 of the fire alarm control panel 30 and/or activate one or more notification devices 106 (e.g., see FIG. 1 : audible devices 38, visible devices 40, etc.), or emergency control devices 108 (e.g., see FIG. 1 : HVAC system fans/dampers 42, door locks and hold open devices 44, etc.), or the fire department 46 or other monitoring services.

[0045] More specifically, for example, in an aspect, the fire alarm control panel 30 may be configured to respond to a change in the electrical voltage at the feedback line connection 126. Under normal conditions where neither the fire alarm switch 51 nor the drill operation switch 52 are activated along the input loop 122, a standard or normal amount of current flows through the input loop 122 and the value of the electrical voltage at the feedback line connection 126 is affected at least partially by the resistor 110 and the EOLR 128. However, when either the fire alarm switch 51 or the drill operation switch 52 are actuated, the electrical contacts of the switches transition from open circuit to closed/short circuit, which causes a change in the electrical voltage at the feedback line connection 126. The fire alarm control panel 30 may then sense such a change and in response transition into an alarm state corresponding to if the fire 35 or the drill operation 39.

[0046] Referring to FIG. 7, an example of the signal conditioning circuit 130 conditions the electrical voltage at the feedback line connection 126 and couples the feedback line connection 126 with an ADC input of the controller 112. In an aspect, for example, the controller 112 may be an NXP LPC4078FBD144 MCU microcontroller that includes a 12 bit resolution ADC. In an aspect, for example, the signal conditioning circuit 130 may include operation amplifier (op-amp) circuits that implement a comparator and a buffer for interfacing the ADC input of the controller 112.

[0047] Referring to FIG. 8, a computing device 200 may implement all or a portion of the functionality described in FIGS. 1-7 above. For example, the computing device 200 may be or may include at least a portion of the fire alarm control panel 30, the controller

112, or any other component described herein with reference to FIGS. 1-7 above. The computing device 200 includes a processor 202 which may be configured to execute or implement software, hardware, and/or firmware modules that perform some or all of the functionality described herein with reference to FIGS. 1-7. For example, the processor

202 may be configured to execute or implement software, hardware, and/or firmware modules that perform some or all of the functionality described herein with reference to fire alarm system 20, the fire alarm control panel 30, the controller 112, the user interface

27, or any other component/system/device described herein with reference to FIGS. 1-7.

[0048] The processor 202 may be a micro-controller, an application-specific integrated circuit (ASIC), or a field-programmable gate array (FPGA), and/or may include a single or multiple set of processors or multi-core processors. Moreover, the processor 202 may be implemented as an integrated processing system and/or a distributed processing system. The computing device 200 may further include a memory 204, such as for storing local versions of applications being executed by the processor 202, related instructions, parameters, etc. The memory 204 may include a type of memory usable by a computer, such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof.

Additionally, the processor 202 and the memory 204 may include and execute an operating system executing on the processor 202, one or more applications, display drivers, etc., and/or other components of the computing device 200.

[0049] Further, the computing device 200 may include a communications component 206 that provides for establishing and maintaining communications with one or more other devices, parties, entities, etc. utilizing hardware, software, and services. The communications component 206 may carry communications between components on the computing device 200, as well as between the computing device 200 and external devices, such as devices located across a communications network and/or devices serially or locally connected to the computing device 200. In an aspect, for example, the communications component 206 may include one or more buses, and may further include transmit chain components and receive chain components associated with a wireless or wired transmitter and receiver, respectively, operable for interfacing with external devices.

[0050] Additionally, the computing device 200 may include a data store 208, which can be any suitable combination of hardware and/or software, that provides for mass storage of information, databases, and programs. For example, the data store 208 may be or may include a data repository for applications and/or related parameters not currently being executed by processor 202. In addition, the data store 208 may be a data repository for an operating system, application, display driver, etc., executing on the processor 202, and/or one or more other components of the computing device 200.

[0051] The computing device 200 may also include a user interface component 210 operable to receive inputs from a user of the computing device 200 and further operable to generate outputs for presentation to the user (e.g., via a display interface to a display device). The user interface component 210 may include one or more input devices, including but not limited to a keyboard, a number pad, a mouse, a touch-sensitive display, a navigation key, a function key, a microphone, a voice recognition component, or any other mechanism capable of receiving an input from a user, or any combination thereof. Further, the user interface component 210 may include one or more output devices, including but not limited to a display interface, a speaker, a haptic feedback mechanism, a printer, any other mechanism capable of presenting an output to a user, or any combination thereof.

[0052] It will be appreciated that various implementations of the above-disclosed and other features and functions, or alternatives or varieties thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.