JP7065386B2 - Communication systems, equipment control systems, communication devices, communication control methods and programs - Google Patents

Description

The present disclosure generally relates to a communication system, a device control system, a communication device, a communication control method and a program, and more particularly, a communication system including a first system and a plurality of second systems, a device control system, a communication device, and communication. Regarding control methods and programs.

Patent Document 1 describes a communication system in which a slave unit and a superposed communication means are connected in parallel to a master unit via a two-wire communication line. The master unit sends a first signal whose positive and negative polarities change to the communication line. The slave unit uses the first signal as a power source and communicates with the master unit by the first signal. The superimposed communication means uses the first signal as a power source and communicates with the master unit by the second signal superimposed on the first signal.

Japanese Unexamined Patent Publication No. 2009-055371

The communication system described in Patent Document 1 does not have a function of controlling communication between a plurality of second systems when a plurality of second systems (subsystems) are connected to the first system including the master unit. , It is difficult to realize cooperation between a plurality of second systems.

The present disclosure has been made in view of the above reasons, and an object of the present invention is to provide a communication system, a device control system, a communication device, a communication control method, and a program capable of easily realizing cooperation between a plurality of second systems.

The communication system according to one aspect of the present disclosure includes a first system, a plurality of interfaces, and a plurality of second systems. The first system includes one or more first terminals connected to a transmission line. The plurality of interfaces are connected to the transmission line and communicate with each other by a superposed signal. Each of the plurality of second systems includes a plurality of second terminals that communicate with each other by a second signal. The plurality of second systems are asynchronous with each other and are connected to the plurality of interfaces in a one-to-one correspondence. Each of the plurality of interfaces transfers the second signal received from the corresponding second system among the plurality of second systems to the other second system via the other interface by the superimposed signal. It is configured as follows. Each of the plurality of interfaces is configured to adjust the timing of transmitting the superimposed signal according to the state of the transmission line when transmitting the superimposed signal.

The device control system according to one aspect of the present disclosure includes the communication system. The one or more first terminals include a collective control terminal that collectively controls a plurality of devices, and the one or more second terminals include an individual control terminal that individually controls the plurality of devices for each device. ..

The communication device according to one aspect of the present disclosure is used in the communication system as one of the plurality of interfaces.

In the communication control method according to one aspect of the present disclosure, when transmitting a superimposed signal from each of a plurality of interfaces in a communication system, the timing of transmitting the superimposed signal is adjusted according to the state of a transmission line. The communication system includes a first system, a plurality of interfaces, and a plurality of second systems. The first system includes one or more first terminals connected to the transmission line. The plurality of interfaces are connected to the transmission line and communicate with each other by the superimposed signal. Each of the plurality of second systems includes a plurality of second terminals that communicate with each other by a second signal. The plurality of second systems are asynchronous with each other and are connected to the plurality of interfaces in a one-to-one correspondence. Each of the plurality of interfaces transfers the second signal received from the corresponding second system among the plurality of second systems to the other second system via the other interface by the superimposed signal. ..

The program according to one aspect of the present disclosure is a program for causing a computer system to execute the communication control method.

The present disclosure has an advantage that cooperation between a plurality of second systems can be easily realized.

FIG. 1 is a schematic system configuration diagram showing a communication system and a device control system according to the first embodiment. FIG. 2 is a schematic waveform diagram showing a signal format of the first signal used in the first system of the same communication system. FIG. 3 is a block diagram showing the configuration of the interface of the same communication system. FIG. 4 is a schematic waveform diagram for explaining the retransmission operation of the same communication system. FIG. 5 is a schematic waveform diagram for explaining the time-division transmission operation of the same communication system. FIG. 6 is a schematic waveform diagram for explaining the time-division transmission operation of the same communication system. FIG. 7A is a schematic waveform diagram showing the time-division transmission operation of the communication system of the above, in the case where the transmission start of the superimposed signal is not advanced. FIG. 7B shows a time-division transmission operation of the same communication system, and is a schematic waveform diagram when the transmission start of the superimposed signal is advanced. FIG. 8 is a schematic waveform diagram for explaining another time-division transmission operation of the same communication system. FIG. 9 is a schematic system configuration diagram showing a communication system according to the second embodiment.

