Patent Description:
Patent Literature <NUM> discloses an exemplary known fire alarm device. The fire alarm device includes: a fire detection unit for determining whether or not either a temperature or a smoke concentration is greater than a fire threshold value and deciding, when finding the temperature or smoke concentration greater than the fire threshold value, that a fire should be present, thereby detecting the presence of the fire; and an alarm unit for lighting, when detecting the presence of the fire, an indicating lamp as a fire warning and emitting an alarm sound as an alert to the presence of the fire. The fire alarm device further includes a replacement detection unit for detecting that a replacement timing has come; and an alert unit for calling a replacement alert when detecting that the replacement timing has come.

<CIT> discloses: An intelligent thermostat communicates with battery-powered threat detectors, such as smoke detectors, to allow remote quieting and coordination of a low battery warning detected by the threat detector. In one embodiment, the threat detector transmits a pre-warning signal to the thermostat indicating that a low battery condition is imminent. The thermostat uses this information to display a pre-warning to the consumer so that the consumer may better coordinate replacing of the battery at a convenient time. Once a low battery condition has been detected, the threat detector transmits a low battery warning signal to the thermostat. The thermostat then displays a warning message and an option for the consumer to quiet the chirping for a period of time from the thermostat. Preferably, the thermostat automatically quiets the chirping during quite times so as to not disturb the consumer.

Regarding an internal event (such as the replacement timing) that may occur to the fire alarm device (device) itself, even if the user is notified of the internal event after the internal event has happened, it could be too late to notify the user of such an event. Nevertheless, if the fire alarm device (device) itself calls the replacement alert simply at an earlier time, then such an unnecessarily early replacement alert could make the user uncomfortable and could possibly impair the usefulness of the fire alarm device.

In view of the foregoing background, it is therefore an object of the present disclosure to provide a control system, a device management system, a control method, and a program, all of which are configured or designed to provide the user with device status information at an earlier time while reducing the chances of impairing the usefulness of the device.

The present invention relates to device management system according to independent claim <NUM>, to a control method according to independent claim <NUM>, and to a program according to independent claim <NUM>. Some of the preferred embodiments are described in the dependent claims, in the description and in the figures.

Note that the drawings to be referred to in the following description of embodiments are all schematic representations. That is to say, the ratio of the dimensions (including thicknesses) of respective constituent elements illustrated on the drawings does not always reflect their actual dimensional ratio.

A control system <NUM> according to this embodiment is connected to a device <NUM> to be ready to communicate with the device <NUM>. Also, a device management system <NUM> according to this embodiment includes the control system <NUM> and a plurality of devices <NUM> as shown in <FIG>.

Each device <NUM> is supposed to detect a particular event, for example. In other words, each device <NUM> includes a detection unit <NUM> for outputting a detection signal to be generated as a signal indicative of the particular event.

As used herein, the "particular event" is an event that calls for disaster prevention measures. That is to say, the device <NUM> is supposed to be a disaster prevention device. Also, the "event that calls for disaster prevention measures" is herein supposed to be a fire. That is to say, the device <NUM> is supposed to be a fire detector. In particular, the device <NUM> is supposed to be a fire alarm device having a detection capability of detecting the presence of a fire and an alarm capability of calling an alert when detecting the presence of a fire. In the following example, the detector <NUM> is supposed to be a "residential" fire alarm device. However, this is only an example of the present disclosure and should not be construed as limiting. The device <NUM> emits a sound such as an alarm sound when detecting the presence of a fire, for example. Nevertheless, the event that calls for disaster prevention measures does not have to be a fire but may also be an inundation or an earthquake, for example. Alternatively, the event that calls for disaster prevention measures may also be leakage of a gas or the presence of carbon monoxide (CO) due to incomplete combustion, for example. Furthermore, the "particular event" does not have to include the event that calls for disaster prevention measures.

As used herein, the "particular event" is supposed to include not only an event that calls for disaster prevention measures but also an internal event that is going to happen to the device <NUM> itself.

As used herein, the "internal event" refers to an event, of which the degree advances with the passage of time, for example. The "internal event" includes at least one of a timing to replace the device <NUM> (replacement timing), a malfunction of the device <NUM> (such as a malfunction of a circuit component thereof and disconnection), a low battery level (i.e., a state where its battery <NUM> is on the verge of running out), the dirtiness of the device <NUM>, or an abnormal temperature inside the device <NUM>. In the following description, the internal event is supposed to include a replacement timing, a malfunction, a low battery level, and dirtiness.

The detection unit <NUM> includes, at least one of a first detection unit <NUM> for detecting a fire, a second detection unit <NUM> for detecting a replacement timing, a third detection unit <NUM> for detecting a malfunction of the device <NUM>, a fourth detection unit <NUM> for detecting a low battery level, and a fifth detection unit <NUM> for detecting the degree of dirtiness (see <FIG>).

The device management system <NUM> is applicable for use in a facility <NUM> (see <FIG>). Specifically, a plurality of devices <NUM> are installed on the ceiling, wall, or any other building component located in their installation space inside the facility <NUM>. In this embodiment, the plurality of devices <NUM> are respectively installed (at their respective installation locations L1) in spaces E1-E5 inside the facility <NUM> as shown in <FIG>.

The control system <NUM> may be, for example, a single controller <NUM> housed in a single housing and may be a home energy management system (HEMS) controller installed in the facility <NUM>, for example. However, the control system <NUM> does not have to be such a controller <NUM> housed in the single housing but may also include a plurality of controllers in which multiple functions are distributed or may further include an external server device.

As described above, the device <NUM> may be implemented as a fire alarm device, for example, and the facility <NUM> is supposed to be a single-family dwelling house, for example. However, this is only an example of the present disclosure and should not be construed as limiting. The facility <NUM> may also be a multi-family dwelling house (condominium) (i.e., what is called a "mansion" in Japan). Alternatively, the facility <NUM> may also be a non-residential facility <NUM>. Examples of such non-residential facilities include office buildings, theaters, movie theaters, public halls, amusement facilities, complex facilities, restaurants, department stores, schools, hotels, inns, hospitals, nursing homes for the elderly, kindergartens, libraries, museums, art museums, underground shopping malls, railway stations, and airports.

The control system <NUM> (controller <NUM>) includes an acquisition unit <NUM> and an output unit <NUM>. The acquisition unit <NUM> acquires, from the device <NUM>, device information about an internal event that is going to happen to the device <NUM> itself. The output unit <NUM> outputs early signs information about any early signs of an internal event. The early signs information is based on the device information.

