Equipment network system

Abstract

An air conditioning system (1) uses a master-terminal method, and comprises a plurality of outdoor units (2a-2c) and a plurality of indoor units (3a-3c). In the air conditioning system (1), one master unit is determined from among the plurality of outdoor units (2a-2c) on the basis of unique equipment information corresponding to each of the plurality of outdoor units (2a-2c), and all of the other equipment are determined as terminal units. Consequently, it becomes possible to reduce a risk that the entire system becomes inoperable when a failure such as an equipment fault occurs.

Description

Equipment Network System

[0001] The present disclosure relates to an equipment network system.

[0002] Known device network systems use a master-terminal system, such as the air conditioning system described in Patent Document 1. In the master-terminal system, there are devices that serve as masters to manage the network and terminals that are managed by the master, and one network is made up of one device that serves as the master (hereinafter referred to as the "master device") and all other devices that serve as terminals (hereinafter referred to as the "terminal devices").

[0003] In a network, terminal devices are managed by a master device, but their communication operations are not unilaterally controlled by the master device; terminal devices send data autonomously and can also communicate directly with each other. In this way, the master-terminal system is technically different from the so-called master-slave system, which is based on command / response.

[0004] Japanese Patent Application Laid-Open No. 2022-122850

[0005] The above-mentioned equipment network system is generally composed of one or more equipment (hereinafter referred to as the "first equipment group") that controls the operation of the system, such as outdoor units in an air conditioning system, and multiple equipment (hereinafter referred to as the "second equipment group") that does not play such a role, such as indoor units.

[0006] Normally, even if one of the devices in the second device group fails, it is unlikely that the entire system will become inoperable, but if the device in question is a master device, there will be no device to manage the network, and the entire system will become inoperable.

[0007] In order to reduce this risk, it is desirable to prevent a device belonging to the second device group from being selected as the master device (in other words, to have the master device selected from the first device group).However, the reality is that no significant technology has yet been proposed that allows the master device to be selected from the first device group without relying on human intervention.

[0008] The present disclosure has been made in consideration of the above-described circumstances, and aims to provide a device network system that can reduce the risk of the entire system becoming inoperable when a device failure occurs.

[0009] In order to achieve the above object, the equipment network system of the present disclosure is an equipment network system that uses a master-terminal method, and is equipped with a plurality of equipment including a first equipment group consisting of equipment that plays a role in controlling the operation of the equipment network system, and a second equipment group consisting of equipment that is not included in the first equipment group, and based on unique equipment information corresponding to each of the plurality of equipment, one master device is determined from the first equipment group, and all other equipment is determined to be terminal devices.

[0010] According to the present disclosure, it is possible to reduce the risk that the entire system will become inoperable when a device failure occurs.

[0011] FIG. 1 is a diagram showing the overall configuration of an air conditioning system in embodiment 1. Block diagram showing the hardware configuration of an outdoor unit in embodiment 1. Block diagram showing the hardware configuration of an indoor unit in embodiment 1. FIG. 2 is a diagram showing the functional configuration of an outdoor unit in embodiment 1. FIG. 3 is a diagram showing an example of a priority list in embodiment 1. FIG. 4 is a diagram showing the functional configuration of an indoor unit in embodiment 1. Flowchart showing the operation at system startup of an air conditioning system in embodiment 1. Flowchart showing the operation at startup of an outdoor unit in embodiment 1. Flowchart showing the operation of an outdoor unit when a failure occurs in the master unit in embodiment 1. Flowchart showing the operation of an indoor unit when a failure occurs in the master unit in embodiment 1. Flowchart showing the operation of an outdoor unit when the original master unit is restored in embodiment 1. Flowchart showing the operation of an indoor unit when the original master unit is restored in embodiment 1. FIG. 1 is a diagram showing the overall configuration of an air conditioning system. FIG. 2 is a block diagram showing the hardware configuration of a centralized controller in embodiment 2. FIG. 3 is a block diagram showing the hardware configuration of an outdoor unit in embodiment 2. FIG. 4 is a diagram showing the functional configuration of an outdoor unit in embodiment 2. FIG. 5 is a diagram showing an example of a priority list in embodiment 2. FIG. 6 is a diagram showing the functional configuration of a centralized controller in embodiment 2.

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0013] (Embodiment 1) Fig. 1 is a diagram showing the overall configuration of an air conditioning system 1 according to embodiment 1. The air conditioning system 1 is an example of an equipment network system according to the present disclosure. The air conditioning system 1 is a system that provides air conditioning for a building such as a building or store, and includes outdoor units 2a to 2c and indoor units 3a to 3c. In the air conditioning system 1, the devices (outdoor units 2a to 2c and indoor units 3a to 3c) communicate using a master-terminal system.

[0014] The outdoor units 2a-2c and the indoor units 3a-3c are examples of equipment according to the present disclosure. The outdoor units 2a-2c are examples of a first equipment group according to the present disclosure, and the indoor units 3a-3c are examples of a second equipment group according to the present disclosure. The outdoor units 2a-2c and the indoor units 3a-3c are connected to a transmission line 4 and via refrigerant piping (not shown) for circulating the refrigerant. That is, the outdoor units 2a-2c and the indoor units 3a-3c constitute a single refrigerant system. One of the outdoor units 2a-2c functions as a main outdoor unit, and the other outdoor units function as auxiliary outdoor units. As will be described in detail later, when the air conditioning system 1 is started up, each outdoor unit 2a-2c sets itself as either a main outdoor unit or an auxiliary outdoor unit based on an identification ID (identifier) ​​assigned to it in advance by a user and the identification IDs of the other outdoor units. Hereinafter, in explanations common to the outdoor units 2a to 2c, they will be referred to as outdoor unit 2 without any particular designation, and in explanations common to the indoor units 3a to 3c, they will be referred to as indoor unit 3 without any particular designation.

[0015] 2, the outdoor unit 2 has, as its hardware configuration, a control circuit 20, an auxiliary storage device 21, a communication control circuit 22, and a transmission / reception circuit 23. In addition, like a general outdoor unit, the outdoor unit 2 also has actuators such as a compressor, an outdoor fan, and an electronic expansion valve, and sensors such as a pipe temperature sensor that measures the temperature of the refrigerant pipes and an outdoor air temperature sensor, but these components will not be shown or described here.

[0016] The control circuit 20 is a microcontroller that performs overall control of the outdoor unit 2. The functions of the outdoor unit 2 realized by the control circuit 20 will be described in detail below. The auxiliary storage device 21 is configured with a readable / writable non-volatile semiconductor memory, such as an EPROM (Erasable Programmable Read-Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), or a flash memory. The auxiliary storage device 21 stores an outdoor unit program, which is a program for controlling the outdoor unit 2, and data used when the outdoor unit program is executed. The outdoor unit 2 can obtain the outdoor unit program or an update program for updating the outdoor unit program via communication from a server, terminal device, or the like (not shown), and store the program in the auxiliary storage device 21.

[0017] These programs can also be distributed by storing them on computer-readable recording media such as CD-ROMs (Compact Disc Read-Only Memory), DVDs (Digital Versatile Discs), magneto-optical discs, USB (Universal Serial Bus) memories, HDDs (Hard Disk Drives), SSDs (Solid-State Drives), and memory cards. When such a recording medium is directly or indirectly attached to the outdoor unit 2, the outdoor unit 2 can read the outdoor unit program or update program from the recording medium and store it in the auxiliary storage device 21.

