Communication method, refrigeration and air conditioning related system and communication node

Abstract

The invention provides a communication method, a refrigeration and air conditioning related system and a communication node. According to the communication method, data related to state changes of refrigeration and air conditioner related units are communicated among a plurality of communication nodes, and a first communication node generates a message and sends the generated message to a second communication node under the condition that the state changes are detected by the second communication node, the message contains information related to the moment when the second communication node sends the data to the communication node which should send the data.

Description

Technical Field

[0001] The invention relates to a communication method, a refrigeration and air-conditioning related system and a communication node. Background Art

[0002] In a large-scale refrigeration and air conditioning system, for example, multiple outdoor units are connected to a centralized control device, and multiple indoor units are connected to each outdoor unit to construct a network for communication (for example, see Patent Document 1). Various data are sent and received between multiple devices including the centralized control device, outdoor units, and indoor units, thereby realizing centralized control of each device, cooperative operation, etc. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2008-20092 Summary of the invention Technical problem to be solved by the invention

[0004] An object of the present disclosure is to provide a communication method, a refrigeration and air-conditioning related system, and a communication node capable of suppressing an increase in a processing load of a specific device. Technical solutions adopted to solve technical problems

[0005] A communication method according to one aspect of the present disclosure enables data related to state changes of refrigeration and air conditioning related units to be communicated between multiple communication nodes, wherein, when a second communication node detects the state change, a first communication node generates a message and sends the generated message to the second communication node, wherein the message includes information related to the moment when the second communication node sends the data to the communication node to which the data should be sent.

[0006] In one aspect of the communication method of the present disclosure, it is preferred that, when the second communication node detects the change, the second communication node delays the transmission of the data based on the information related to the time contained in the received message.

[0007] In the communication method according to one aspect of the present disclosure, it is preferred that the time is determined as the earliest time after the state change is detected among a plurality of times inherently determined by the second communication node.

[0008] In the communication method according to one aspect of the present disclosure, it is preferable that the timing is specified based on an elapsed time from detection of the state change.

[0009] In the communication method according to one aspect of the present disclosure, it is preferable that the time is defined based on an elapsed time from a reference time synchronized between the second communication nodes.

[0010] In the communication method according to one aspect of the present disclosure, it is preferable that the timing is defined based on the number and order of communication nodes to which the data should be transmitted.

[0011] In the communication method according to one aspect of the present disclosure, preferably, the first communication node is an outdoor unit, and the second communication node is an indoor unit.

[0012] Preferably, in one aspect of the communication method of the present disclosure, the first communication node further includes a centralized control device.

[0013] In the communication method according to one aspect of the present disclosure, preferably, the first communication node further includes a service inspector.

[0014] In the communication method according to one aspect of the present disclosure, it is preferred that the message has a format specified by CoAP (Constrained Application Protocol), and the information related to the time is described in a payload included in the message.

[0015] In a refrigeration and air-conditioning related system of one aspect of the present disclosure, data related to state changes of refrigeration and air-conditioning related units are communicated between multiple communication nodes, and a first communication node includes a control unit and a communication unit. When a second communication node detects the state change, the control unit generates a message, and the message includes information related to the moment when the second communication node sends the data to the communication node to which the data should be sent, and the communication unit sends the message generated by the control unit to the second communication node.

[0016] A communication node in one aspect of the present disclosure is a communication node in a refrigeration and air-conditioning related system, including a control unit and a communication unit. The control unit generates a message when other communication nodes detect a state change of a refrigeration and air-conditioning related unit. The message includes information related to the moment when the other communication nodes send data to the communication node to which the data should be sent. The communication unit sends the message generated by the control unit to the other communication nodes. Effects of the Invention

[0017] According to the present disclosure, it is possible to suppress an increase in the processing load in a specific device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram showing a configuration example of a refrigeration and air-conditioning related system according to an embodiment. Figure 2 This is a block diagram for explaining a configuration example of an outdoor unit. Figure 3 This is a block diagram for explaining a configuration example of an indoor unit. Figure 4 This is a block diagram for explaining a configuration example of a centralized control device. Figure 5 This is a block diagram showing a configuration example of a relay device. Figure 6 This is a conceptual diagram showing the format of messages (telegrams) sent and received between devices. Figure 7 This is a flowchart for explaining a communication procedure in communication related to refrigerant control. Figure 8 This is a flowchart for explaining a communication procedure in communication related to refrigerant control. Fig. 9 This is a flowchart for explaining the communication procedure in the communication related to the centralized control. Fig.10 This is a flowchart for explaining the communication procedure in the communication related to the centralized control. Fig.11 This is an explanatory diagram for explaining an example of setting the transmission timing. Fig.12 This is a sequence diagram for explaining the communication procedure in the second embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, the refrigeration and air conditioning related system of the embodiment will be described in detail based on the drawings. In addition, the present technology is not limited to these examples, but is intended to include all changes within the meaning and scope of the claims and equivalents to the claims.

[0020] (Implementation Method 1) Figure 1 It is a schematic diagram showing a structural example of a refrigeration and air conditioning related system of an embodiment. The refrigeration and air conditioning related system 1 of the embodiment is a system for communicating information related to refrigeration and air conditioning related units between multiple communication nodes. The communication nodes constituting the refrigeration and air conditioning related system 1 include refrigeration and air conditioning related equipment such as a centralized control device 10, an outdoor unit 30, an indoor unit 50, and a relay device 70. The information sent and received between the communication nodes is information related to the refrigeration and air conditioning related units, including information related to refrigerant control, information related to centralized monitoring operations, and the like. Here, the information related to the refrigeration and air conditioning related units may be information about the device itself, or information related to elements constituting a part of the refrigeration and air conditioning related equipment.