According to this configuration, the control system <NUM> outputs early signs information about any early signs of an internal event that is going to happen to a device <NUM> itself. This allows a destination device, for example, to learn about the early signs of the internal event via the control system <NUM>. This enables the user to be provided with information about the device's <NUM> status at an earlier time while reducing the chances of impairing the usefulness of the device <NUM>.

Next, an overall configuration for the controller <NUM> (control system <NUM>) and device management system <NUM> according to this embodiment will be described in detail.

As shown in <FIG>, the device management system <NUM> includes the controller <NUM> and a plurality of (e.g., five in the example illustrated in <FIG>) devices <NUM>. Optionally, the device management system <NUM> may further include a telecommunications device <NUM> and an external server <NUM> (see <FIG>).

The plurality of devices <NUM> are implemented as so-called "synchronous fire alarm devices. " That is to say, the device management system <NUM> is configured such that no matter which of the plurality of devices <NUM> detects the presence of a fire, the device <NUM> emits an alarm sound in synch with (i.e., along with) the other devices <NUM>. In this embodiment, a network is formed between the plurality of devices <NUM> to make each device <NUM> ready to communicate with the other devices <NUM>. In this embodiment, out of the five devices <NUM>, a device 1A serves as a master device, the other devices 1B-1E serve as slave devices, and communication may be readily established between the master device and the slave devices (see <FIG>). In the following description, the four devices 1B-1E serving as slave devices will be hereinafter collectively referred to as "slave devices <NUM>" and the device 1A serving as a master device will be hereinafter referred to as a "master device <NUM>".

In this embodiment, the device <NUM> may be implemented as a battery-driven fire alarm device, for example. However, this is only an example of the present disclosure and should not be construed as limiting. Alternatively, the device <NUM> may also be electrically connected to an external power supply (such as a commercial power supply) and may be driven by converting AC power (having an effective value of <NUM> V, for example) supplied from the external power supply into DC power.

In the following description, each of the plurality of devices <NUM> is supposed to be installed on the ceiling surface of one of the rooms or the staircase inside the facility <NUM> (e.g., single-family dwelling house in this example) as shown in <FIG>. Specifically, the devices 1A, 1B, 1C, 1D, and 1E are arranged in spaces E1, E2, E3, E4, and E5, respectively. The space E1 may be a living room, for example. The space E2 may be a bedroom, for example. The space E3 may be a staircase, for example. The space E4 may be a kid's room, for example. The space E5 may be a kitchen, for example. <FIG> illustrates an exemplary situation where a fire is present in the space E1 used as a living room. The respective devices <NUM> will be described in detail later in the "(<NUM>) Device" section.

The controller <NUM> is configured to manage the plurality of devices <NUM>. The controller <NUM> is connected to the plurality of devices <NUM> to be ready to communicate with the plurality of devices <NUM> by wireless communication, for example. In the example illustrated in <FIG>, the controller <NUM> is installed beside the flight of stairs on the first floor in the space E3. The controller <NUM>, the telecommunications device <NUM>, and the external server <NUM> will be described in detail later in the "(<NUM>) Controller" section.

Next, configuration(s) for the devices <NUM> will be described. If one device <NUM>, serving as a master device <NUM>, out of the plurality of devices <NUM> has a different configuration from the other devices <NUM> serving as slave devices <NUM>, then the master device <NUM> and the slave devices <NUM> will be described separately from each other.

The device <NUM> is configured to detect the presence of an event (e.g., a fire in this example) that calls for disaster prevention measures. The device <NUM> has a detection capability of detecting the presence of a fire in the facility <NUM> and an alarm capability of calling an alert when detecting the presence of the fire in the facility <NUM>. As shown in <FIG>, the device <NUM> includes a control unit <NUM>, a storage unit <NUM>, a first communications unit <NUM>, a second communications unit <NUM>, a battery <NUM>, a detection unit <NUM>, and an alert unit <NUM>. In addition, the device <NUM> further includes circuit modules such as an audio circuit and a lighting circuit. The battery <NUM> may be a lithium battery, for example, and the device <NUM> is driven by the power supplied from the battery <NUM>.

The control unit <NUM> includes a computer system including a processor and a memory, for example. The computer system performs the function of the control unit <NUM> by making the processor execute a program stored in the memory. In this embodiment, the program to be executed by the processor is stored in advance in the memory of the computer system. However, this is only an example and should not be construed as limiting. The program may also be distributed after having been stored in a storage medium such as a memory card or downloaded via a telecommunications line such as the Internet.

The detection unit <NUM> includes the first detection unit <NUM>, the second detection unit <NUM>, the third detection unit <NUM>, the fourth detection unit <NUM>, and the fifth detection unit <NUM> as described above (see <FIG>).

The first detection unit <NUM> has the capability of detecting information about a fire, against which an alarm sound needs to be emitted (i.e., has the detection capability). In this embodiment, the first detection unit <NUM> may be implemented as a photoelectric sensor for detecting smoke, for example. Therefore, the information about the fire includes information about smoke, for example. However, this is only an example of the present disclosure and should not be construed as limiting. Alternatively, the first detection unit <NUM> does not have to be a photoelectric sensor but may also be a fixed temperature sensor for detecting heat, for example. As shown in <FIG>, the first detection unit <NUM> includes a light-emitting unit <NUM> such as a light-emitting diode (LED) and a photodetector unit <NUM> such as a photodiode, for example. The light-emitting unit <NUM> and the photodetector unit <NUM> are arranged in the labyrinth of the housing of its own device such that the photosensitive plane of the photodetector unit <NUM> is off the optical axis of the light emitted from the light-emitting unit <NUM>. In the presence of a fire, smoke may flow into the labyrinth through holes provided through the housing.

If there is no smoke in the labyrinth of the housing, then the light emitted from the light-emitting unit <NUM> hardly reaches the photosensitive plane of the photodetector unit <NUM>. On the other hand, if there is any smoke in the labyrinth of the housing, then the light emitted from the light-emitting unit <NUM> is scattered by the smoke, thus causing some of the scattered light to impinge on the photosensitive plane of the photodetector unit <NUM>. That is to say, the first detection unit <NUM> makes the photodetector unit <NUM> receive the light emitted from the light-emitting unit <NUM> which has been scattered by the smoke. The first detection unit <NUM> outputs an electrical signal (first detection signal), representing a voltage level corresponding to the quantity of light received at the photodetector unit <NUM>, to the control unit <NUM>. Alternatively, the first detection unit <NUM> may convert the quantity of light into a smoke concentration and output a first detection signal representing a voltage level corresponding to the smoke concentration.