(Embodiment 1)
(1) Overview The communication system according to the present embodiment is used in a facility such as an office building, a store, a hospital, a school or a factory, and is used for device control for controlling a device such as a lighting fixture installed in the facility. Configure the system. In the present embodiment, a case where the device control system using the communication system is a lighting control system for controlling the lighting equipment will be described as an example.

As shown in FIG. 1, the communication system 10 according to the present embodiment includes a first system 1, a plurality of (here, two) second systems 2A and 2B, and a plurality of (here, two) interfaces 3A. It is equipped with 3B. Hereinafter, when the plurality of second systems 2A and 2B are not particularly distinguished, each of the plurality of second systems 2A and 2B is referred to as "second system 2". Similarly, when the plurality of interfaces 3A and 3B are not particularly distinguished, each of the plurality of interfaces 3A and 3B is referred to as "interface 3". In the present embodiment, the first system 1 constitutes a "main system" which is an upper system in the communication system 10, and each second system 2 constitutes a "subsystem" which is a lower system in the communication system 10. do. Therefore, in the first system 1 which is the main system, a plurality of second systems 2 can be managed in an integrated manner.

Here, the interface 3 is a communication device having at least a communication function. In other words, the communication device is used in the communication system 10 as one of the plurality of interfaces 3.

The first system 1 includes one or more (here, four) first terminals 11A, 11B, 11C, 11D. Hereinafter, when a plurality of first terminals 11A, 11B, 11C, 11D are not particularly distinguished, each of the plurality of first terminals 11A, 11B, 11C, 11D is referred to as "first terminal 11". The first terminal 11 communicates by the first signal transmitted through the (first) transmission line 12.

The second system 2A includes one or more (here, three) second terminals 21A, 21B, 21E. Further, the other second system 2B includes one or more (here, three) second terminals 21C, 21D, 21F. Hereinafter, when a plurality of second terminals 21A, 21B, 21C, 21D, 21E, 21F are not particularly distinguished, each of the plurality of second terminals 21A, 21B, 21C, 21D, 21E, 21F is referred to as "second". It is called "terminal 21". The second terminal 21 communicates by the second signal transmitted through the (second) transmission line 22.

Here, the plurality of second systems 2A and 2B are asynchronous with each other. In the present embodiment, the second terminal 21 included in each second system 2 communicates with another second terminal 21 included in the same second system 2 by the second signal transmitted through the transmission line 22. , The second system 2 operates independently. That is, the second system 2 constructs an independent system. In the present embodiment, the plurality of independent second systems 2 are connected to the transmission line 12 of the first system 1 via the interface 3, so that the plurality of second systems 2 can cooperate with each other. It becomes.

As an example in FIG. 1, a plurality of (here, two) lighting fixtures 4A and 4B are connected to the first terminal 11A, and a plurality of (here, two) lighting fixtures 4C are connected to the first terminal 11B. , 4D is connected. Further, the lighting fixture 4A is connected to the second terminal 21A, the lighting fixture 4B is connected to the second terminal 21B, the lighting fixture 4C is connected to the second terminal 21C, and the lighting fixture 4D is connected to the second terminal 21D. Is connected. Hereinafter, when a plurality of lighting fixtures 4A, 4B, 4C, and 4D are not particularly distinguished, each of the plurality of lighting fixtures 4A, 4B, 4C, and 4D is referred to as "lighting fixture 4". These plurality of lighting fixtures 4 constitute a plurality of devices to be controlled by the device control system 100 using the communication system 10. In the present embodiment, the lighting fixture 4 as a control target will be described as not being included in the components of the communication system 10.

The plurality of interfaces 3A and 3B are connected to the transmission line 12 and communicate with each other by the superimposed signal superimposed on the first signal. The term "superimposition" as used in the present disclosure means that a plurality of signals transmitted on the same transmission line overlap each other. That is, the superimposed signal is a signal transmitted on the transmission line 12 together with the first signal in a state where the transmission line 12 is superimposed on the first signal to be transmitted. The plurality of second systems 2 are connected to the plurality of interfaces 3 in a one-to-one correspondence. In this embodiment, as an example, the second system 2A is associated with the interface 3A and is connected to the interface 3A. The second system 2B is associated with the interface 3B and is connected to the interface 3B. In other words, the second system 2A is connected to the transmission line 12 of the first system 1 via the interface 3A, and the second system 2B is connected to the transmission line 12 of the first system 1 via the interface 3B.