[0021] The communication nodes are not limited to the above-mentioned devices, and may also include various refrigeration and air conditioning related devices such as a service checker, a remote controller, a ventilation device, a communication device, and a control device. In the following description, the refrigeration and air conditioning related devices connected to the refrigeration and air conditioning related system 1 as communication nodes are also referred to as devices.

[0022] exist Figure 1In the refrigeration and air-conditioning related system 1 shown, a centralized control device 10 is connected to a plurality of outdoor units 30 via transmission lines. In the present embodiment, a plurality of devices are connected in a daisy chain manner. That is, the first outdoor unit 30 is connected to the centralized control device 1 via a first transmission line, the second outdoor unit 30 is connected to the first outdoor unit 30 via a second transmission line, and the third outdoor unit 30 is connected to the second outdoor unit 30 via a third transmission line. Here, the plurality of transmission lines connecting the centralized control device 10 to the plurality of outdoor units 30 are electrically conductive. Therefore, for example, a signal sent by the centralized control device 10 can be received by all the outdoor units 30 connected in a daisy chain manner, and a signal sent by any outdoor unit 30 can be received by the centralized control device 10 and all the remaining outdoor units 30.

[0023] In addition, in the refrigeration and air conditioning related system 1, a plurality of indoor units 50 are connected to each outdoor unit 30 in a daisy chain manner via transmission lines. That is, the first indoor unit 50 is connected to one outdoor unit 30 via a first transmission line, and the second indoor unit 50 is connected to the first indoor unit 50 via a second transmission line. The plurality of transmission lines connecting the outdoor unit 30 and the plurality of indoor units 50 are electrically connected, and a signal transmitted by any device can be received by all devices connected in the daisy chain manner.

[0024] Each outdoor unit 30 is connected to a transmission line for communicating with the central control device 10 and the remaining outdoor units 30 and a transmission line for communicating with the indoor unit 50. In the present embodiment, the two transmission lines are electrically connected inside the outdoor unit 30. Therefore, for example, the central control device 10 can communicate with the indoor unit 50 via the outdoor unit 30. In addition, the indoor unit 50 connected to the first outdoor unit 30 can communicate with the other indoor units 50 connected to the second outdoor unit 30 via the first outdoor unit 30 and the second outdoor unit 30. In addition, the transmission line for communicating with the central control device 10 and the remaining outdoor units 30 and the transmission line for communicating with the indoor unit 50 can also be electrically isolated inside the outdoor unit 30.

[0025] In addition, the refrigeration and air conditioning system 1 may also include a relay device 70. For example, when the distance between two devices that should be directly connected via a transmission line is long and the length of the transmission line exceeds a predetermined length, a relay device 70 is provided between the devices. Figure 1 In the refrigeration and air conditioning system 1 illustrated in FIG. 1 , two relay devices 70 are provided to be connected between two indoor units 50, 50. That is, the relay device 70 is connected to the first indoor unit 50 via a first transmission line, and the second indoor unit 50 is connected to the relay device 70 via a second transmission line.

[0026] The relay device 70 may be installed at any position of the refrigeration and air conditioning system 1. For example, the relay device 70 may be installed between the centralized control device 10 and the outdoor unit 30, between two outdoor units 30, 30, and between the outdoor unit 30 and the indoor unit 50. In addition, the relay device 70 may be installed between various devices other than the centralized device 10, the outdoor unit 30, and the indoor unit 50. In addition, the relay device 70 is not essential, and the refrigeration and air conditioning system 1 may be constructed without the relay device 70.

[0027] Figure 2 3 is a block diagram for explaining a configuration example of the outdoor unit 30. The outdoor unit 30 includes, for example, a control unit 31, a storage unit 32, a communication unit 33, and connection terminals 34 to 36. The control unit 31 is composed of, for example, a microcomputer, a CPU (central processing unit), or other arithmetic processing devices. The control unit 31 can perform various processes by reading and executing programs stored in the storage unit 32. The control unit 31 performs various control processes such as control of the operation of each part of the outdoor unit 30 and control of communication with the centralized control device 10, other outdoor units 30, and the indoor unit 50. The control unit 31 has a built-in clock that outputs time information, a timer for measuring elapsed time, and the like.

[0028] The storage unit 32 includes, for example, nonvolatile memories such as flash memory and EEPROM (Electrically Erasable Programmable Read Only Memory) and volatile memories such as DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory). The storage unit 32 stores various programs executed by the control unit 31 and various data required for the control processing of the control unit 31. Various programs are stored in the nonvolatile memory. On the other hand, various data may be stored only in the volatile memory, or may be copied and stored in the nonvolatile memory after being stored in the volatile memory.

[0029] The communication unit 33 is composed of, for example, a transceiver IC (integrated circuit). The communication unit 33 communicates with the centralized control device 10, other outdoor units 30, and the indoor unit 50 via a transmission line connected to a plurality of connection terminals 34 to 36 included in the outdoor unit 30. The communication unit 33 modulates the data to be sent and received, for example, by OFDM (Orthogonal Frequency Division Multiplexing). Specifically, the communication unit 33 uses a frequency band of 2 to 28 MHz for multi-carrier transmission. The communication unit 33 outputs a signal modulated from the transmission data provided by the control unit 31 to the transmission line, thereby transmitting the data, and provides the data obtained by acquiring the signal on the transmission line and demodulating it as received data to the control unit 31.