The second detection unit <NUM> is configured to detect a replacement timing of the device <NUM>. If the device <NUM> is a fire alarm device, a decision is made that when about ten years has passed since the installation of the device <NUM> (since when the device <NUM> was powered for the first time), it should be about time to replace the device <NUM> (i.e., the replacement timing should have come). When ten years has passed since its installation, the device <NUM> could no longer be able to sense a fire or call an alert to the fire due to the life of its internal circuit components and a low battery level, for example. That is why it is recommended that the device <NUM> should be replaced when generally ten years has passed since its installation (i.e., with ten years regarded as a reference replacement timing). The second detection unit <NUM> includes a timer, for example, and measures, by using the timer, the cumulative time for which the device <NUM> has been used since the device <NUM> was powered for the first time, for example. The second detection unit <NUM> outputs an electrical signal (as a second detection signal), representing the cumulative time of use, to the control unit <NUM>.

The third detection unit <NUM> is configured to detect a malfunction of the device <NUM>. Examples of malfunctions include a malfunction of a circuit component and disconnection. The third detection unit <NUM> monitors a voltage value or current value (as an electrical physical quantity) of a predetermined electric circuit in various circuits as the target of detection or the temperatures of its circuit components, for example. The third detection unit <NUM> may include a resistance divider circuit and other suitable circuits. The third detection unit <NUM> may also include a heat detection element such as a thermistor. The third detection unit <NUM> outputs an electrical signal (as a third detection signal), representing the voltage value, the current value, or the temperature, for example, to the control unit <NUM>.

The fourth detection unit <NUM> is configured to detect a low battery level of the battery <NUM>. The fourth detection unit <NUM> monitors the battery voltage of the battery <NUM>. The fourth detection unit <NUM> outputs an electrical signal (as a fourth detection signal), representing the battery voltage of the battery <NUM>, to the control unit <NUM>. Optionally, the fourth detection unit <NUM> may store in advance, in a memory, characteristic data showing the correspondence between the battery voltage of the battery <NUM> and capacity and may output, as the fourth detection signal, a capacity (in percent) corresponding to the battery voltage detected.

The fifth detection unit <NUM> is configured to detect the degree of dirtiness. As used herein, the "dirtiness" refers to the dirtiness of the first detection unit <NUM>. Specifically, the dirtiness refers to the dirtiness that could affect the smoke detection performance of the first detection unit <NUM>. Examples of the dirtiness include dirt, dust, oil, and insects that may adhere to the lens surface of the light-emitting unit <NUM> and photodetector unit <NUM> or be deposited in the labyrinth. Particularly if the device <NUM> is installed in a kitchen (space E5), then the degree of dirtiness will advance more quickly due to oil or smoke involved with cooking, for example, than in a situation where the device <NUM> is installed in any other space. As the degree of dirtiness advances, the voltage level, corresponding to the quantity of light received at the photodetector unit <NUM>, is more and more likely to rise from the voltage level at the time of shipping of the device <NUM> to the point of causing the device <NUM> to be activated erroneously, even though smoke involved with a fire has not actually entered the labyrinth. In other words, the advancement of the degree of dirtiness could make the device <NUM> too sensitive to avoid being erroneously activated frequently. The fifth detection unit <NUM> outputs an electrical signal (as a fifth detection signal), representing the concentration of smoke in the labyrinth (or the quantity of light received at the photodetector unit <NUM>), to the control unit <NUM>. The smoke concentration may be obtained based on the quantity of light represented by the first detection signal provided by the first detection unit <NUM>, for example. In other words, the fifth detection unit <NUM> may be covered by the first detection unit <NUM>.

As can be seen, the detection units <NUM> (<NUM>-<NUM>) output first to fifth detection signals, generated as signals indicative of their respective particular events (namely, fire, replacement timing, malfunction, low battery level, and dirtiness), to the control unit <NUM>.

The alert unit <NUM> includes a display unit <NUM> and an audio unit <NUM> as shown in <FIG>. The alert unit <NUM> has the capability of alerting, when the presence of a fire is detected in the facility <NUM>, the user to the presence of the fire (i.e., an alert capability). In this embodiment, the alert unit <NUM> alerts the user with light and sound.

The audio unit <NUM> has the capability of alerting the user to the presence of a fire. The audio unit <NUM> emits a sound (i.e., an acoustic wave). When the control unit <NUM> decides that a fire should be present in the facility <NUM>, the audio unit <NUM> emits an alarm sound to alert the user to the presence of the fire.

The audio unit <NUM> may be implemented as a loudspeaker that transduces an electrical signal into a sound. The loudspeaker includes a diaphragm and emits an alarm sound by mechanically vibrating the diaphragm in accordance with the electrical signal. The audio unit <NUM> emits an alarm sound (such as a beep) under the control of the control unit <NUM>. The audio unit <NUM> suitably emits an alarm sound, of which the loudness (i.e., the sound pressure level) is variable. For example, the alarm sound may include a sweep sound that is swept from a low-frequency sound to a high-frequency sound. The alarm sound may be accompanied by, for example, a verbal warning message such as "Fire! Fire!" In this embodiment, the alarm sound is supposed to be made up of the sweep sound and the verbal warning message continuous with the sweep sound. If the device <NUM> itself triggers the synchronized alarm emission (i.e., serves as a triggering device (located at the origin of the fire)), then the device <NUM> may emit the verbal warning message such as "Fire! Fire!" On the other hand, if the device <NUM> is notified of the presence of the fire (i.e., serves as one of the triggered devices that are caused to emit the alarm sound in synch with the triggering device), then the device <NUM> may emit a verbal warning message such as "Fire in another room! Fire in another room!".

When the device <NUM> receives an operating command externally at an operating member such as a press button or pull cord exposed on the surface of the housing of the device <NUM> (i.e., when subjected to a press operation or a pull operation) while the alarm sound is being emitted, the audio unit <NUM> stops emitting the alarm sound.

Also, when the control unit <NUM> decides that any of the internal events (including the replacement timing, the malfunction, the low battery level, and the dirtiness) should be happening, the audio unit <NUM> emits a sound alerting the user to the internal event happening. Such a sound will be hereinafter referred to as an "alert sound" to be distinguished from the alarm sound emitted in the presence of a fire. The alert sound about the replacement timing of the device <NUM> may be accompanied by a verbal warning message "It's about time to replace it," for example. The alert sound about the malfunction may be accompanied by a verbal warning message "Out of order," for example. The alert sound about the low battery level may be accompanied by a verbal warning message "Battery is running out. " The alert sound about the dirtiness may be accompanied by a verbal warning message "Clean it," for example. The alert sound is emitted at a volume approximately <NUM>-<NUM>% the volume of the alarm sound.

The audio unit <NUM> also emits the alarm sound and the alert sound as a test while an operation test is being conducted. The operation test may be carried out when the device <NUM> is subjected to either a press operation on the operating member or a pull operation on a pull cord.