[0018] The communication control circuit 22 is a microcontroller for controlling communication. The transmission / reception circuit 23 is a communication circuit equipped with a transmission circuit and a reception circuit, and transmits and receives signals to and from other outdoor units 2 and each indoor unit 3 via the transmission line 4 under the control of the communication control circuit 22.

[0019] 3, the indoor unit 3 has, as its hardware configuration, a control circuit 30, an auxiliary storage device 31, a communication control circuit 32, and a transmission / reception circuit 33. In addition, like a typical indoor unit, the indoor unit 3 also has actuators such as an indoor fan and an indoor solenoid valve, sensors such as a pipe temperature sensor that measures the temperature of the refrigerant pipes, and an indoor temperature sensor that measures the indoor temperature, but these configurations will not be shown or described here.

[0020] The control circuit 30 is a microcontroller that performs overall control of the indoor unit 3. The functions of the indoor unit 3 realized by the control circuit 30 will be described in detail below. The auxiliary storage device 31 is composed of, for example, a readable / writable non-volatile semiconductor memory such as an EPROM, EEPROM, or flash memory. The auxiliary storage device 31 stores an indoor unit program, which is a program for controlling the indoor unit 3, and data used when the indoor unit program is executed. The indoor unit 3 can obtain the indoor unit program or an update program for updating the indoor unit program via communication from a server, terminal device, etc. (not shown), and store the program in the auxiliary storage device 31.

[0021] These programs can also be stored and distributed on computer-readable recording media such as CD-ROMs, DVDs, magneto-optical disks, USB memories, HDDs, SSDs, memory cards, etc. When such a recording medium is directly or indirectly attached to the indoor unit 3, the indoor unit 3 can read the indoor unit program or update program from the recording medium and store it in the auxiliary storage device 31.

[0022] The communication control circuit 32 is a microcontroller for controlling communication. The transmission / reception circuit 33 is a communication circuit equipped with a transmission circuit and a reception circuit, and transmits and receives signals to and from the outdoor unit 2 and other indoor units 3 via the transmission line 4 under the control of the communication control circuit 32.

[0023] <Functional Configuration of Outdoor Unit 2> Next, characteristic functions of the outdoor unit 2 will be described. As shown in Fig. 4, the outdoor unit 2 has, as characteristic functions according to the present disclosure, a role determination unit 200, a main / sub setting unit 201, an equipment information collection unit 202, a priority setting unit 203, a recovery notification unit 204, and an operation switching unit 205. These functional units are realized by the control circuit 20 of the outdoor unit 2 executing the above-mentioned outdoor unit program stored in the auxiliary storage device 21. In addition to these, the outdoor unit 2 has functions for performing general operations in a master-terminal system, functions for performing operations similar to those of a general outdoor unit, etc., but description of these general functions will be omitted.

[0024] The role determination unit 200 determines the role of its own unit (i.e., the outdoor unit 2) to be one of the master unit, the alternative master unit, and the terminal unit. In detail, the role determination unit 200 determines its own role at each of the following times:

[0025] (1) At Start-Up When the power supply of the outdoor unit 2 is turned on (that is, when the outdoor unit 2 is started up), the role determination unit 200 determines its own role as a terminal unit.

[0026] (2) When a master unit is not detected (immediately after startup) If a master unit is not detected within a predetermined time (hereinafter referred to as the "first standby time") after startup, more specifically, if a signal periodically transmitted from the master unit (hereinafter referred to as the "master signal") is not received, the role determination unit 200 determines its own role as the master unit. The first standby time is longer than the transmission cycle of the master signal and is determined based on the MAC (Media Access Control) address of the outdoor unit 2, with the smaller the MAC address value, the shorter the first standby time. The first standby time of each outdoor unit 2 may be determined by the user and stored in advance in the auxiliary storage device 21 of each outdoor unit 2, or it may be determined by each outdoor unit 2 at startup based on its own MAC address.

[0027] (3) When the master unit is disconnected During operation, if a state in which the master signal cannot be received continues for a predetermined time (hereinafter referred to as the "second standby time") and if the unit's own priority is the second highest after the priority of the master unit, the role determination unit 200 determines its own role to be the alternate master unit. The length of the second standby time is the same for each outdoor unit 2 and is a time (for example, 5 minutes) that is sufficiently longer than the transmission cycle of the master signal. Details of the priority will be described later.

[0028] (4) When priority is set When the priority of each device including itself is set by the priority setting unit 203 described later, the role determination unit 200 determines its role to be the master device if its priority is the highest, and determines its role to be the terminal device if its priority is not the highest.

[0029] (5) When a priority list is received When a priority list (described later) is received from another outdoor unit 2, the role determination unit 200 refers to the received priority list, and if its own priority is the highest, it determines its own role to be the master unit, and if its own priority is not the highest, it determines its own role to be the terminal unit.

[0030] (6) When a restoration notification is received When the device itself is an alternative master device and receives a restoration notification from the previous master device, role determination section 200 determines its own role as a terminal device.

[0031] When the role of the outdoor unit 2 switches from a terminal unit to a master unit or an alternate master unit, the communication control circuit 22 of the outdoor unit 2 starts periodically transmitting a master signal via the transmission / reception circuit 23. The master signal is a notification signal such as a beacon frame or hello message, and is a signal for notifying the presence of a master unit on the network. Furthermore, when the role of the outdoor unit 2 switches from a master unit or an alternate master unit to a terminal unit, the communication control circuit 22 stops transmitting the master signal.

[0032] When started, the main / sub setting unit 201 sets itself as either a main outdoor unit or an auxiliary outdoor unit. In detail, after starting up and its own role is determined by the role determination unit 200, the main / sub setting unit 201 transmits the identification ID set for itself to the other outdoor units 2, and also receives the identification IDs sent from the other outdoor units 2. Then, if its own identification ID is smaller than the identification ID of any of the other outdoor units 2, the main / sub setting unit 201 sets itself as the main outdoor unit, and if its own identification ID is larger than the identification ID of any of the other outdoor units 2, it sets itself as the auxiliary outdoor unit.

[0033] When the device information collection unit 202 is set as the main outdoor unit by the main / sub setting unit 201, it collects device information from all devices other than itself. In detail, the device information collection unit 202 transmits a notification requesting device information (hereinafter referred to as an "device information request notification") to all devices other than itself. The device (outdoor unit 2 or indoor unit 3) that receives the device information request notification transmits its own device information to the main outdoor unit. The device information includes model information, an identification ID, and a MAC address. The model information is information that can identify the model of the device, and is, for example, information that indicates any one of the main outdoor unit, auxiliary outdoor unit, and indoor unit.

[0034] The device information collection unit 202 receives device information sent from each device (each outdoor unit 2 and each indoor unit 3) in response to the device information request notification, thereby collecting device information from all devices other than itself. The device information collection unit 202 stores the collected device information in the auxiliary storage device 21.

[0035] If the outdoor unit 2 itself (the outdoor unit 2) is the main outdoor unit, the priority setting unit 203 sets priorities for each device, including itself, based on its own device information and the collected device information for each device. Priorities are set according to predetermined rules depending on the role of each device in the air conditioning system 1, etc. Priorities are indicated by numerical values, with the higher the priority, the smaller the value. In this embodiment, the outdoor unit 2, which is a model that controls the operation of the refrigerant circuit in the air conditioning system 1, is set to have a higher priority than the indoor units 3, and further, the main outdoor unit is set to have a higher priority than the auxiliary outdoor unit. Furthermore, for devices of the same model, the smaller the value of the identification ID, the higher the priority is set.