In this way, the interface 3 and the second system 2 are associated with each other on a one-to-one basis, and one interface 3 and one second system 2 form a pair. Hereinafter, among the plurality of second systems 2, the second system 2 corresponding to the specific interface 3, that is, the second system 2 directly connected to the specific interface 3, is referred to as the "second subordinate" of the interface 3. Also called "system 2". In the present embodiment, the second system 2A is under the control of the interface 3A, and the second system 2B is under the control of the interface 3B.

Then, each of the plurality of interfaces 3A and 3B receives the second signal received from the corresponding second system 2 among the plurality of second systems 2A and 2B as a superimposed signal via the other interface 3. It is configured to transfer to the second system 2. That is, the interface 3A transfers the second signal received from the corresponding second system 2A to the other second system 2B via the other interface 3B as a superimposed signal. On the other hand, the interface 3B transfers the second signal received from the corresponding second system 2B to the other second system 2A via the other interface 3A as a superimposed signal.

In short, the second system 2A is connected to the common transmission line 12 of the first system 1 via the interface 3A and the second system 2B is connected to the common transmission line 12 via the interface 3B. Therefore, when the plurality of interfaces 3A and 3B communicate with each other by the superimposed signal, data can be exchanged between different second systems 2A and 2B. As a result, even when the first system 1 is in operation, the transmission line 12 common to the first system 1 is used by using the superimposed signal superimposed on the first signal used in the first system 1. Therefore, a plurality of second systems 2A and 2B can be linked.

By the way, in the communication system 10 according to the present embodiment, each of the plurality of interfaces 3A and 3B is configured to adjust the timing of transmitting the superimposed signal according to the state of the transmission line 12 when transmitting the superimposed signal. Has been done. That is, when the interface 3 receives the second signal from the second system 2 under its control, the interface 3 does not immediately transmit the superimposed signal, but temporarily stores the data contained in the second signal and checks the timing. Functions as a buffer for transmitting superimposed signals. For example, when the interface 3 receives the second signal from the subordinate second system 2, if the first terminal 11 of the first system 1 is communicating, the interface 3 waits until the communication of the first terminal 11 is completed. Later, the superimposed signal is transmitted.

As described above, in the communication system 10, each interface 3 adjusts the timing of transmitting the superimposed signal to the transmission line 12 according to the state of the transmission line 12, so that each second system 2 considers the communication timing. It is possible to communicate with another second system 2 without any problems. Therefore, according to the communication system 10, there is an advantage that cooperation between a plurality of second systems 2 (subsystems) can be easily realized.

(2) Configuration Next, the configuration of the communication system 10 according to the present embodiment will be described in more detail with reference to FIG.

As described above, the communication system 10 includes a first system 1, a plurality of (here, two) second systems 2, and a plurality of (here, two) interfaces 3.

(2.1) First system The first system 1 includes a plurality of (here, four) first terminals 11A, 11B, 11C, 11D. The plurality of first terminals 11A, 11B, 11C, and 11D are all electrically connected to the two-wire transmission line 12. The plurality of first terminals 11A, 11B, 11C, 11D include three types of terminals, a "control terminal", a "monitoring terminal", and a "transmission unit". In the example of FIG. 1, the first terminals 11A and 11B are control terminals, the first terminal 11C is a monitoring terminal, and the first terminal 11D is a transmission unit.

The first terminals 11A and 11B as control terminals control the equipment (lighting equipment 4) to be controlled by the equipment control system 100. As an example in FIG. 1, the first terminals 11A and 11B are separate from the lighting fixture 4 to be controlled. Each of the first terminals 11A and 11B controls a relay built in the first terminals 11A and 11B or a remote control relay according to a message transmitted from the first terminal 11D as a transmission unit, and controls a lighting fixture 4 Has a function to control on / off of. The "telegram" referred to in the present disclosure is a set of data transmitted and received between devices, which is described according to a predetermined format. In the example of FIG. 1, the first terminal 11A has a plurality of (here, two) lighting fixtures 4A by turning on / off a relay (or a remote control relay) provided on the power supply path to the lighting fixtures 4A and 4B. , 4B is a "batch control terminal" that collectively controls. The first terminal 11B collectively controls a plurality of (here, two) lighting fixtures 4C and 4D by turning on / off a relay (or remote control relay) provided on the power supply path to the lighting fixtures 4C and 4D. It is a "batch control terminal". However, not limited to this example, the first terminals 11A and 11B as control terminals may be integrally configured with the lighting fixture 4 to be controlled, and can control dimming or toning of the lighting fixture 4. It may have a function to perform. Each of the first terminals 11A and 11B has a memory for storing its own address assigned individually. When each of the first terminals 11A and 11B has a plurality of relays, a memory unique to each relay is stored in the memory.