The display unit <NUM> has the capability of alerting the user to the presence of the fire. The display unit <NUM> may be implemented as an indicating lamp including a red LED <NUM> as a light source. The display unit <NUM> is OFF normally (i.e., while monitoring for any fire) and starts flashing (or lighting) when the control unit <NUM> decides that a fire should be present. When the alarm sound stops being emitted, flashing is stopped under the control of the control unit <NUM>.

The storage unit <NUM> is implemented as a device selected from the group consisting of a read-only memory (ROM), a random-access memory (RAM), an electrically erasable programmable read-only memory (EEPROM), and other storage devices. The storage unit <NUM> stores a unique identifier (identification information) assigned to itself (its own device). The "identifier (identification information)" may be the IP address, the Mac address, or the name of the device <NUM>, for example. In addition, the storage unit <NUM> also stores message data about the verbal warning messages to be emitted as a part of the alarm sound and a part of the alert sound. Optionally, the storage unit <NUM> may be a memory of the control unit <NUM>.

The first communications unit <NUM> includes a communications interface for communicating wirelessly with the other devices <NUM> by using a radio wave falling within a first frequency band. The first frequency band may correspond to a radio frequency band in accordance with the regulations of the Fire Service Act in the country of Japan, for example. The first frequency band may correspond, for example, to the wireless station of the low-power security system, namely, the <NUM> band. However, the first frequency band does not have to be the <NUM> band but may also be changed as appropriate in accordance with applicable regulations of the Radio Act or Fire Service Act defined in any of various other countries. The detection information may be transmitted and received between the plurality of devices <NUM> via the first communications unit <NUM>. As used herein, the "detection information" refers to notification information that a fire has been detected in the facility <NUM> and may include, for example, the identifier of the source device and a result of detection. The device information may also be transmitted and received between the plurality of devices <NUM> via the first communications unit <NUM>. The device information is information about the second to fifth detection signals.

The second communications unit <NUM> includes a communications interface for communicating wirelessly with the controller <NUM> by using a radio wave falling within a second frequency band, which is different from the first frequency band. The second frequency band may be, for example, the <NUM> band compliant with the Wi-SUN® standard (which is an international wireless communication standard IEEE <NUM>. However, the second frequency band does not have to be the <NUM> band but may also be changed as appropriate in accordance with applicable regulations of the Radio Act or Fire Service Act defined in any of various other countries. Out of the plurality of devices <NUM>, the master device <NUM> includes the second communications unit <NUM>. The second communications unit <NUM> is not an essential constituent element for, and may be omitted from, the slave devices <NUM>. Alternatively, if each of a plurality of devices <NUM> having the same configuration is able to operate either as the slave device <NUM> or the master device <NUM> by turning a switch, for example, then the device <NUM> switched to operate as a slave device <NUM> may have its capability as the second communications unit <NUM> disabled, even though the device <NUM> has that capability. The second communications unit <NUM> transmits either the detection information of its own device or the detection information provided by another device to the controller <NUM>. In addition, the second communications unit <NUM> transmits the device information of its own device and the device information provided by another device to the controller <NUM>.

The control unit <NUM> determines, based on the first detection signal provided by the first detection unit <NUM>, whether or not a fire is present. For example, when finding the voltage level of the first detection signal equal to or greater than a predetermined threshold value, the control unit <NUM> may decide that a fire should be present.

When its own device detects the presence of a fire or when its own device receives detection information from another device, the control unit <NUM> makes the audio unit <NUM> start emitting an alarm sound. For example, to make the audio unit <NUM> deliver a verbal warning message as the alarm sound, the control unit <NUM> generates, based on message data stored in the storage unit <NUM>, an audio signal representing the verbal warning message. Then, the audio unit <NUM> delivers the verbal warning message (as a part of an alarm sound) based on the audio signal generated by the control unit <NUM>. Furthermore, the control unit <NUM> further controls the display unit <NUM> to make the display unit <NUM> emit flashing light.

When a slave device <NUM> detects the presence of a fire, the control unit <NUM> of the slave device <NUM> makes the first communications unit <NUM> transmit detection information to the master device <NUM> to serve as a triggering device that triggers the synchronized alarm emission. On the other hand, when receiving the detection information from the slave device <NUM> (serving as the triggering device) via the first communications unit <NUM>, the control unit <NUM> of the master device <NUM> makes the second communications unit <NUM> transmit the detection information provided by the triggering device to the controller <NUM>. In addition, to trigger the synchronized alarm emission, the control unit <NUM> of the master device <NUM> further makes the first communications unit <NUM> transmit an instruction to emit an alarm to the other slave devices <NUM>.

Meanwhile, when the master device <NUM> detects the presence of a fire by itself, the control unit <NUM> of the master device <NUM> makes the second communications unit <NUM> transmit the detection information to the controller <NUM> and also makes the first communications unit <NUM> to transmit an instruction to emit an alarm to the slave devices <NUM> to serve as a triggering device that triggers the synchronized alarm emission.

The control unit <NUM> of each device <NUM> also determines whether or not a fire is present even while emitting the alarm sound. When finding the voltage level represented by the first detection signal less than the threshold value (i.e., when deciding that there should be no fire (smoke) any longer) while the alarm sound is being emitted, the control unit <NUM> instructs the audio unit <NUM> to stop emitting the alarm sound and also instructs the display unit <NUM> to stop emitting the flashing light.

In addition, the control unit <NUM> of each device <NUM> also monitors the second detection signal provided by the second detection unit <NUM>. The control unit <NUM> determines, based on the second detection signal, whether or not the cumulative time of use of its own device has exceeded ten years. On deciding that the cumulative time of use has reached ten years, the control unit <NUM> may make the display unit <NUM> emit flashing light as an alert or may make the audio unit <NUM> emit a verbal warning message "It's about time to replace it," for example.

Furthermore, the control unit <NUM> of each device <NUM> also monitors the third detection signal provided by the third detection unit <NUM>. The control unit <NUM> determines, based on the third detection signal, whether or not any malfunction has occurred to its own device. Specifically, when finding the voltage value (or current value) represented by the third detection signal less than a reference value, for example, the control unit <NUM> decides that a malfunction should have occurred to its own device. Depending on the electric circuit as the target of detection, the control unit <NUM> may decide, when finding the voltage value (or current value) represented by the third detection signal greater than the reference value, that a malfunction should have occurred to its own device. Alternatively, when finding the temperature represented by the third detection signal greater than a reference value, the control unit <NUM> may decide that a malfunction should have occurred to its own device. In any case, when deciding that a malfunction should have occurred to its own device, the control unit <NUM> may make the display unit <NUM> emit flashing light as an alert or may make the audio unit <NUM> emit an alert sound accompanied by a verbal warning message "Gone out of order," for example.