[0036] After setting the priority of each device including itself, the priority setting unit 203 generates a priority list and transmits the generated priority list to each device. As shown in Fig. 5, the priority list is a list in which device information and priority are associated with each device.

[0037] If the outdoor unit 2 is a master unit that has temporarily left the air conditioning system 1 due to a failure or the like, and then recovers and joins the network of the alternative master unit as a terminal unit, the recovery notification unit 204 sends a recovery notification to each device indicating that the outdoor unit 2 has recovered.

[0038] When the master unit is separated from the air conditioning system 1 due to a malfunction or the like, in other words, when the unit itself or any of the other outdoor units 2 is switched to the substitute master unit, the operation switching unit 205 switches its own operation from normal operation (also referred to as normal operation) to emergency operation (also referred to as emergency operation). Emergency operation is an operation for continuing air conditioning operation with a reduced air conditioning capacity of the entire air conditioning system 1 compared to normal operation. Furthermore, when the master unit recovers, the operation switching unit 205 switches its own operation from emergency operation to normal operation.

[0039] <Functional configuration of indoor unit 3> Next, the characteristic functions of the indoor unit 3 will be described. As shown in Fig. 6, the indoor unit 3 has a role determination unit 300 and an operation switching unit 301 as characteristic functions according to the present disclosure. These functional units are realized by the control circuit 30 of the indoor unit 3 executing the above-mentioned indoor unit program stored in the auxiliary storage device 31. In addition to these, the indoor unit 3 has functions for performing general operations in the master-terminal system, functions for performing operations similar to those of a general indoor unit, etc., but a description of these general functions will be omitted.

[0040] The role determination unit 300 determines the role of itself (i.e., the indoor unit 3) as one of the master unit, the alternative master unit, and the terminal unit. In detail, when the indoor unit 3 is powered on (i.e., when the indoor unit 3 starts up), the role determination unit 300 determines its role as the terminal unit.

[0041] When the master unit is disconnected from the air conditioning system 1 due to a malfunction or the like, the operation switching unit 301 switches its own operation from normal operation to emergency operation. Specifically, when the time during which the master signal is not received from the master unit reaches a predetermined time (hereinafter referred to as the "third standby time"), the operation switching unit 301 switches its own operation from normal operation to emergency operation. The third standby time is a time sufficiently longer than the transmission cycle of the master signal, for example, five minutes. Furthermore, when the master unit recovers, the operation switching unit 301 switches its own operation from emergency operation to normal operation.

[0042] <Operation Flow at System Start-Up> FIG. 7 is a flowchart showing the operation of the air conditioning system 1 at system start-up.

[0043] (Step S100) All devices (all outdoor units 2 and all indoor units 3) determine their own role as terminal devices at startup. After that, the operation of the air conditioning system 1 transitions to step S101.

[0044] (Step S101) The outdoor unit 2 that first detects that there is no master unit, i.e., the outdoor unit 2 with the shortest first standby time described above, selects itself as the master unit. Hereinafter, the master unit selected here will be referred to as the temporary master unit. The temporary master unit periodically transmits a master signal. All other devices (i.e., all terminal devices) join the network of this temporary master unit, and thereafter, communication between the devices in the air conditioning system 1 becomes possible. After that, operation of the air conditioning system 1 transitions to step S102.

[0045] (Step S102) Each outdoor unit 2 sets itself as either the main outdoor unit or the auxiliary outdoor unit based on the identification ID of each outdoor unit 2. Thereafter, the operation of the air conditioning system 1 proceeds to step S103.

[0046] (Step S103) The main outdoor unit collects device information from each device. Upon receiving a device information request notification from the main outdoor unit, the sub outdoor unit and each indoor unit 3 transmit their own device information to the main outdoor unit. Thereafter, the operation of the air conditioning system 1 proceeds to step S104.

[0047] (Step S104) The main outdoor unit sets the priority of each device based on the device information of each device. After that, the operation of the air conditioning system 1 proceeds to step S105.

[0048] (Step S105) The main outdoor unit transmits the priority list to each device. After that, the operation of the air conditioning system 1 proceeds to step S106.

[0049] (Step S106) The outdoor unit 2 with the highest priority determines itself as the master unit. The other outdoor units 2 determine themselves as terminal units. The master unit periodically transmits a master signal. All other devices (i.e., all terminal units) join the network of the master unit. This completes the flow.

[0050] <Operation Flow When Starting Up the Outdoor Unit 2> FIG. 8 is a flowchart showing the operation when starting up the outdoor unit 2. As shown in FIG.

[0051] (Step S200) The outdoor unit 2 determines its own role as a terminal unit. After that, the operation of the outdoor unit 2 transitions to step S201.

[0052] (Step S201) It is determined whether or not a master unit exists in the air conditioning system 1. In detail, if the outdoor unit 2 cannot detect a master unit within a first waiting time after startup, more specifically, if it cannot receive a master signal from the master unit, it determines that a master unit does not exist, and if the outdoor unit 2 can detect a master unit within the first waiting time after startup, it determines that a master unit exists.

[0053] As described above, the first standby time is longer than the transmission cycle of the master signal and is determined based on the MAC address of the outdoor unit 2, with the smaller the MAC address value, the shorter the first standby time. In other words, the first standby time differs for each outdoor unit 2. If there is no master unit (step S201; YES), the operation of the outdoor unit 2 proceeds to step S202. If there is a master unit (step S201; NO), the operation of the outdoor unit 2 proceeds to step S203.

[0054] (Step S202) The outdoor unit 2 determines its own role as the master unit and starts cyclically transmitting a master signal. After that, the operation of the outdoor unit 2 proceeds to step S203.

[0055] (Step S203) The outdoor unit 2 sets itself as either the main outdoor unit or the auxiliary outdoor unit based on the identification ID of each outdoor unit 2. Thereafter, the operation of the outdoor unit 2 transitions to step S204.

[0056] (Step S204) The outdoor unit 2 determines whether it is the main outdoor unit. If it is the main outdoor unit (step S204; YES), the operation of the outdoor unit 2 proceeds to step S205. If it is not the main outdoor unit, that is, if it is an auxiliary outdoor unit (step S204; NO), the operation of the outdoor unit 2 proceeds to step S208.

[0057] (Step S205) The outdoor unit 2 collects device information from each device. After that, the operation of the outdoor unit 2 proceeds to step S206.

[0058] (Step S206) The outdoor unit 2 sets the priority of each device. After that, the operation of the outdoor unit 2 proceeds to step S207.

[0059] (Step S207) The outdoor unit 2 generates a priority list including device information and priorities of each device, and transmits the generated priority list to each device. After that, the operation of the outdoor unit 2 proceeds to step S208.

[0060] (Step S208) The outdoor unit 2 determines whether or not its own priority is the highest. If its own priority is the highest (Step S208; YES), the operation of the outdoor unit 2 proceeds to Step S209. If its own priority is not the highest (Step S208; NO), the operation of the outdoor unit 2 proceeds to Step S210.

[0061] (Step S209) The outdoor unit 2 determines its own role as the master unit, and this flow ends.

[0062] (Step S210) The outdoor unit 2 determines its own role as a terminal unit, and this flow ends.

[0063] <Operation Flow of Outdoor Unit 2 When a Failure Occurs in the Master Unit> FIG. 9 is a flowchart showing the operation of the outdoor unit 2 when a failure occurs in the master unit.

[0064] (Step S300) The outdoor unit 2 determines whether the time during which the master signal has not been received from the previous master unit has reached a certain time (i.e., a second standby time). If the time during which the master signal has not been received from the previous master unit has reached the certain time (step S300; YES), the operation of the outdoor unit 2 transitions to step S301. If the time during which the master signal has not been received from the previous master unit has not reached the certain time (step S300; NO), the outdoor unit 2 continues to make the determination in step S300.