[0030] The communication unit 33 may also have a multi-hop function. The multi-hop function refers to a function in which, when the second device receives a signal sent by the first device, the second device outputs the same signal as the received signal to the transmission line. By each device outputting the same signal as the received signal, signal attenuation can be suppressed and the transmission distance of the signal can be extended.

[0031] The three connection terminals 34 to 36 are constructed using electronic components such as connectors or sockets, and are connected to the transmission line for communication in a detachable manner. In the outdoor unit 30 of the present embodiment, the three connection terminals 34 to 36 are electrically connected, for example, via a wiring pattern on a circuit substrate, and are electrically connected to the communication unit 33. Therefore, a signal input from any connection terminal 34 to 36 is output from the other connection terminals 34 to 36 and input to the communication unit 33. In addition, the signal output from the communication unit 33 is output from the connection terminals 34 to 36. In addition, in the present embodiment, the three connection terminals 34 to 36 are directly connected via a wiring pattern, etc., but, for example, a filter circuit or the like may be provided between the connection terminals 34 to 36. The number of connection terminals included in the outdoor unit 30 may also be less than two or more than four.

[0032] Figure 3 1 is a block diagram for explaining a configuration example of the indoor unit 50. The indoor unit 50 includes a control unit 51, a storage unit 52, a communication unit 53, and two connection terminals 54 and 55. The control unit 51 is composed of a microcomputer, a CPU, or other arithmetic processing devices. The control unit 51 performs various control processes such as control of the operation of each part of the indoor unit 50 and control of communication with the centralized control device 10, the outdoor unit 30, and other indoor units 50. The control unit 51 has a built-in clock that outputs time information, a timer for measuring elapsed time, and the like.

[0033] The storage unit 52 includes, for example, nonvolatile memories such as flash memory and EEPROM, and volatile memories such as DRAM and SRAM. The storage unit 52 stores various programs executed by the control unit 51 and various data required for the control processing of the control unit 51. Various programs are stored in the nonvolatile memory. On the other hand, various data may be stored only in the volatile memory, or may be copied and stored in the nonvolatile memory after being stored in the volatile memory.

[0034] The communication unit 53 is composed of, for example, a transceiver IC. The communication unit 53 has the same function as the communication unit 33 of the outdoor unit 30, and can use the same or the same type of IC as the IC used for the communication unit 33 of the outdoor unit 30. The communication unit 53 has a modulation function and a multi-hop function realized by the OFDM method, and communicates with the centralized control device 10, the outdoor unit 30, and other indoor units 50 via a transmission line connected to the connection terminals 54 and 55 included in the indoor unit 50. The communication unit 53 outputs a signal modulated from the transmission data provided by the control unit 51 to the transmission line, thereby transmitting the data, and provides the data obtained by acquiring the signal on the transmission line and demodulating it as received data to the control unit 51.

[0035] The two connection terminals 54 and 55 are formed using electronic components such as connectors or sockets, and are detachably connected to a transmission line for communication. The connection terminals 54 and 55 are electrically connected, for example, via a wiring pattern on a circuit board, and are electrically connected to the communication unit 53. The number of connection terminals included in the indoor unit 50 may be one or more than three.

[0036] Figure 4 This is a block diagram for explaining a configuration example of the centralized control device 10. The centralized control device 10 includes, for example, a control unit 11, a storage unit 12, a communication unit 13, a display unit 14, an operation unit 15, and a connection terminal 16. The control unit 11 is composed of a calculation processing device such as a CPU. The control unit 11 performs various control processes such as control of the operation of each part of the centralized control device 10 and control of communication with the outdoor unit 30 and other indoor units 50. The control unit 11 has a built-in clock that outputs time information, a timer for measuring elapsed time, and the like.

[0037] The storage unit 12 includes, for example, a nonvolatile memory such as a flash memory, an EEPROM (or a magnetic storage device such as a hard disk) and a volatile memory such as a DRAM, an SRAM, etc. The storage unit 12 stores various programs executed by the control unit 11 and various data required for the control processing of the control unit 11. Various programs are stored in the nonvolatile memory. On the other hand, various data may be stored only in the volatile memory, or may be copied and stored in the nonvolatile memory after being stored in the volatile memory.

[0038] The communication unit 13 is composed of, for example, a transceiver IC. The communication unit 13 has the same functions as the communication unit 33 of the outdoor unit 30 and the communication unit 53 of the indoor unit 50, and can use the same or the same type of IC as the IC used for the communication unit 33 of the outdoor unit 30 and the communication unit 53 of the indoor unit 50. The communication unit 13 has a modulation function and a multi-hop function realized by the OFDM method, and communicates with the outdoor unit 30 and the indoor unit 50 via a transmission line connected to the connection terminal 16 included in the centralized control device 10. The communication unit 13 outputs a signal obtained by modulating the transmission data provided by the control unit 11 to the transmission line, thereby transmitting the data, and provides the data obtained by acquiring the signal on the transmission line and demodulating it as received data to the control unit 11.

[0039] The display unit 14 is composed of a liquid crystal display and the like, and displays various images and characters and the like in accordance with the control of the control unit 11. The operation unit 15 receives the user's operation and notifies the control unit 11 of the received operation. For example, the operation unit 15 receives the user's operation through an input device such as a mechanical key or a touch panel provided on the surface of the display unit 14. In addition, for example, the operation unit 15 may also be an input device such as a mouse and a keyboard, and these input devices may also be configured to be removable relative to the centralized control device 10. The connection terminal 16 is configured using electronic components such as a connector or a socket, and is connected to a transmission line used for communication in a detachable manner. The connection terminal 16 is electrically connected to the communication unit 13, for example, via a wiring pattern on a circuit substrate. The number of connection terminals included in the centralized control device 10 may also be two or more.