Furthermore, the control unit <NUM> of each device <NUM> also monitors the fourth detection signal provided by the fourth detection unit <NUM>. The control unit <NUM> determines, based on the fourth detection signal, whether or not the battery has run out. Specifically, when finding the battery level represented by the fourth detection signal and corresponding to the battery voltage of the battery <NUM> less than <NUM>% of the capacity, the control unit <NUM> decides that the battery should have run out. When deciding that the battery of its own device should have run out, the control unit <NUM> may make the display unit <NUM> emit flashing light as an alert or may make the audio unit <NUM> emit an alert sound accompanied by a verbal warning message "Battery has run out," for example.

Furthermore, the control unit <NUM> of each device <NUM> also monitors the fifth detection signal provided by the fifth detection unit <NUM>. The control unit <NUM> determines, based on the fifth detection signal, whether or not the degree of dirtiness has reached a significant degree. Specifically, when finding the minimum value of the smoke concentration represented by the fifth detection signal during a predetermined period (of one month, for example) equal to or greater than a first threshold value and less than a second threshold value, the control unit <NUM> decides that the degree of dirtiness has reached a significant degree. The first threshold value is less than the second threshold value. The second threshold value corresponds to a threshold value, at or over which a decision is made that a fire should be present. When deciding that the degree of dirtiness should have reached a significant degree, the control unit <NUM> may make the display unit <NUM> emit flashing light as an alert or may make the audio unit <NUM> emit an alert sound accompanied by a verbal warning message "Clean it," for example. Note that the fifth detection unit <NUM> is not an essential constituent element. Alternatively, the control unit <NUM> may determine, based on the first detection signal provided by the first detection unit <NUM>, whether or not the degree of dirtiness has reached a significant degree.

The control unit <NUM> of each slave device <NUM> makes the first communications unit <NUM> transmit the device information of its own device, in association with the identifier of its own device, to the master device <NUM>. Meanwhile, the control unit <NUM> of the master device <NUM> makes the second communications unit <NUM> transmit the device information and identifier, provided by the slave device <NUM>, to the controller <NUM>. In addition, the control unit <NUM> of the master device <NUM> also makes the second communications unit <NUM> transmit the device information of its own device, in association with the identifier of its own device, to the controller <NUM>.

Note that the "device information" as used herein is not information including the decision made by the control unit <NUM> that an internal event (such as replacement timing, malfunction, low battery level, or dirtiness) should be happening. In other words, the device information is not output at the very timing when the decision is made that the internal event should be happening but is output at regular intervals, for example, to the controller <NUM>. The device information is information about the second to fifth detection signals provided by the second to fifth detection units (<NUM>-<NUM>). The device information may be output to the controller <NUM> either almost as it is or after having been processed. The device information may be instantaneous values represented by the second to fifth detection signals or a value calculated based on a moving average (i.e., a moving average value).

The controller <NUM> may be implemented as, for example, a home energy management system (HEMS) controller as described above and may communicate with a plurality of electrical devices provided for the facility <NUM>. The plurality of electrical devices may include air conditioners and water heaters, for example. In this embodiment, the controller <NUM> may further communicate with the master device <NUM> (device 1A) provided for the facility <NUM>. In addition, the controller <NUM> may also communicate with the plurality of slave devices <NUM> (devices 1B-1E) via the master device <NUM>.

The controller <NUM> includes a control unit <NUM>, a communications unit <NUM>, a storage unit <NUM>, and a display unit <NUM> as shown in <FIG>. The controller <NUM> further includes an alert unit U1. In this embodiment, however, the display unit <NUM> corresponds to the alert unit U1 (see <FIG>).

The communications unit <NUM> includes a first (communications) interface 61A for communicating with the master device <NUM> and other devices. The first interface 61A receives various pieces of information from the master device <NUM> and other devices by wireless communication using a radio wave falling within the second frequency band (such as the <NUM> band). The communications unit <NUM> further includes a second (communications) interface 61B for communicating with the telecommunications device <NUM> and the external server <NUM> over a network NT1 (see <FIG>) such as the Internet. The second interface 61B may communicate with the telecommunications device <NUM> via another device such as the external server <NUM>. Examples of the telecommunications device <NUM> include the facility <NUM> user's (e.g., resident's) own smartphone, tablet terminal, or any other device with communication capability. In this embodiment, the telecommunications device <NUM> is supposed to be a smartphone. In the telecommunications device <NUM>, installed is a dedicated application software program that allows the telecommunications device <NUM> to wirelessly communicate with the controller <NUM>. The external server <NUM> is a server device corresponding to the contact address X1 (to be described later). In <FIG>, the number of the external server <NUM> provided is one. However, this is only an example of the present disclosure and should not be construed as limiting. Alternatively, a plurality of external servers <NUM> may be provided. That is to say, there may be a plurality of contact addresses X1.

The storage unit <NUM> is implemented as a device selected from the group consisting of a read-only memory (ROM), a random-access memory (RAM), an electrically erasable programmable read-only memory (EEPROM), and other storage devices.

The storage unit <NUM> stores the respective identifiers (identification information) of the plurality of devices <NUM>, for example. In addition, the storage unit <NUM> further stores information (such as email addresses and phone numbers) about the contact addresses X1, the telecommunications device <NUM>, and the server device managed by a security company, for example. Optionally, at least part of these pieces of information stored in the storage unit <NUM> may be stored in another device (such as an external server device provided outside of the facility <NUM>) separately from the controller <NUM>.

As shown in <FIG>, the control unit <NUM> includes an acquisition unit <NUM> and an output unit <NUM>. In other words, the control unit <NUM> performs the functions of the acquisition unit <NUM> and the output unit <NUM>.

In addition, the control unit <NUM> further includes a decision unit <NUM>, an instruction unit <NUM>, and a switching unit <NUM> as shown in <FIG>. In other words, the control unit <NUM> further performs the functions of the decision unit <NUM>, the instruction unit <NUM>, and the switching unit <NUM>.

The acquisition unit <NUM> is configured to acquire the detection information, providing notification that a fire has been detected in the facility <NUM>, from the master device <NUM> via the first interface 61A.

In addition, the acquisition unit <NUM> is also configured to acquire, from the device(s) <NUM>, the device information about the internal event that is going to happen to the device <NUM> itself (e.g., information about the replacement timing, malfunction, low battery level, and dirtiness in this embodiment). In this embodiment, a plurality of devices <NUM> are provided. The acquisition unit <NUM> acquires, from the master device <NUM> via the first interface 61A, the device information about the master device <NUM> itself and the device information about the four slave devices <NUM>. The acquisition unit <NUM> may acquire the device information about the five devices <NUM> either at a time or separately (i.e., at multiple different timings) from the master device <NUM>. The acquisition unit <NUM> may acquire the device information from the master device <NUM> at regular intervals, for example, but may also acquire the device information at an arbitrary timing. For example, the controller <NUM> may instruct the master device <NUM> to transmit the device information at the reception request from either the external server <NUM> or the telecommunications device <NUM>, for example.