[0065] (Step S301) The outdoor unit 2 determines whether its own priority is next highest after the priority of the previous master unit. If its own priority is next highest after the priority of the previous master unit (Step S301; YES), the operation of the outdoor unit 2 proceeds to Step S302. If its own priority is not next highest after the priority of the previous master unit (Step S301; NO), the operation of the outdoor unit 2 proceeds to Step S303.

[0066] (Step S302) The outdoor unit 2 switches its role from a terminal unit to an alternative master unit. After that, the operation of the outdoor unit 2 proceeds to step S303.

[0067] (Step S303) The outdoor unit 2 switches its own operation from normal operation to emergency operation, and this flow ends.

[0068] <Operation Flow of Indoor Unit 3 When a Failure Occurs in the Master Unit> FIG. 10 is a flowchart showing the operation of the indoor unit 3 when a failure occurs in the master unit.

[0069] (Step S400) The indoor unit 3 determines whether the time during which the master signal has not been received has reached a certain time (i.e., the third standby time). If the time during which the master signal has not been received has reached the certain time (Step S400; YES), the operation of the indoor unit 3 transitions to Step S401. If the time during which the master signal has not been received has not reached the certain time (Step S400; NO), the indoor unit 3 continues to make the determination in Step S400.

[0070] (Step S401) The indoor unit 3 switches its own operation from normal operation to emergency operation, and this flow ends.

[0071] 11 is a flowchart showing the operation of the outdoor unit 2 (more specifically, the outdoor unit 2 other than the original master unit) when the original master unit is restored. As described above, when the original master unit that was disconnected from the air conditioning system 1 due to a failure joins the network of the alternative master unit as a terminal unit after recovery, it sends a recovery notification to each device.

[0072] (Step S500) The outdoor unit 2 determines whether or not a recovery notification has been received. If a recovery notification has been received (Step S500; YES), the operation of the outdoor unit 2 proceeds to Step S501. If a recovery notification has not been received (Step S500; NO), the outdoor unit 2 continues to perform the determination in Step S500.

[0073] (Step S501) The outdoor unit 2 determines whether or not it is an alternative master unit. If it is an alternative master unit (step S501; YES), the operation of the outdoor unit 2 proceeds to step S502. If it is not an alternative master unit (step S501; NO), the operation of the outdoor unit 2 proceeds to step S503.

[0074] (Step S502) The outdoor unit 2 switches its role from the alternative master unit to the terminal unit. After that, the operation of the outdoor unit 2 proceeds to step S503.

[0075] (Step S503) After the network is restored by the original master unit, the outdoor unit 2 switches its own operation from emergency operation to normal operation, and this flow ends.

[0076] <Operation Flow of Indoor Unit 3 When Former Master Unit Has Been Restored> FIG. 12 is a flowchart showing the operation of the indoor unit 3 when the former master unit has been restored.

[0077] (Step S600) The indoor unit 3 determines whether or not a recovery notification has been received. If a recovery notification has been received (Step S600; YES), the operation of the indoor unit 3 proceeds to Step S601. If a recovery notification has not been received (Step S600; NO), the indoor unit 3 continues to perform the determination in Step S600.

[0078] (Step S601) After the network is restored by the original master unit, the indoor unit 3 switches its own operation from emergency operation to normal operation, and then this flow ends.

[0079] As described above, in the air conditioning system 1 of this embodiment, one of the outdoor units 2a to 2c (i.e., the first device group) is designated as the master device based on device information specific to each device, and all other devices are designated as terminal devices. This allows the outdoor unit 2 to continue operating the air conditioning system 1 even if a failure occurs in the indoor unit 3 and communication becomes impossible. In other words, it is possible to reduce the risk that the entire air conditioning system 1 will become inoperable when a device failure occurs.

[0080] The device information also includes model information that identifies the model of each device. This allows a master unit to be determined based on the role of each device in the air conditioning system 1, where the roles differ depending on the model, and therefore a master unit can be determined from among the outdoor units 2a to 2c that play a role in controlling the operation of the refrigerant circuit in the air conditioning system 1.

[0081] The device information also includes an identification ID that can uniquely identify each device. This allows a unique device to be determined as the master device in an air conditioning system 1 that includes multiple devices of the same model.

[0082] In addition, the master device periodically transmits a master signal to notify other devices that it exists on the network, and if a state in which a master signal from the master device is not received continues for a predetermined period of time or longer, the terminal device with the highest priority among all the terminal devices switches itself over to the alternate master device. As a result, even if a failure occurs in the master device and communication becomes impossible, an alternate master device can be selected from among the terminal devices, allowing communication operations of the air conditioning system 1 to continue.

[0083] Furthermore, the priority of each device is set based on the device information, with the outdoor unit 2 being set to have a higher priority than the indoor unit 3. This makes it possible to determine another outdoor unit 2 as an alternative master unit when a failure occurs in the master unit, further reducing the risk of the entire air conditioning system 1 becoming inoperable when a device failure occurs.

[0084] Furthermore, each outdoor unit 2 starts up as a terminal unit, and if it receives a master signal from the alternative master unit within a predetermined time, it joins the network of the alternative master unit. As a result, even if a failure occurs in the outdoor unit 2 that serves as the master unit and it leaves the network, by restarting the outdoor unit 2 after the failure is recovered, the outdoor unit 2 can join the network of the alternative master unit and resume communication with other devices.

[0085] Furthermore, after the outdoor unit 2, the original master unit, joins the network of the alternative master unit, it sends a recovery notification to each device indicating that its own failure has been recovered and switches over to the master unit, and upon receiving the recovery notification, the alternative master unit switches over to the terminal unit. As a result, even if the outdoor unit 2, the master unit, fails and leaves the network, after recovery, the network can be reconstructed with the outdoor unit 2 as the master unit, and the network state of the air conditioning system 1 can be restored to the state it was in before the failure occurred.

[0086] Furthermore, if any outdoor unit 2 and any indoor unit 3 switches to an alternative master unit during normal operation under air conditioning control, the outdoor unit 2 and any indoor unit 3 will switch to emergency operation with reduced heating and cooling capacity compared to normal operation, and continue operation of the air conditioning system 1. This makes it possible to continue operation of the air conditioning system 1 more reliably even if a failure occurs in the master unit and communication becomes impossible.

[0087] (Variation 1) The method for determining the first standby time is an arbitrary design matter; for example, the larger the MAC address value, the shorter the time may be. The method for setting the main / auxiliary outdoor unit in the main / auxiliary setting unit 201 is also an arbitrary design matter; for example, the main / auxiliary setting unit 201 may set itself as the main outdoor unit if its own identification ID is the largest among all outdoor units 2, and may set itself as the auxiliary outdoor unit if its own identification ID is not the largest. The method for setting priority for units of the same model is also an arbitrary design matter; for example, the priority setting unit 203 may set it so that the larger the identification ID value, the higher the priority.

[0088] (Variation 2) In the first embodiment, the main outdoor unit sets the priority of each device and transmits a priority list to each device. However, each device may set its own priority and the priority of other devices. In detail, for example, the main outdoor unit may transmit to each device a device information list including its own device information and device information collected from each device, and each device may set the priority of each device based on the received device information list using a method similar to that used by the priority setting unit 203. Alternatively, each device may transmit its own device information to each of the other devices, and each device may set the priority of each device based on its own device information and the device information received from the other devices using a method similar to that used by the priority setting unit 203. Furthermore, if there are no overlapping models in the air conditioning system 1, each device may set its own priority based on its own device information and transmit information indicating its set priority to each of the other devices.