[0040] Figure 5 : is a block diagram showing a structural example of a relay device 70. The relay device 70 of the present embodiment is configured to include a communication unit 71 and two connection terminals 72, 73, etc. The communication unit 71 is configured using, for example, a transceiver IC, etc. The communication unit 71 has the same function as the communication unit 33 of the outdoor unit 30, the communication unit 53 of the indoor unit 50, and the communication unit 13 of the centralized control device 10, and it is possible to use the same or the same type of IC as the IC used for these communication units. The communication unit 71 has a modulation function and a multi-hop function implemented by the OFDM method, and communicates between it and the centralized control device 10, the outdoor unit 30, and the indoor unit 50, etc. via a transmission line connected to the connection terminals 72, 73 included in the relay device 70. In addition, the communication unit 71 of the relay device 70 only needs to include at least the multi-hop function, and it may not include the modulation function implemented by the OFDM method.

[0041] The two connection terminals 72 and 73 are formed by using electronic components such as connectors or sockets, and are connected to the transmission line for communication in a detachable manner. The connection terminals 72 and 73 are electrically connected, for example, via a wiring pattern on a circuit substrate, and are electrically connected to the communication unit 71. The number of connection terminals included in the relay device 70 may be one or more than three.

[0042] In the refrigeration and air conditioning related system 1, multiple devices such as a centralized control device 10, an outdoor unit 30, an indoor unit 50, and a relay device 70 are connected in a daisy chain manner via a transmission line, and multi-carrier communication is implemented by OFDM modulation. The multiple transmission lines connecting the multiple devices are electrically connected, and the signal sent by one device can be received by all other devices. In the case where each device has a multi-hop function of outputting the same signal as the received signal to the transmission line, the strength of the signal that is attenuated corresponding to the transmission distance from the transmission source is increased, thereby extending the transmission distance of the signal.

[0043] As a communication method that can use OFDM modulation and multi-hop functions, there is, for example, a communication method of HD-PLC (High Definition Power Line Communication). The communication unit of each device can be composed of, for example, a transceiver IC that adopts the communication method of HD-PLC. In addition, the communication method of HD-PLC is a communication method that communicates via a power line, but in the refrigeration and air conditioning related system 1 of the embodiment, each device communicates via a transmission line set separately from the power line, rather than communicating via the power line.

[0044] Figure 6 This is a conceptual diagram showing the format of messages (telegrams) sent and received between devices. The communication protocol used in the refrigeration and air conditioning related system 1 of the implementation method is as follows. The physical / data link layer uses HD-PLC and Ethernet (registered trademark). The network layer uses IPv6. The transport layer uses UDP (User Datagram Protocol). The application layer uses CoAP (Constrained Application Protocol).

[0045] The messages sent and received between devices are composed of headers corresponding to each layer (i.e., HD-PLC header, IPv6 header, UDP header, CoAP header) and data describing the content to be sent.

[0046] IPv6 is ideal for the refrigeration and air-conditioning related system 1. Various devices connected so as to be accessible to each other can be identified and communicated with each other through IP addresses of a common standard.

[0047] UDP is ideal for the refrigeration and air-conditioning system 1. Even when the outdoor unit 30 is connected to a plurality of indoor units 50, no connection is established like TPC, and therefore, no burden is placed on the memory of the outdoor unit 30.

[0048] CoAP is ideal for refrigeration and air conditioning systems 1. Since binary messages are used, lighter communication is possible than HTTP. A correspondence is established between requests and responses, and data can be resent in the event of a request failure. In addition, by specifying the method described later, data related to control, operating status, etc. can be obtained and updated between devices.

[0049] In an implementation, when information is sent from one device (first communication node) to another device (second communication node), the first communication node as the sending source generates a message and sends the generated message to the second node as the destination, wherein the message includes a code representing the attributes of the information and a type indicating whether a response specified according to the attributes is required.

[0050] The code representing the attribute of information represents the operation on the data, also called a method. In the implementation, "GET" representing the operation of obtaining the other party's data, "SET" representing the operation of updating the other party's data, "INF" representing the operation of notifying one's own data, etc. can be used as methods. In order to obtain data, a response is required, so for methods such as "GET", a response is specified as the type. On the other hand, no response is required for the operation of updating the value or the operation of notifying information, so no response is specified as the type for methods such as "SET" or "INF". In addition, the method is not limited to the above methods, and may also include "DELETE" representing the operation of deleting the other party's data, etc.

[0051] In addition, it is also possible to define whether retransmission is required in the message sent and received by the refrigeration and air conditioning related system 1. For example, even if a message sent regularly does not reach the destination for some reason, it only needs to be sent at the next sending time, so retransmission is not required. On the other hand, when a user operates through the operation unit 15 of the centralized control device 10, a remote controller, etc., the operation result needs to be reflected in a relatively short time (several seconds), requiring high reliability, so retransmission is required.

[0052] The above methods or the need for a response and the need for retransmission can be described in the CoAP header. The methods of "GET", "SET", and "INF" can be respectively adapted from "GET", "POST", and "PUT" defined in CoAP, and can be specified in the CoAP header.

[0053] In addition, the need for a response can be determined by using the "No Server Response" option of CoAP. That is, if a response is required, "0" is specified in the CoAP header, and if a response is not required, "0x32" is specified in the CoAP header.