In this embodiment, the acquisition unit <NUM> acquires, as the device information, a detection signal generated as a signal indicative of a particular event and provided by the detection unit <NUM> of any of the devices <NUM>, from the device <NUM>. In other words, the device <NUM> includes the detection unit <NUM> and the device information is information about the detection signal provided by the detection unit <NUM> as described above. In this embodiment, however, the detection signal is supposed to include the second to fifth detection signals provided by the second to fifth detection units <NUM>-<NUM> of the detection unit <NUM>. That is to say, the controller <NUM> receives, as the device information, the second to fifth detection signals generated as signals indicative of particular events, except a fire as an event that calls for disaster prevention measures, i.e., generated as signals indicative of the internal events.

The decision unit <NUM> determines, based on the second to fifth detection signals acquired by the acquisition unit <NUM>, whether or not the device <NUM> shows any early signs of an internal event.

Next, it will be described what the "early signs of an internal event" are. As described above, at a point in time when an internal event (which is any one of replacement timing, malfunction, low battery level, or dirtiness) is happening to its own device, the device <NUM> makes its own alert unit <NUM> call an alert to that effect. In contrast, the decision unit <NUM> determines, before a determination is made that the internal event should be happening, whether or not there any early signs of that internal event. In the following description, a value for use as a criterion for determining whether or not there are any early signs of the internal event will be hereinafter referred to as an "early signs value.

For example, regarding replacement timing, if a determination is made that the replacement timing should have come when the cumulative time of use has reached ten years, then the early signs are shown when the cumulative time of use has reached nine years and eleven months (which is an early signs value). Also, regarding malfunction, if a determination is made that the malfunction should have occurred at a point in time when the voltage value, for example, becomes less than a reference value, then the early signs are shown when the voltage value becomes less than a value (early signs value) that is greater than the reference value. Furthermore, regarding low battery level, if a determination is made that the battery should have run out when the battery level becomes less than <NUM>% of the capacity, then the early signs are shown when the battery level becomes less than <NUM>% (early signs value) of the capacity.

Regarding the dirtiness, if a determination is made that the degree of dirtiness should have reached a significant degree at a point in time when the minimum value of the smoke concentration during a predetermined period is equal to or greater than a first threshold value but less than a second threshold value, then the early signs are shown when the minimum value of the smoke concentration is equal to or greater than a third threshold value (early signs value), which is smaller than the first threshold value, but less than the first threshold value.

The decision unit <NUM> refers to, according to the type of the detection signal acquired from the master device <NUM>, the early signs value that is stored in advance in the storage unit <NUM>, thereby determining whether or not each device <NUM> shows any early signs of the internal event detected.

Optionally, the control unit <NUM> may accumulate, in the storage unit <NUM>, the device information of the respective devices <NUM> which has been received. The decision unit <NUM> may determine, based on the device information accumulated, whether or not each device <NUM> shows any early signs of the internal event. In other words, the decision unit <NUM> does not have to perform the decision processing at the timing when the device information is acquired. For example, if the device information is acquired once a day, then the decision processing may be performed once a month.

Optionally, the decision unit <NUM> may make various types of analysis based on the device information of the respective devices <NUM> that has been accumulated in the storage unit <NUM>. For example, when finding the rate of increase or decrease in a value shown by a detection signal of one device <NUM> steep enough, the control unit <NUM> may decide that early signs of an internal event should be shown.

The output unit <NUM> is configured to, when the acquisition unit <NUM> acquires the detection information, make the second interface 61B output (transmit) a notification that a fire is present in the facility <NUM> to a server device managed by a security company, for example.

In addition, the output unit <NUM> is also configured to output, based on the device information, early signs information about the early signs of an internal event. Specifically, the output unit <NUM> outputs early signs information, including the decision made by the decision unit <NUM>, to a predetermined external contact address X1. The contact address X1 is herein supposed to be, for example, an external server <NUM> managed by a builder (which is also called a "house maker" in Japan) or building contractor of the facility <NUM>. However, this is only an example of the present disclosure and should not be construed as limiting. Optionally, the contact address X1 may include the telecommunications device <NUM> owned by the user such as a resident of the facility <NUM>. The output unit <NUM> refers to the information, stored in the storage unit <NUM>, about the contact address X1 to make the second interface 61B output the early signs information.

The display unit <NUM> may be implemented as a thin display device such as a liquid crystal display (LCD) or an organic electroluminescent (OEL) display. The display unit <NUM> may display for example, the information acquired by the acquisition unit <NUM>. The display unit <NUM> corresponds to the alert unit U1 configured to, when the early signs information indicates that the device <NUM> shows some early signs of an internal event, alert the user (such as a resident) to that effect. The control unit <NUM> makes the display unit <NUM> indicate that there are some early signs of the internal event. Alternatively, the display unit <NUM> may display the device information acquired from the respective devices <NUM>, no matter whether there are any early signs or not. Optionally, the display unit <NUM> may display, as a graphic representation, the device information accumulated in the storage unit <NUM>. Providing the controller <NUM> with the alert unit U1 allows the controller <NUM> to alert the user to the early signs of the internal event that is going to happen to the device <NUM>.

In some cases, it may be known in advance to the user of the facility <NUM> that in a space (such as the space E5) where one device <NUM> is installed, a particular type of activity (such as cooking) that is highly likely to affect the device information output from the device <NUM> will be performed for a certain period of time. Specifically, if cooking involving a lot of smoke is carried out, for example, then the smoke concentration represented by the fifth detection signal could increase during the certain period of time.

To cope with this situation, the instruction unit <NUM> is configured to output, to the device <NUM>, the instruction information which used to selectively enable or disable the device <NUM> to output, or from outputting, the device information. On accepting an operating command from the user, the controller <NUM> makes the instruction unit <NUM> output instruction information in accordance with the operating command to the device <NUM> (master device <NUM>). If the display unit <NUM> is implemented as a touchscreen display device, for example, then the device <NUM> may be selectively enabled to output, or disabled from outputting, the device information (i.e., the device <NUM> may be switched from the output enabled state to the output disabled state, or vice versa) by performing a touch operation on the setting screen displayed on the display unit <NUM>. Alternatively, the device <NUM> may also be switched from the output enabled state to the output disabled state, or vice versa, in response to a press operation on an operating button provided beside the display unit <NUM>. Optionally, a switching period (e.g., from <NUM> o'clock to <NUM> o'clock) may also be specified. Furthermore, the target device <NUM> to be subjected to switching may be specified by its identifier or all devices <NUM> may be specified at a time.