[0089] (Variation 3) In the first embodiment, an example was described in which, when the master unit becomes unable to communicate, the terminal unit with the highest priority becomes the substitute master unit. However, for example, if a failure occurs in the compressor of the outdoor unit 2, which serves as the master unit, the master unit may be able to communicate, but it may be difficult to continue operating the air conditioning system 1. In this case, it is desirable to immediately select a substitute master unit and transition to emergency operation. Therefore, in this variation, when a failure occurs in the master unit itself, the master unit switches itself from the master unit to a terminal unit. As a result, even if the master unit that has become unable to continue operating the system due to a failure is able to communicate, a substitute master unit is immediately selected, making it possible to more reliably reduce the risk of the entire air conditioning system 1 becoming inoperable.

[0090] (Variation 4) If a failure occurs in the master device, the master device may send a failure notification to each device informing them of the failure and switch over to a terminal device. The failure notification may be data notifying only the presence or absence of a failure, or data notifying the details of the failure, as long as each terminal device can confirm that a failure has occurred in the master device. In this case, upon receiving the failure notification, the terminal device immediately determines whether its priority is second only to the master device, and if it determines that its priority is second only to the master device, it switches over to the alternate master device. In this way, since the alternate master device is determined immediately, the risk of the entire air conditioning system 1 becoming inoperable can be more reliably reduced.

[0091] (Modification 5) The device network system according to the present disclosure can be applied not only to air conditioning systems but also to various other systems, such as a lighting system configured with a plurality of lighting devices.

[0092] (Variation 6) All or part of the functional units (see FIG. 4) of the outdoor unit 2 may be realized by dedicated hardware. Also, all or part of the functional units (see FIG. 6) of the indoor unit 3 may be realized by dedicated hardware. Examples of dedicated hardware include a single circuit, a composite circuit, a programmed processor, an ASIC (Application-Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination of these.

[0093] The technical ideas according to the above-described modifications may be realized independently or in appropriate combination.

[0094] 13 is a diagram showing the overall configuration of an air conditioning system 10 according to embodiment 2. The air conditioning system 10 is an example of an equipment network system according to the present disclosure. The air conditioning system 10 is a system for providing air conditioning for a building such as a building or a store, and includes a centralized controller 5, outdoor units 6a to 6g, and indoor units 7a to 7i.

[0095] <Centralized controller 5> The centralized controller 5 is a device for centrally controlling the multiple devices (i.e., outdoor units 6a to 6g and indoor units 7a to 7i) that make up the air conditioning system 10, and is installed in a location that is off-limits to unauthorized personnel, such as a control room within the building. As shown in Fig. 14, the centralized controller 5 has, as its hardware configuration, a control circuit 50, an auxiliary storage device 51, a communication interface 52, an operation reception unit 53, and a display 54.

[0096] The control circuit 50 is configured to include a CPU (Central Processing Unit), ROM (Read-Only Memory), RAM (Random-Access Memory), etc., and performs overall control of the centralized controller 5. The functions of the centralized controller 5 realized by the control circuit 50 will be described in detail below. The auxiliary storage device 51 is configured with a readable / writable nonvolatile semiconductor memory, a HDD, etc. Examples of the readable / writable nonvolatile semiconductor memory include an EPROM, an EEPROM, and a flash memory. The auxiliary storage device 51 stores a centralized control program, which is a program for centrally controlling the devices that make up the air conditioning system 10, and data used when the centralized control program is executed.

[0097] The communication interface 52 is an interface for communicating with each outdoor unit (6a, 6d, 6f) connected to the transmission line 8, which is a centralized transmission line. Hereinafter, a network made up of each device connected to the centralized transmission line will be referred to as a centralized network. The operation reception unit 53 includes one or more input devices, such as a keyboard, mouse, keypad, push button, touch panel, or touchpad, and receives input operations from a user and outputs signals related to the received input operations to the control circuit 50. The display 54 includes a display device, such as a liquid crystal display or an organic EL (electroluminescence) display. Under the control of the control circuit 50, the display 54 displays a screen for monitoring the operation of each device constituting the air conditioning system 10, a screen for controlling each device, and the like.

[0098] <Outdoor Units 6a-6g, Indoor Units 7a-7i> The outdoor units 6a-6g and indoor units 7a-7i are examples of equipment according to the present disclosure. The outdoor units 6a-6g are examples of a first equipment group according to the present disclosure, and the indoor units 7a-7i are examples of a second equipment group according to the present disclosure. The outdoor units 6a-6c and the indoor units 7a-7c are connected to a transmission line 9a, which is an indoor / outdoor transmission line, and are also connected via a first refrigerant pipe (not shown) for circulating the refrigerant. In other words, the outdoor units 6a-6c and the indoor units 7a-7c constitute a single refrigerant system, refrigerant system A. The outdoor unit 6a is connected to a centralized network. One of the outdoor units 6a-6c functions as a main outdoor unit, and the others function as auxiliary outdoor units.

[0099] The outdoor units 6d to 6e and the indoor units 7d to 7f are connected to a transmission line 9b, which is an indoor / outdoor transmission line, and are also connected via a second refrigerant pipe (not shown), which is different from the first refrigerant pipe. In other words, the outdoor units 6d to 6e and the indoor units 7d to 7f constitute a single refrigerant system, refrigerant system B. The outdoor unit 6d is also connected to a centralized network. Any one of the outdoor units 6d to 6e functions as the main outdoor unit, and the others function as auxiliary outdoor units.

[0100] The outdoor units 6f to 6g and the indoor units 7g to 7i are connected to a transmission line 9c, which is an indoor / outdoor transmission line, and are also connected via a third refrigerant pipe (not shown), which is different from the first refrigerant pipe and the second refrigerant pipe. That is, the outdoor units 6f to 6g and the indoor units 7g to 7i constitute a single refrigerant system, refrigerant system C. The outdoor unit 6f is also connected to a centralized network. Any one of the outdoor units 6f to 6g functions as the main outdoor unit, and the others function as auxiliary outdoor units.

[0101] Hereinafter, in explanations common to outdoor units 6a to 6g, they will be referred to as outdoor unit 6 without any particular designation of the individual units, in explanations common to indoor units 7a to 7i they will be referred to as indoor unit 7 without any particular designation of the individual units, and in explanations common to transmission lines 9a to 9c they will be referred to as transmission line 9 without any particular designation of the individual units.

[0102] 15 , the outdoor unit 6 includes, as hardware components, a control circuit 60, an auxiliary storage device 61, a communication control circuit 62, a first transmission / reception circuit 63, and a second transmission / reception circuit 64. In addition, like a typical outdoor unit, the outdoor unit 6 includes actuators such as a compressor, an outdoor fan, and an electronic expansion valve, as well as sensors such as a pipe temperature sensor that measures the temperature of the refrigerant pipes and an outdoor air temperature sensor, but these components will not be shown or described here.

[0103] The control circuit 60 is a microcontroller that performs overall control of the outdoor unit 6. The functions of the outdoor unit 6 realized by the control circuit 60 will be described in detail below. The auxiliary storage device 61 is composed of, for example, a readable / writable non-volatile semiconductor memory such as an EPROM, EEPROM, or flash memory. The auxiliary storage device 61 stores an outdoor unit program, which is a program for controlling the outdoor unit 6, and data used when executing the outdoor unit program. The outdoor unit 6 can obtain the outdoor unit program or an update program for updating the outdoor unit program from a central controller, a server (not shown), a terminal device, etc. via communication, and store the program in the auxiliary storage device 61.