[0054] In addition, the need for retransmission is described in the type area of ​​the CoAP header. That is, if retransmission is required, specify "CON (= message that needs to be confirmed)", and if retransmission is not required, specify "NON (= message that does not need to be confirmed)". The device that receives the message confirms the type area of ​​the CoAP header, and if it is CON, it replies with an ACK message. If the sending side does not receive an ACK message within a certain period of time, the message is retransmitted.

[0055] Hereinafter, an application example of the refrigeration and air-conditioning related system 1 will be described. The communication in the refrigeration and air conditioning system 1 generally includes communication related to refrigerant control and communication related to centralized control. The communication related to refrigerant control is mainly communication between the outdoor unit 30 and the indoor unit 50 connected by the refrigerant piping, and is used to appropriately control the equipment to perform air conditioning. On the other hand, the communication related to centralized control is communication for centralized monitoring and operation of the indoor unit 30 and the indoor unit 50 from the centralized control device 10.

[0056] Figure 7 and Figure 8 This is a flowchart for explaining the communication steps in the communication related to the refrigerant control. In the communication related to the refrigerant control, one outdoor unit 30 in the refrigerant system becomes a master unit and communicates with a plurality of indoor units 50 (slave units) or the remaining outdoor units 30 (master units). Figure 7 In the flowchart of FIG. 1 , for simplicity, the communication procedure between an outdoor unit 30 as a master unit and an indoor unit 50 as a slave unit is described. The outdoor unit 30 and the indoor unit 50 each store data of the communication object internally and update the data through communication. The outdoor unit 30 and the indoor unit 50 determine the operation of the unit by referring to the data stored internally.

[0057] The control unit 31 of the outdoor unit 30 determines whether to acquire data from the indoor unit 50 (step S101). The control unit 31 may determine whether to acquire data from the indoor unit 50 by referring to the output of the built-in clock or the built-in timer and determining whether the current time point matches the time set as the acquisition time. The time to acquire data may be, for example, a regular time.

[0058] When it is determined that the data of the indoor unit 50 is to be acquired (S101: Yes), the control unit 31 generates a message including a CoAP header that specifies "GET" as the method, "Required" as the need for a response, and "NON" as the need for retransmission (step S102). The control unit 31 transmits the generated message to the indoor unit 50 of the destination through the communication unit 33 (step S103).

[0059] When receiving the message sent from the outdoor unit 30, the control unit 51 of the indoor unit 50 checks the CoAP header of the received message. In the CoAP header, when the method is specified as "GET", the need for a response is "necessary", so the control unit 51 generates a message including the data requested by the outdoor unit 30 and replies to the outdoor unit 30 (step S104).

[0060] When receiving the reply message from the indoor unit 50, the control unit 31 of the outdoor unit 30 stores the data included in the received message in the storage unit 32 (step S105). Here, the received message may be stored only in the volatile memory included in the storage unit 32, or may be copied and stored in the non-volatile memory after being stored in the volatile memory.

[0061] Next, the control unit 31 of the outdoor unit 30 determines whether to update the data of the indoor unit 50 (step S106). The control unit 31 can determine whether to update the data of the indoor unit 50 by referring to the output of the built-in clock or the built-in timer and determining whether the current time point matches the time set as the update time. The time to update the data may be, for example, a regular time.

[0062] When it is determined that the data of the indoor unit 50 is to be updated (S106: Yes), the control unit 31 generates a message including a CoAP header that specifies "SET" as the method, "Not required" as the need for a response, and "NON" as the need for retransmission (step S107). The control unit 31 transmits the generated message to the indoor unit 50 of the destination through the communication unit 33 (step S108).

[0063] When the control unit 51 of the indoor unit 50 receives the message sent from the outdoor unit 30, it checks the CoAP header of the received message. In the CoAP header, when the method is designated as "SET", the need for a response is "not required", so the control unit 51 does not reply to the received message, but updates the data stored in the storage unit 52 (step S109). The data to be updated can be stored in a volatile memory included in the storage unit 52, or in a non-volatile memory.

[0064] Next, the control unit 31 of the outdoor unit 30 determines whether to notify the indoor unit 50 of the data of the unit (step S110). The control unit 31 only needs to refer to the output of the built-in clock or the built-in timer and determine whether the current time point matches the time set as the notification time, thereby determining whether to notify the indoor unit 50. The time to notify the indoor unit 50 may specify a regular time, for example. In addition, the time to notify the indoor unit 50 may also specify a time when an internal state has changed. Here, the change in the internal state means a change in the value of various sensors or actuators included in the device or a change in the control state.

[0065] When it is determined that the data is to be notified to the indoor unit 50 (S110: Yes), the control unit 31 generates a message including a CoAP header that specifies "INF" as the method, "not required" as the need for a response, and "NON" as the need for retransmission (step S111). The control unit 31 transmits the generated message to the indoor unit 50 of the destination through the communication unit 33 (step S112).

[0066] When the control unit 51 of the indoor unit 50 receives the message sent from the outdoor unit 30, it checks the CoAP header of the received message. In the CoAP header, when the method is specified as "INF", the need for a response is "not required", so the control unit 51 does not reply to the received message, but stores the notified data in the storage unit 52 (step S113). Here, the received message can be stored only in the volatile memory included in the storage unit 52, or it can be copied and stored in the non-volatile memory after being stored in the volatile memory.

[0067] The indoor unit 50 basically only receives communication from the outdoor unit 30 , but may notify the outdoor unit 30 of data when a remote controller is operated and an internal state changes.

[0068] The control unit 51 of the indoor unit 50 determines whether to notify the data of the indoor unit 50 (step S114). When it is determined that the internal state of the indoor unit has changed and notification is made (S114: Yes), the control unit 51 generates a message including a CoAP header that specifies "INF" as the method, "not required" as the need for response, and "CON" as the need for retransmission (step S115). The control unit 51 transmits the generated message to the destination outdoor unit 30 through the communication unit 53 (step S116).