On receiving, from the controller <NUM>, instruction information that a target device <NUM> should be disabled from outputting the device information, the master device <NUM> stops outputting the device information of the target device <NUM>. In other words, even when acquiring the device information from the target device <NUM>, the master device <NUM> does not output the device information to the controller <NUM>. Alternatively, the master device <NUM> may instruct the target device <NUM> to stop outputting the device information.

Providing the controller <NUM> with the instruction unit <NUM> facilitates stopping (or disabling) output of the device information from the device <NUM> either at the user's request or depending on the surrounding environment.

Meanwhile, the switching unit <NUM> is configured to selectively enable or disable the output unit <NUM> to output, or from outputting, the early signs information. On accepting an operating command from the user, the controller <NUM> may make the switching unit <NUM> selectively enable or disable the output unit <NUM> to output, or from outputting, the early signs information in accordance with the operating command. If the display unit <NUM> is implemented as a touchscreen display device, for example, then the output unit <NUM> may be selectively enabled to output, or disabled from outputting, the early signs information (i.e., the output unit <NUM> may be switched from the output enabled state to the output disabled state, or vice versa) in response to a touch operation on the setting screen displayed on the display unit <NUM>. Alternatively, the output unit <NUM> may also be switched from the output enabled state to the output disabled state, or vice versa, in response to a press operation on an operating button provided beside the display unit <NUM>. Optionally, a switching period may also be specified.

Providing the controller <NUM> with the switching unit <NUM> facilitates stopping (or disabling) output of the early signs information from the controller <NUM> either at the user's request or depending on the surrounding environment.

Optionally, the controller <NUM> may include only one, not both, of the instruction unit <NUM> and the switching unit <NUM>.

Next, it will be described briefly how the device management system <NUM> operates. In the following description, its operation will be described with reference to <FIG> with attention paid to only the degree of dirtiness of one slave device <NUM>.

The slave device <NUM> makes the fifth detection unit <NUM> of the detection unit <NUM> detect a smoke concentration (in Step ST1) and outputs, at <NUM> o'clock every day, device information including information about the fifth detection signal representing the smoke concentration of its own device, to the master device <NUM> (in Step ST2). The slave device <NUM> makes the first communications unit <NUM> output (transmit) the device information.

When acquiring the device information of the slave device <NUM> via the first communications unit <NUM>, the master device <NUM> makes the second communications unit <NUM> output (transmit) the device information to the controller <NUM> (in Step ST3).

Every time the controller <NUM> acquires the device information of the slave device <NUM>, the controller <NUM> stores the device information in the storage unit <NUM> to accumulate the device information of the slave device <NUM> (in Step ST4). The controller <NUM> makes the decision unit <NUM> determine, once a month (e.g., at <NUM> o'clock at the end of every month), based on the device information accumulated about the slave device <NUM>, whether or not the slave device <NUM> shows any early signs of the degree of dirtiness reaching a significant degree.

When finding the minimum value of the smoke concentration during the one-month period equal to or greater than the early signs value (third threshold value) but less than the first threshold value, for example, the controller <NUM> decides that there should be some early signs of the degree of dirtiness reaching a significant degree (in Step ST5). Then, the controller <NUM> provides the external server <NUM>, serving as the contact address X1, with the early signs information (in Step ST6).

By checking the early signs information received, the contact address X1 learns that the chances of a fire warning being emitted erroneously due to the significant degree of dirtiness are increasing in the particular slave device <NUM> at the facility <NUM> that is the source device of the early signs information. This allows a person at the contact address X1 to prompt the user of the slave device <NUM> to do maintenance of, or replace, the slave device <NUM> before a determination is made that the degree of dirtiness should have actually reached the significant of degree.

If the slave device <NUM> were used continuously without being maintained or replaced, then the degree of dirtiness thereof would further advance with the passage of time. Meanwhile, the slave device <NUM> itself monitors the fifth detection signal (representing the smoke concentration). When a determination is made that the degree of dirtiness should have reached the significant degree, its own alert unit <NUM> will emit an alert sound accompanied by a verbal warning message "Clean it. " In that case, the slave device <NUM> will also notify the controller <NUM>, via the master device <NUM>, of the decision that the degree of dirtiness should have reached the significant degree.

According to this sequence, the controller <NUM> (control system <NUM>) outputs the early signs information about the early signs of the degree of dirtiness (which is an exemplary internal event) of the device <NUM> reaching the significant degree. This allows the destination device (i.e., the contact address X1) to learn about the early signs of the internal event via the control system <NUM>. That is to say, this increases the chances of the user being notified of the early signs of the internal event by the contact address X1, not by the alert sound emitted from the device <NUM> itself. This allows the user to be provided with information about the status of the device <NUM> at an earlier time while reducing the chances of impairing the usefulness of the device <NUM>.

In addition, providing the controller <NUM> with the decision unit <NUM> for determining whether or not there are any early signs of the internal event allows the device <NUM> to have a simplified configuration, compared to a situation where the device <NUM> is provided with the function of determining whether or not the device <NUM> itself shows any early signs of the internal event.

Furthermore, the "internal event" herein refers to an event, of which the degree advances with the passage of time. Thus, the early signs of the internal event may be detected easily before the internal event happens. This allows the destination device (i.e., the contact address X1) to be notified easily of the early signs of the internal event.

Note that the embodiment described above is only an exemplary one of various embodiments of the present disclosure and should not be construed as limiting. Rather, the exemplary embodiment may be readily modified in various manners depending on a design choice or any other factor without departing from the scope of the present disclosure. The functions of the control system <NUM> and device <NUM> according to the exemplary embodiment described above may also be implemented as, for example, respective methods for controlling the control system <NUM> and the device <NUM>, a computer program, or a non-transitory storage medium that stores the computer program.

Next, variations of the exemplary embodiment will be enumerated one after another. The variations to be described below may be adopted in combination as appropriate. In the following description, the exemplary embodiment described above will be hereinafter sometimes referred to as a "basic example.