[0104] These programs can also be distributed by storing them on computer-readable recording media such as CD-ROMs, DVDs, magneto-optical disks, USB memories, HDDs, SSDs, memory cards, etc. When such a recording medium is directly or indirectly attached to the outdoor unit 6, the outdoor unit 6 can read the outdoor unit program or update program from the recording medium and store it in the auxiliary storage device 61.

[0105] The communication control circuit 62 is a microcontroller for controlling communication. The first transmission / reception circuit 63 is a communication circuit equipped with a transmission circuit and a reception circuit, and is connected to the transmission line 8 via the first port P1, and transmits and receives signals to and from the centralized controller 5 and other outdoor units 6 under the control of the communication control circuit 62. The second transmission / reception circuit 64 is a communication circuit equipped with a transmission circuit and a reception circuit, and is connected to the transmission line 9 via the second port P2, and transmits and receives signals to and from other outdoor units 6 and each indoor unit 7 in the same refrigerant system as the second transmission / reception circuit 64 under the control of the communication control circuit 62.

[0106] <<Indoor Unit 7>> The hardware configuration and functional configuration of the indoor unit 7 are similar to those of the indoor unit 3 of the first embodiment (see Figs. 3 and 6).

[0107] <Functional Configuration of Outdoor Unit 6> Next, characteristic functions of the outdoor unit 6 will be described. The outdoor unit 6 has the same configuration as the outdoor unit 2 of Embodiment 1 (see FIG. 4 ), and performs the same operations as the outdoor unit 2 of Embodiment 1 in the refrigerant system to which it belongs. Furthermore, as shown in FIG. 16 , the outdoor unit 6 connected to the centralized network has a role determination unit 600, a representative outdoor unit setting unit 601, an equipment information collection unit 602, a priority setting unit 603, and a recovery notification unit 604. The functional units shown in FIGS. 4 and 16 are realized by the control circuit 60 of the outdoor unit 6 executing the above-mentioned outdoor unit program stored in the auxiliary storage device 61. In addition to these, the outdoor unit 6 has functions for performing general operations in the master-terminal system, functions for performing operations similar to those of a general outdoor unit, etc., but a description of these general functions will be omitted.

[0108] The role determination unit 600 determines the role of itself (i.e., the outdoor unit 6) in the centralized network as one of the master unit, the alternate master unit, and the terminal unit. In detail, the role determination unit 600 determines its own role at each of the following times:

[0109] (1) At Start-Up When the power of the outdoor unit 6 is turned on (that is, when the outdoor unit 6 is started up), the role determination unit 600 determines its own role as a terminal unit.

[0110] (2) When a master unit is not detected (immediately after startup) If a master unit is not detected within a predetermined time (hereinafter referred to as the "fourth standby time") after startup, more specifically, if a master signal, which is a signal transmitted periodically from the master unit, is not received, the role determination unit 600 determines its own role to be the master unit. The fourth standby time is longer than the transmission cycle of the master signal and is determined based on the MAC address of the outdoor unit 6; the smaller the MAC address value, the shorter the time.

[0111] (3) When the master unit is disconnected During operation, if a state in which the master signal cannot be received continues for a predetermined time (hereinafter referred to as the "fifth standby time") and if the unit's own priority is the second highest after the priority of the master unit, the role determination unit 600 determines its own role to be the alternate master unit. The length of the fifth standby time is the same for each outdoor unit 6 and is a time (for example, 5 minutes) that is sufficiently longer than the transmission cycle of the master signal. Details of the priority will be described later.

[0112] (4) When priority is set When the priority of each device in the centralized network, including the device itself, is set by the priority setting unit 603 described later, the role determination unit 600 determines its role to be the master device if its own priority is the highest, and determines its role to be the terminal device if its own priority is not the highest.

[0113] (5) When a priority list is received When a priority list (described later) is received from another outdoor unit 6, the role determination unit 600 refers to the received priority list, and if its own priority is the highest, it determines its own role to be the master unit, and if its own priority is not the highest, it determines its own role to be the terminal unit.

[0114] (6) When a restoration notification is received When the device itself is the alternative master device and receives a restoration notification from the previous master device, the role determination unit 600 determines its own role as a terminal device.

[0115] When the role of the outdoor unit 6 in the centralized network switches from a terminal unit to a master unit or an alternate master unit, the communication control circuit 62 of the outdoor unit 6 starts periodically transmitting a master signal via the first transmission / reception circuit 63. The master signal is a notification signal such as a beacon frame or hello message, and is a signal for notifying the presence of a master unit on the network. Furthermore, when the role of the outdoor unit 6 in the centralized network switches from a master unit or an alternate master unit to a terminal unit, the communication control circuit 62 stops transmitting the master signal.

[0116] At startup, the representative outdoor unit setting unit 601 acquires an identification ID from each outdoor unit 6 connected to the centralized network, and if its own identification ID is smaller than the identification ID of any other outdoor unit 6 in the centralized network, it sets itself as the representative outdoor unit.

[0117] When the device information collection unit 602 is set as the representative outdoor unit, it collects device information from all devices connected to the centralized network except for itself. In detail, the device information collection unit 602 transmits a device information request notice, which is a notice requesting device information, to all devices except for itself. A device (centralized controller 5 or outdoor unit 6) that receives the device information request notice transmits its own device information to the representative outdoor unit. The device information includes model information, an identification ID, and a MAC address. The model information is information that can identify the model of the device, and is, for example, information indicating any one of the representative outdoor unit, an outdoor unit (other than the representative outdoor unit), and the centralized controller.

[0118] In response to the device information request notification, the device information collection unit 602 receives device information sent from each device connected to the centralized network, thereby collecting device information from all devices connected to the centralized network except for itself. The device information collection unit 602 stores the collected device information in the auxiliary storage device 61.

[0119] When the outdoor unit 603 itself (the outdoor unit 2) is the representative outdoor unit, the priority setting unit 603 sets priorities for each device connected to the centralized network, including itself, based on its own device information and the collected device information for each device. Priorities are set according to predetermined rules depending on the role of each device connected to the centralized network of the air conditioning system 10. Priorities are indicated by numerical values, with higher priority values ​​being lower. In this embodiment, the outdoor unit 6, which is a model that controls the operation of the refrigerant circuit in the air conditioning system 10, is set to have a higher priority than the centralized controller 5, and the representative outdoor unit is set to have a higher priority than the other outdoor units 6. In addition, for devices of the same model, the smaller the identification ID value, the higher the priority is set.

[0120] The priority setting unit 603 sets the priority of each device connected to the centralized network, including itself, and then generates a priority list and transmits the generated priority list to each device connected to the centralized network. As shown in Fig. 17, the priority list is a list in which device information and priority are associated with each device.

[0121] If the outdoor unit 6 is a master unit that has temporarily disconnected from the air conditioning system 10 due to a failure or the like, and then recovers and joins the network of the alternative master unit as a terminal unit, the recovery notification unit 604 sends a recovery notification to each device connected to the centralized network indicating that the outdoor unit 6 has recovered.

[0122] <Functional Configuration of Centralized Controller 5> Next, a description will be given of characteristic functions of the centralized controller 5. As shown in Fig. 18 , the centralized controller 5 includes a roll determination unit 500, a driving data collection unit 501, a driving data display unit 502, an equipment control unit 503, and a notification unit 504. These functional units are realized by the control circuit 50 of the centralized controller 5 executing the above-mentioned centralized control program stored in the auxiliary storage device 51.