[0069] When receiving the message sent from the indoor unit 50, the control unit 31 of the outdoor unit 30 confirms the CoAP header of the received message. In the CoAP header, when the method is specified as "INF", the need for a response is "not needed", but the need for retransmission is "CON", so the control unit 31 replies with an ACK message through the communication unit 31 (step S117). In addition, the control unit 31 stores the data contained in the message received through the indoor unit 50 in the storage unit 32 (step S118). Here, the received message can be stored only in the volatile memory included in the storage unit 32, or it can be copied and stored in the non-volatile memory after being stored in the volatile memory.

[0070] If the control unit 51 of the indoor unit 50 does not receive an ACK message within a certain period of time after transmitting the message in step S115, the control unit 51 retransmits the message. When retransmitting the message, the control unit 51 only needs to update the content of the data to be transmitted to the latest content and retransmit it.

[0071] exist Figure 7 and Figure 8 In the flowchart shown, the judgment is performed in the order of whether to obtain data, whether to update the other party's data, and whether to notify the other party of the data, but the above judgment order is only a convenient order and can be performed in any order.

[0072] Fig. 9 and Fig.10 This is a flowchart for explaining the communication steps in the communication related to the centralized control. In the communication related to the centralized control, the centralized control device 10 performs communication for centralized monitoring and operation of each outdoor unit 30 and each indoor unit 50. The centralized control device 10 displays the status of each outdoor unit 30 and each indoor unit 50 on the display unit 14 through icons, and performs air conditioning control or scheduling operation through icon operation via the operation unit 15. Fig. 9 and Fig.10 In the flowchart shown, for simplicity, the communication procedure between the central control device 10 and the indoor unit 50 is described.

[0073] The control unit 11 of the centralized control device 10 determines whether to acquire the data of the indoor unit 50 (step S121). The control unit 11 only needs to refer to the output of the built-in clock or the built-in timer and determine whether the current time point matches the time set as the acquisition time to determine whether to acquire the data of the indoor unit 50. The time to acquire data may specify a regular time, for example.

[0074] When it is determined that the data of the indoor unit 50 is to be acquired (S121: Yes), the control unit 11 generates a message including a CoAP header that specifies "GET" as the method, "Required" as the need for a response, and "NON" as the need for retransmission (step S122). The control unit 11 transmits the generated message to the indoor unit 50 of the destination through the communication unit 13 (step S123).

[0075] The control unit 51 of the indoor unit 50 confirms the CoAP header of the received message when receiving the message sent from the centralized control device 10. In the CoAP header, when the method is specified as "GET", the need for a response is "necessary", so the control unit 51 generates a message including the data requested by the centralized control device 10 and replies to the centralized control device 10 (step S124).

[0076] When receiving the reply message from the indoor unit 50, the control unit 11 of the central control device 10 stores the data contained in the received message in the storage unit 12 (step S125). Here, the received message may be stored only in the volatile memory included in the storage unit 12, or may be copied and stored in the non-volatile memory after being stored in the volatile memory.

[0077] Next, the control unit 11 of the centralized control device 10 determines whether to update the data of the indoor unit 50 (step S126). The control unit 11 determines to update the data of the indoor unit 50 when a state change occurs due to, for example, an icon operation or a schedule via the operation unit 15.

[0078] When it is determined that the data of the indoor unit 50 is to be updated (S126: Yes), the control unit 11 generates a message including a CoAP header that specifies "SET" as the method, "not required" as the need for a response, and "CON" as the need for retransmission (step S127). The control unit 11 transmits the generated message to the indoor unit 50 of the destination through the communication unit 13 (step S128).

[0079] When receiving the message sent from the centralized control device 10, the control unit 51 of the indoor unit 50 confirms the CoAP header of the received message. In the CoAP header, when the method is specified as "SET", the need for a response is "not required", but the need for retransmission is "CON", so the control unit 51 replies with an ACK message through the communication unit 53 (step S129). In addition, the control unit 51 updates the data maintained in the storage unit 52 according to the "SET" request (step S130). The data to be updated can be maintained in a volatile memory included in the storage unit 52, or in a non-volatile memory.

[0080] If the control unit 11 of the centralized control device 10 does not receive an ACK message within a certain period of time after sending the message in step S128, the control unit 11 retransmits the message. When retransmitting the message, the control unit 11 only needs to update the content of the data to be sent to the latest content and retransmit it.

[0081] The indoor unit 50 basically only receives communications from the central control device 10 , but may notify data to the central control device 10 when a remote controller is operated and an internal state changes.

[0082] The control unit 51 of the indoor unit 50 determines whether to notify the centralized control device 10 of the data of the unit (step S131). When it is determined that the internal state of the unit has changed and notification is made (S131: Yes), the control unit 51 generates a message including a CoAP header that specifies "INF" as the method, "not required" as the need for response, and "CON" as the need for retransmission (step S132). The control unit 51 transmits the generated message to the centralized control device 10 via the communication unit 53 (step S133).

[0083] When receiving a message sent from the indoor unit 50, the control unit 11 of the centralized control device 10 confirms the CoAP header of the received message. In the CoAP header, when the method is specified as "INF", the need for a response is "not needed", but the need for retransmission is "CON", so the control unit 11 replies with an ACK message through the communication unit 13 (step S134). In addition, the control unit 11 stores the data contained in the message received through the indoor unit 50 in the storage unit 32 (step S135). Here, the received message can be stored only in the volatile memory included in the storage unit 32, or it can be copied and stored in the non-volatile memory after being stored in the volatile memory.