The control unit <NUM> of the control system <NUM> and the control unit <NUM> of the device <NUM> according to the present disclosure each include a computer system. The computer system may include, as principal hardware components, a processor and a memory. The functions of the control unit <NUM> of the control system <NUM> and the control unit <NUM> of the device <NUM> according to the present disclosure may be performed by making the processor execute a program stored in the memory of the computer system. The program may be stored in advance in the memory of the computer system. Alternatively, the program may also be downloaded through a telecommunications line or be distributed after having been recorded in some non-transitory storage medium such as a memory card, an optical disc, or a hard disk drive, any of which is readable for the computer system. The processor of the computer system may be made up of a single or a plurality of electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). As used herein, the "integrated circuit" such as an IC or an LSI is called by a different name depending on the degree of integration thereof. Examples of the integrated circuits include a system LSI, a very large-scale integrated circuit (VLSI), and an ultra large-scale integrated circuit (ULSI). Optionally, a field-programmable gate array (FPGA) to be programmed after an LSI has been fabricated or a reconfigurable logic device allowing the connections or circuit sections inside of an LSI to be reconfigured may also be adopted as the processor. Those electronic circuits may be either integrated together on a single chip or distributed on multiple chips, whichever is appropriate. Those multiple chips may be integrated together in a single device or distributed in multiple devices without limitation. As used herein, the "computer system" includes a microcontroller including one or more processors and one or more memories. Thus, the microcontroller may also be implemented as a single or a plurality of electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

Also, in the embodiment described above, the plurality of constituent elements (or the functions) of each of the control system <NUM> and the device <NUM> are integrated together in a single housing. However, this is not an essential configuration for the control system <NUM> or the device <NUM>. Alternatively, those constituent elements (or functions) of each of the control system <NUM> and the device <NUM> may be distributed in multiple different housings. Still alternatively, at least some functions of the control system <NUM> (e.g., some functions of the control system <NUM>) may be implemented as a cloud computing system as well. Likewise, at least some functions of the device <NUM> (e.g., some functions of the device <NUM>) may be implemented as a cloud computing system as well. Conversely, the plurality of functions of the control system <NUM> may be integrated together in a single housing as the controller <NUM> and the plurality of functions of the device <NUM> may be integrated together in a single housing as in the basic example described above.

The control unit <NUM> of the device <NUM> may be configured to determine, based on a detection signal generated as a signal indicative of a particular event and output by the detection unit <NUM> of its own device, whether or not the device <NUM> shows any early signs of the internal event. The control unit <NUM> of the master device <NUM> may also be configured to determine, based on the detection signals provided by the respective detection units <NUM> of its own device and the slave devices <NUM>, whether not only its own device but also the respective slave devices <NUM> show any early signs of the internal event. The device <NUM> (such as the master device <NUM>) may transmit the decision to the controller <NUM>. Meanwhile, the acquisition unit <NUM> of the controller <NUM> may be configured to acquire the decision as the device information from the device <NUM>.

The decision processing described above does not have to be performed by the controller <NUM> and the devices <NUM> but may also be performed by a server device provided outside of the facility <NUM>. In other words, the control system <NUM> may include the controller <NUM> and a single or a plurality of external server devices. In that case, the controller <NUM> may transfer the device information, acquired from any of the devices <NUM>, to one of the external server devices, receive the result of the decision processing performed by the external server device, and then output the early signs information to the contact address X1. Alternatively, while the controller <NUM> performs the decision processing as in the basic example described above, the controller <NUM> may transmit the decision to the external server device and the external server device may output the early signs information to the contact address X1. Optionally, the external server device may store the history of the early signs information associated with each facility <NUM>, the history of the device information, the early signs values, and other pieces of information and values.

In the basic example described above, the controller <NUM> outputs the early signs information, including the decision indicating whether or not the device <NUM> shows any early signs of the internal event, to the contact address X1. However, this is only an example of the present disclosure and should not be construed as limiting. Alternatively, the controller <NUM> may output not only the early signs information but also the device information acquired from the device <NUM> to the contact address X1 directly (i.e., the values represented by the respective detection signals or their corresponding information as they are). In addition, if a determination is made that the internal event should be happening, the controller <NUM> may output not only the early signs information but also determination information, indicating to that effect, to the contact address X1. If the determination information is output to the contact address X1, the alert unit <NUM> of the device <NUM> is highly likely to be alerting, or have alerted, the user to occurrence of the internal event.

In the basic example described above, only one early signs value is assigned to each internal event. However, this is only an example of the present disclosure and should not be construed as limiting. Alternatively, a plurality of early signs values may be assigned to each internal event. That is to say, the early signs before the degree of dirtiness is determined to have reached the significant degree may be classified into multiple stages. Specifically, the early signs values may include a first early signs value, a second early signs value, and a third early signs value. When finding the smoke concentration (indicating the degree of dirtiness) equal to or greater than the first early signs value but less than the second early signs value, the controller <NUM> may output, to the contact address X1, the early signs information indicating that the early signs have entered the first stage. Likewise, when finding the smoke concentration equal to or greater than the second early signs value but less than the third early signs value, the controller <NUM> may output, to the contact address X1, the early signs information indicating that the early signs have entered the second stage. Furthermore, when finding the smoke concentration equal to or greater than the third early signs value but less than the first threshold value, the controller <NUM> may output, to the contact address X1, the early signs information indicating that the early signs have entered the third stage.

Claim 1:
A device management system (<NUM>) comprising:
one or more devices (<NUM>);
a control system (<NUM>) connected to the one or more devices (<NUM>) to be ready to communicate with the one or more devices (<NUM>), wherein each of the one or more devices (<NUM>) are configured to detect a presence of an event that calls for disaster prevention measures;
wherein each of the one or more devices (<NUM>) comprises:
detection units (<NUM>, <NUM>, <NUM>, <NUM>) configured to output detection signals indicative to an internal event, the internal event including at least one of a timing to replace the device (<NUM>), a malfunction of the device (<NUM>), a low battery level of the device (<NUM>), dirtiness of the device (<NUM>), and an abnormal temperature inside the device (<NUM>),
a control unit (<NUM>) configured to monitor the detection signals output from the detection units (<NUM>, <NUM>, <NUM>, <NUM>) and determine, based on the detection signal, whether or not the internal event has occurred;
a communications unit (<NUM>) configured to transmit device information about the detection signals at regular intervals to the control system (<NUM>); and
an altert unit (<NUM>) configured to emit light or a sound alerting a user to the internal event when the determination is made by the control unit (<NUM>) that the internal event is happening to the device (<NUM>)
wherein the control system (<NUM>) comprises:
an acquisition unit (<NUM>) configured to acquire device information from the one or more devices (<NUM>);
a decision unit (<NUM>) configured to determine, based on the device information and before the determination is made by the control unit (<NUM>) that the internal event is happening to the respective device (<NUM>), whether or not the device (<NUM>) shows any early signs of the internal event; and
an output unit (<NUM>) configured to output to an external server (<NUM>) or telecommunications device (<NUM>) owned by the user of the one or the plurality of devices (<NUM>), early signs information about any early signs of the internal event, the early signs information including a decision made by the decision unit (<NUM>) and being based on the device information.