[0123] The role determination unit 500 determines the role of itself (i.e., the centralized controller 5) to be one of a master device, an alternative master device, and a terminal device. In detail, when the centralized controller 5 is powered on (i.e., when the centralized controller 5 starts up), the role determination unit 500 determines its own role to be a terminal device.

[0124] The operating data collection unit 501 periodically (for example, every minute) collects operating data from each device (i.e., each of the outdoor units 6a to 6g and each of the indoor units 7a to 7i). The operating data display unit 502 displays the collected operating data in a predetermined format on the display 54. The device control unit 503 controls the operation of each of the outdoor units 6a to 6g and each of the indoor units 7a to 7i in accordance with operating conditions previously set by the building owner, system administrator, etc., a previously registered operating schedule, etc.

[0125] When the master unit of the centralized network is disconnected from the air conditioning system 10 due to a malfunction or the like, the notification unit 504 notifies the user of the occurrence of the abnormality via the display 54. Furthermore, when the original master unit is restored and the network controlled by that master unit is restored, the notification unit 504 notifies the user of the display 54 that the master unit has been restored.

[0126] <Operation Flow at System Start-Up> Fig. 19 is a flowchart showing the operation at system start-up of the air conditioning system 10. Note that, at system start-up, each refrigerant system of the air conditioning system 10 performs the same operation as the air conditioning system 1 in the first embodiment (see Fig. 7), but a description of this operation will be omitted.

[0127] (Step S700) All devices connected to the centralized network determine their own role as terminal devices at startup. After that, the operation of the air conditioning system 10 transitions to step S701.

[0128] (Step S701) The outdoor unit 6 that first detects that there is no master unit, i.e., the outdoor unit 6 with the shortest fourth standby time described above, selects itself as the master unit. Hereinafter, the master unit selected here will be referred to as the temporary master unit. The temporary master unit periodically transmits a master signal via the transmission line 8. All other devices connected to the transmission line 8 (i.e., all terminal devices) join the network of this temporary master unit, and thereafter, communication between the devices in the centralized network of the air conditioning system 10 becomes possible. After that, the operation of the air conditioning system 10 proceeds to step S702.

[0129] (Step S702) The outdoor unit 6 with the smallest identification ID sets itself as the representative outdoor unit. After that, the operation of the air conditioning system 10 proceeds to step S703.

[0130] (Step S703) The representative outdoor unit collects device information from each device connected to the transmission line 8. When outdoor units 6 other than the representative outdoor unit and the centralized controller 5 receive a device information request notification from the representative outdoor unit, they transmit their own device information to the representative outdoor unit. Thereafter, the operation of the air conditioning system 10 transitions to step S704.

[0131] (Step S704) The representative outdoor unit sets the priority of each device based on the device information of each device. After that, the operation of the air conditioning system 10 proceeds to step S705.

[0132] (Step S705) The representative outdoor unit transmits the priority list to each device. After that, the operation of the air conditioning system 10 proceeds to step S706.

[0133] (Step S706) The outdoor unit 6 with the highest priority determines itself as the master unit. The other outdoor units 6 determine themselves as terminal units. The master unit periodically transmits a master signal. All other devices (i.e., all terminal units) join the network of the master unit. This completes the flow.

[0134] <Operation flow at startup of outdoor unit 6> Fig. 20 is a flowchart showing the operation at startup of the outdoor unit 6 connected to the transmission line 8. Note that at startup, each outdoor unit 6 performs the same operation as each outdoor unit 2 in embodiment 1 (see Fig. 8), but a description of this operation will be omitted.

[0135] (Step S800) The outdoor unit 6 determines its own role as a terminal unit. After that, the operation of the outdoor unit 6 transitions to step S801.

[0136] (Step S801) The outdoor unit 6 determines whether or not a master unit exists in the centralized network. Specifically, if the outdoor unit 6 cannot detect a master unit within a fourth waiting time after startup, or more specifically, if the outdoor unit 6 cannot receive a master signal from the master unit, it determines that no master unit exists. However, if the outdoor unit 6 can detect a master unit within the fourth waiting time after startup, it determines that a master unit exists.

[0137] As described above, the fourth standby time is longer than the transmission cycle of the master signal and is determined based on the MAC address of the outdoor unit 6, with the smaller the MAC address value, the shorter the fourth standby time. In other words, the fourth standby time differs for each outdoor unit 6. If there is no master unit (step S801; YES), the operation of the outdoor unit 6 proceeds to step S802. If there is a master unit (step S801; NO), the operation of the outdoor unit 6 proceeds to step S803.

[0138] (Step S802) The outdoor unit 6 determines its own role as the master unit and starts cyclically transmitting a master signal. After that, the operation of the outdoor unit 6 proceeds to step S803.

[0139] (Step S803) The outdoor unit 6 determines whether its own identification ID is the smallest among all outdoor units 6 connected to the centralized network. If its own identification ID is the smallest (step S803; YES), the operation of the outdoor unit 6 proceeds to step S804. If its own identification ID is not the smallest (step S803; NO), the operation of the outdoor unit 6 proceeds to step S805.

[0140] (Step S804) The outdoor unit 6 sets itself as the representative outdoor unit. After that, the operation of the outdoor unit 6 transitions to step S805.

[0141] (Step S805) The outdoor unit 6 determines whether or not it is the representative outdoor unit. If it is the representative outdoor unit (step S805; YES), the operation of the outdoor unit 6 proceeds to step S806. If it is not the representative outdoor unit (step S805; NO), the operation of the outdoor unit 6 proceeds to step S809.

[0142] (Step S806) The outdoor unit 6 collects device information from each device connected to the centralized network. After that, the operation of the outdoor unit 6 proceeds to step S807.

[0143] (Step S807) The outdoor unit 6 sets the priority of each device. After that, the operation of the outdoor unit 6 proceeds to step S808.

[0144] (Step S808) The outdoor unit 6 generates a priority list including device information and priorities of each device, and transmits the generated priority list to each device. After that, the operation of the outdoor unit 6 proceeds to step S809.

[0145] (Step S809) The outdoor unit 6 determines whether or not its own priority is the highest. If its own priority is the highest (step S809; YES), the operation of the outdoor unit 6 proceeds to step S810. If its own priority is not the highest (step S809; NO), the operation of the outdoor unit 6 proceeds to step S811.

[0146] (Step S810) The outdoor unit 6 determines its own role as the master unit, and this flow ends.

[0147] (Step S811) The outdoor unit 6 determines its own role as a terminal unit, and this flow ends.

[0148] <Operation Flow of the Outdoor Unit 6 When a Failure Occurs in the Master Unit> FIG. 21 is a flowchart showing the operation of the outdoor unit 6 when a failure occurs in the master unit of the centralized network.

[0149] (Step S900) The outdoor unit 6 determines whether the time during which the master signal has not been received from the previous master unit has reached a certain time (i.e., the fifth standby time). If the time during which the master signal has not been received from the previous master unit has reached the certain time (step S900; YES), the operation of the outdoor unit 6 transitions to step S901. If the time during which the master signal has not been received from the previous master unit has not reached the certain time (step S900; NO), the outdoor unit 6 continues to make the determination in step S900.

[0150] (Step S901) The outdoor unit 6 determines whether its own priority is next highest after the priority of the previous master unit. If its own priority is next highest after the priority of the previous master unit (step S901; YES), the operation of the outdoor unit 6 proceeds to step S902. If its own priority is not next highest after the priority of the previous master unit (step S901; NO), this flow ends.