[0084] If the control unit 51 of the indoor unit 50 does not receive an ACK message within a certain period of time after transmitting the message in step S133, the control unit 51 retransmits the message. When retransmitting the message, the control unit 51 only needs to update the content of the data to be transmitted to the latest content and retransmit it.

[0085] exist Fig. 9 and Fig.10 In the flowchart shown, the judgment is performed in the order of whether to obtain data, whether to update the other party's data, and whether to notify the other party of the data, but the above judgment order is only a convenient order and can be performed in any order.

[0086] Generally speaking, the relationship between request and response is specified in communication, but in this embodiment, when a response is not required, the need for a response is specified as "not required", and no response is returned to the received request. In addition, in order to ensure reliability, the telegram is sometimes resent, but in this embodiment, the telegram is resent in the minimum required situation. By adopting the above structure, in this embodiment, the communication band can be ensured and the load of each device can be reduced.

[0087] (Implementation Method 2) In the second embodiment, a configuration will be described in which a message is transmitted from the outdoor unit 30 to the indoor unit 50 to thereby specify the transmission timing of data when the indoor unit 50 detects a state change.

[0088] In the second embodiment, when data related to the state change of the refrigeration and air conditioning related unit is sent from the indoor unit 50 to the outdoor unit 30, time division is performed so that the load is not concentrated on the outdoor unit 30. Here, the state change of the refrigeration and air conditioning related unit means, for example, a change in the value of various sensors or actuators included in the indoor unit 50.

[0089] Specifically, when the indoor unit 50 (second communication node) detects a state change, the outdoor unit 30 (first communication node) generates a message containing information about the time at which the indoor unit 50 should send data, and sends the generated message to the indoor unit 50. Information about the time of sending is described in the payload of the data after CoAP, for example. The indoor unit 50 sends data according to the time described in the message, thereby avoiding the concentration of load on the outdoor unit 30.

[0090] Fig.11 The diagram is an explanatory diagram for explaining an example of setting the transmission time. The transmission time is defined based on the elapsed time from the reference time synchronized among the plurality of indoor units 50, and is determined as a time unique to each of the plurality of indoor units 50. Fig.11 In the example of , the transmission times of three indoor units 50, 50, and 50 are shown.

[0091] Time T0 represents a reference time synchronized among the three indoor units 50, 50, 50. Time T11, T12, T13, ... represent transmission times determined for the first indoor unit 50, time T21, T22, T23, ... represent transmission times determined for the second indoor unit 50, and time T31, T32, T33, ... represent transmission times determined for the third indoor unit 50.

[0092] exist Fig.11In the example of , the transmission time cycle is common to each indoor unit 50. That is, T12-T11=(T13-T12=T14-T13=...)=T22-T21(=T23-T22=T24-T23=...)=T32-T31(=T33-T32=T34-T33=...). Fig.11 In the example of , the time interval between the reference time and the initial transmission time is set to a value specific to each indoor unit 50. That is, T11≠T21≠T31 is set. By setting the transmission time of each indoor unit 50 as described above, the transmission time of each indoor unit 50 can be staggered.

[0093] Each indoor unit 50 calculates the time at which it can transmit information related to the state change based on the transmission time determined by the unit. Fig.11 At the time TA shown in , a state change is detected in each indoor unit 50. In this case, in the first indoor unit 50, among the multiple transmission times T11, T12, ..., the earliest time after the state change is detected is T14, so the transmission of data is delayed until this time. That is, the delay time of the first indoor unit 50 is T14-TA. In addition, in the second indoor unit 50, among the multiple transmission times T21, T22, ..., the earliest time after the state change is detected is T23, so the transmission of data is delayed until this time. That is, the delay time of the second indoor unit 50 is T23-TA. Similarly, in the third indoor unit 50, among the multiple transmission times T31, T32, ..., the earliest time after the state change is detected is T33, so the transmission of data is delayed until this time. That is, the delay time of the third indoor unit 50 is T33-TA.

[0094] exist Fig.11 In the example of FIG. 1 , the period of the transmission time set in each indoor unit 50 is fixed, but as long as the transmission times in two or more indoor units 50 do not overlap, different periods may be set between the indoor units 50. The transmission time of the indoor unit 50 can be appropriately set according to the number of indoor units 50 to which data should be transmitted, the priority order of the indoor units 50 to which data should be transmitted, and the like.

[0095] In addition, the transmission time of the indoor unit 50 may also be set based on the elapsed time from the time when each indoor unit 50 detects the state change. For example, when each indoor unit 50 detects the state change at time TA, the first indoor unit 50 may set the time when time T1 has passed from time TA as the transmission time, the second indoor unit 50 may set the time when T2 (≠T1) has passed from time TA as the transmission time, and the third indoor unit 50 may set the time when T3 (≠T1≠T2) has passed from time TA as the transmission time.

[0096] Fig.12 This is a timing diagram for explaining the communication steps in the second implementation mode. The control unit 31 of the outdoor unit 30 generates a message containing information related to the sending time when each indoor unit 50 should send data, and sends the generated message to each indoor unit 50 through the communication unit 33, thereby notifying each outdoor unit 30 of the sending time (step S201). In step S201, since it is a notification from the outdoor unit 30 to the indoor unit 50, the control unit 31 generates a message containing a CoAP header and recording the sending time inherent to each indoor unit 50 in the payload of the data, and sends it to each indoor unit 50, wherein in the CoAP header, the method is specified as "INF", the need for a response is specified as "not required", and the need for retransmission is specified as "NON".

[0097] When receiving a message sent from the outdoor unit 30, the control unit 51 of each indoor unit 50 checks the CoAP header of the received message. In the CoAP header, when the method is specified as "INF", the need for a response is "not required", so the control unit 51 does not reply to the received message, but stores the data including the sending time in the storage unit 52 (steps S202 to S204). Here, the received message can be stored only in the volatile memory included in the storage unit 52, or it can be copied and stored in the non-volatile memory after being stored in the volatile memory.

[0098] The control unit 51 of each indoor unit 50 monitors the status of the sensor or actuator included therein. When the control unit 51 detects a change in the status of the unit (steps S205 to S207), it calculates the time when the unit can send data based on the sending time stored in the storage unit 52 (steps S208 to S210). Here, the sending time of the unit can be stored in a volatile memory included in the storage unit 52, or in a non-volatile memory.

[0099] Each indoor unit 50 determines whether the current time point is a time point at which transmission can be performed, and if it is determined that it is a time point at which transmission can be performed, generates a message including information related to the state change, and sends the generated message to the outdoor unit 30 through the communication unit 53, thereby notifying the outdoor unit 30 of the state change (steps S211 to S213). In steps S211 to S213, since the notification of the accompanying state change is from the indoor unit 50 to the outdoor unit 30, the control unit 31 generates a message including a CoAP header and including information related to the state change in the data, and sends it to the outdoor unit 30, wherein the method is specified as "INF" in the CoAP header, the need for a response is specified as "not required", and the need for retransmission is specified as "CON".

[0100] Each time the outdoor unit 30 receives a message sent from each indoor unit 50, it replies with an ACK message and stores information related to the state change of each indoor unit 50 in the storage unit 32 (steps S214 to S216). Here, the received message may be stored only in the volatile memory included in the storage unit 32, or may be copied and stored in the non-volatile memory after being stored in the volatile memory.

[0101] As described above, in the second embodiment, even in a situation where, for example, an operation instruction is sent simultaneously from the central control device 10 to each indoor unit 50, each indoor unit 50 detects a state change at the same time, and notifications related to the state change from each indoor unit 50 are executed simultaneously, each indoor unit 50 delays the notification related to the state change according to the sending time inherently determined by each device, thereby avoiding load concentration in the outdoor unit 30 on the receiving side.

[0102] In this embodiment, the structure is to notify the sending time from the outdoor unit 30 to each indoor unit 50, but the sending time can also be notified from the central control device 10 to each indoor unit 50, and the service inspector can be connected to the refrigeration and air conditioning related unit, and the sending time can be notified from the service inspector to each indoor unit 50.

[0103] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims rather than the above meaning, and is intended to include all changes within the meaning and scope equivalent to the claims. Explanation of symbols

[0104] 1Refrigeration and air conditioning related systems; 10. Centralized control device; 11. Control Department; 12 storage unit; 13 Ministry of Communications; 14 display unit; 15. Operation unit; 16 connection terminals; 30 outdoor units; 31 Control Department; 32 storage unit; 33 Ministry of Communications; 34~36 connection terminals; 50 indoor units; 51 Control Department; 52 storage unit; 53 Ministry of Communications; 54~55 connection terminals.

Claims

1. A communication method, wherein the communication method is a communication method for communicating data related to state changes of refrigeration and air conditioning related units between multiple communication nodes, characterized in that: First communication node When the second communication node detects the state change, a message is generated, the message including information related to the time when the second communication node sends the data to the communication node to which the data should be sent, Send the generated message to the second communication node.

2. The communication method according to claim 1, characterized in that: When the second communication node detects the state change, the second communication node delays transmission of the data based on the information related to the time included in the received message.

3. The communication method according to claim 1 or 2, characterized in that: The time is determined as the earliest time after the state change is detected among a plurality of times inherently determined by the second communication node.

4. The communication method according to claim 1 or 2, characterized in that: The timing is specified based on the elapsed time from the detection of the state change.

5. The communication method according to any one of claims 1 to 3, characterized in that: The time is defined based on the elapsed time from a reference time synchronized between the second communication nodes.

6. The communication method according to any one of claims 1 to 5, characterized in that: The timing is defined based on the number and order of communication nodes to which the data should be transmitted.

7. The communication method according to any one of claims 1 to 6, characterized in that: The first communication node is an outdoor unit, and the second communication node is an indoor unit.

8. The communication method according to claim 7, characterized in that: The first communication node also includes a centralized control device.

9. The communication method according to claim 7, characterized in that: The first communication node also includes a service inspector.

10. The communication method according to any one of claims 1 to 9, characterized in that: The message has a format specified by CoAP (Constrained Application Protocol), and the information related to the time is described in a payload included in the message.

11. A refrigeration and air conditioning related system, in which data related to state changes of refrigeration and air conditioning related units are communicated between a plurality of communication nodes, characterized in that: The first communication node comprises: Control Unit; and Ministry of Communications, When the second communication node detects the state change, the control unit generates a message including information related to a time when the second communication node transmits the data to the communication node to be transmitted, The communication unit transmits the message generated by the control unit to the second communication node.

12. A communication node, wherein the communication node is a communication node in a refrigeration and air conditioning related system, characterized in that: include: Control Department; as well as Ministry of Communications, The control unit generates a message when the other communication node detects a state change of the refrigeration and air conditioning related unit, wherein the message includes information related to the time when the other communication node sends data to the communication node to which the data should be sent. The communication unit transmits the message generated by the control unit to the other communication node.

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