[0151] (Step S902) The outdoor unit 6 switches its role from a terminal unit to an alternative master unit, and this flow ends.

[0152] <Operation Flow of the Centralized Controller 5 When a Failure Occurs in the Master Device> FIG. 22 is a flowchart showing the operation of the centralized controller 5 when a failure occurs in the master device of the centralized network.

[0153] (Step S1000) The centralized controller 5 determines whether the time during which the master signal has not been received has reached a certain time (e.g., a fifth waiting time). If the time during which the master signal has not been received has reached the certain time (step S1000; YES), the operation of the centralized controller 5 transitions to step S1001. If the time during which the master signal has not been received has not reached the certain time (step S1000; NO), the centralized controller 5 continues to perform the determination in step S1000.

[0154] (Step S1001) The centralized controller 5 notifies that an abnormality has occurred, and this flow ends.

[0155] 23 is a flowchart showing the operation of the outdoor units 6 (more specifically, the outdoor units 6 other than the original master unit) when the original master unit is restored in the centralized network. As described above, when the original master unit that was disconnected from the air conditioning system 10 due to a failure joins the network of the alternative master unit as a terminal unit after recovery, it sends a recovery notification to each device connected to the centralized network.

[0156] (Step S1100) The outdoor unit 6 determines whether or not a recovery notification has been received. If a recovery notification has been received (step S1100; YES), the operation of the outdoor unit 6 proceeds to step S1101. If a recovery notification has not been received (step S1100; NO), the outdoor unit 6 continues to perform the determination in step S1100.

[0157] (Step S1101) The outdoor unit 6 determines whether or not it is the alternative master unit. If it is the alternative master unit (step S1101; YES), the operation of the outdoor unit 6 proceeds to step S1102. If it is not the alternative master unit (step S1101; NO), this flow ends.

[0158] (Step S1102) The outdoor unit 6 switches its role from the alternative master unit to the terminal unit, and this flow ends.

[0159] <Operation Flow of the Centralized Controller 5 When the Former Master Machine is Restored> FIG. 24 is a flowchart showing the operation of the centralized controller 5 when the former master machine is restored.

[0160] (Step S1200) The centralized controller 5 determines whether or not a recovery notification has been received. If a recovery notification has been received (step S1200; YES), the operation of the centralized controller 5 proceeds to step S1201. If a recovery notification has not been received (step S1200; NO), the centralized controller 5 continues to perform the determination in step S1200.

[0161] (Step S1201) After the network is restored by the original master device, the centralized controller 5 notifies that the master device has been restored, and this flow ends.

[0162] As described above, the air conditioning system 10 in this embodiment achieves the same effects as the air conditioning system 1 in embodiment 1, and can reduce the risk of the entire air conditioning system 10 becoming inoperable when a failure occurs in equipment in the centralized network.

[0163] (Variation 1) The method for determining the fourth standby time is an arbitrary design matter; for example, the larger the MAC address value, the shorter the time may be. The method for setting the representative outdoor unit is also an arbitrary design matter; for example, the representative outdoor unit setting unit 601 may set itself as the main outdoor unit if its own identification ID is the largest among all outdoor units 6 connected to the centralized network. The method for setting priority for the same model is also an arbitrary design matter; for example, the priority setting unit 603 may set it so that the larger the identification ID value, the higher the priority.

[0164] (Variation 2) In the second embodiment, the representative outdoor unit sets the priority of each device connected to the centralized network and transmits a priority list to each device. However, each device connected to the centralized network may set its own priority and that of other devices. In more detail, for example, the representative outdoor unit may transmit to each device a device information list including its own device information and device information collected from each device, and each device may set the priority of each device based on the received device information list using a method similar to that used by the priority setting unit 603. Alternatively, each device may transmit its own device information to each of the other devices, and each device may set the priority of each device based on its own device information and the device information received from the other devices using a method similar to that used by the priority setting unit 603. Furthermore, if there are no overlapping models in the air conditioning system 10, each device may set its own priority based on its own device information and transmit information indicating its set priority to each of the other devices.

[0165] (Variation 3) All or part of the functional units of the outdoor unit 6 (see FIG. 16) may be realized by dedicated hardware. Also, all or part of the functional units of the centralized controller 5 (see FIG. 18) may be realized by dedicated hardware. The dedicated hardware may be, for example, a single circuit, a composite circuit, a programmed processor, an ASIC, an FPGA, or a combination thereof.

[0166] (Modification 4) The technical concepts of the modifications of the first embodiment can also be applied to this embodiment.

[0167] The technical ideas according to the above-described modifications may be realized independently or in appropriate combination.

[0168] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope. Furthermore, the above-described embodiments are intended to explain the present disclosure and do not limit the scope of the present disclosure. In other words, the scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and within the meaning of the disclosure equivalent thereto are considered to be within the scope of the present disclosure.

[0169] The present disclosure can be suitably adopted in a network system including a plurality of devices.

[0170] 1, 10 Air conditioning system, 2, 2a to 2c, 6, 6a to 6g Outdoor unit, 3, 3a to 3c, 7, 7a to 7i Indoor unit, 4, 8, 9, 9a to 9c Transmission line, 5 Centralized controller, 20, 30, 50, 60 Control circuit, 21, 31, 51, 61 Auxiliary storage device, 22, 32, 62 Communication control circuit, 23, 33 Transmission and reception circuit, 52 Communication interface, 53 Operation reception unit, 54 Display, 63 First transmission and reception circuit, 64 Second transmission and reception circuit, 200, 300, 500, 600 Role determination unit, 201 Main / sub setting unit, 202, 602 Equipment information collection unit, 203, 603 Priority setting unit, 204, 604 Recovery notification unit, 205, 301 Operation switching unit, 501 Operation data collection unit, 502 Operation data display unit, 503 equipment control unit, 504 notification unit, 601 representative outdoor unit setting unit

Claims

1. An equipment network system using a master-terminal method, comprising a plurality of devices including a first equipment group consisting of devices that are responsible for controlling the operation of the equipment network system, and a second equipment group consisting of devices that are not included in the first equipment group, wherein one master device is selected from the first equipment group based on unique equipment information corresponding to each of the plurality of devices, and all other devices are selected as terminal devices.

2. The device network system according to claim 1, wherein the device information includes model information that can identify the model of each device.

3. The device network system according to claim 1 or 2, wherein a priority is set for each device based on the device information of each device, and the device with the highest priority among the plurality of devices sets itself as a master device.

4. The equipment network system of claim 3, wherein the master device periodically transmits a master signal to notify the presence of a master device on the network, and if a state in which the master signal is not received from the master device continues for a predetermined period of time or longer, the terminal device with the highest priority among all the terminal devices switches itself to an alternative master device.

5. The device network system according to claim 4, wherein a device belonging to the first device group starts up as a terminal device, and when the device receives the master signal from the alternative master device within a predetermined time, the device joins the network of the alternative master device.

6. The device network system according to claim 4 or 5, wherein the alternative master device switches itself to a terminal device when it receives a recovery notification indicating that the original master device has been recovered from the terminal device.

7. The device network system according to claim 4, wherein the plurality of devices switch their own operation from normal operation to emergency operation when any one of the terminal devices switches to the alternative master device.

8. The device network system according to claim 1, wherein the master device switches itself to a terminal device when it detects a failure in itself.

9. The device network system according to claim 8, wherein the master device transmits a failure occurrence notification to each device, the failure occurrence notification indicating that a failure has occurred.

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