The first terminal 11C as a monitoring terminal is composed of, for example, a switch device or a sensor device that is attached to a wall or the like and accepts a user's operation. The sensor device referred to here is, for example, a motion sensor, an illuminance sensor, a temperature sensor, or the like. The first terminal 11C as a monitoring terminal becomes the first terminal 11D as a transmission unit when a specific event occurs, for example, a switch detects a user's operation or a sensor detects the presence of a person. Send a message to it. In the example of FIG. 1, the first terminal 11C is a switch device that accepts a user's operation, and when the user's operation is detected by any of a plurality of switches, a message corresponding to the operated switch is transmitted. The first terminal 11C has a memory that stores its own address assigned individually. When the first terminal 11C has a plurality of switches, a unique address for each switch is stored in the memory.

The first terminal 11D as a transmission unit repeatedly transmits, for example, the first signal Si1 in the signal format as shown in FIG. 2 to the two-wire transmission line 12. Further, the first terminal 11D as a transmission unit has a memory that stores the correspondence between the addresses of the first terminals 11 other than the first terminal 11D. Here, the first signal Si1 is a time-division type signal having a voltage waveform divided into a plurality of regions in the time axis direction. In the example of FIG. 2, the first signal Si1 has an interrupt band T1, a short circuit detection band T2, a rest band T3, a spare interrupt band T4, a spare band T5, a transmission band T6, and a reply band T7. It is a multipolar (± 24V) time-division multiplex signal consisting of seven regions of. Here, a series of sections starting from the interrupt band T1 in the first signal Si1 and ending with the reply band T7 is defined as one frame.

The interrupt band T1 is a period for detecting the presence or absence of an interrupt signal described later, and the short circuit detection band T2 is a period for detecting a short circuit. The rest zone T3 is a period for when the processing is not in time. The preliminary interrupt zone T4 is a period for detecting the presence or absence of a secondary interrupt, and the spare interrupt zone T5 is a period set according to the interrupt zone T1 and the short circuit detection zone T2. The transmission band T6 is a period for the first terminal 11D (transmission unit) to transmit data to the other first terminal 11, and the reply band T7 is the period for the first terminal 11D (transmission unit) to transmit data from the other first terminal 11. It is a period for receiving the return data of.

The first terminal 11D as a transmission unit always transmits the first signal Si1 whose mode data is the normal mode, and periodically changes the address data included in the transmission band T6 of the first signal Si1. Constant polling is performed to sequentially access the other plurality of first terminals 11. At the time of constant polling, the first terminal 11 whose address data included in the transmission band T6 matches its own address receives the message included in the transmission band T6, and sends the message in the next reply band T7. 1 Send to terminal 11D. Here, the first terminal 11 returns a message by a current mode signal synchronized with the reply band T7 of the first signal Si1. The "current mode signal" referred to in the present disclosure is represented by a current change caused by switching between a state in which the lines of the two-wire transmission line 12 are open and a state in which a low impedance element is connected between the lines. It is a signal. As a result, one or more first terminals 11 included in the first system 1 communicate with the first signal Si1 transmitted through the transmission line 12. The operating power of the internal circuit of the first terminal 11 other than the first terminal 11D is generated by rectifying and stabilizing the first signal Si1.

(2.2) Second system The second system 2A includes a plurality of (here, three) second terminals 21A, 21B, 21E. The plurality of second terminals 21A, 21B, 21E are all electrically connected to the two-wire transmission line 22 in the second system 2A. The second system 2B includes a plurality of (here, three) second terminals 21C, 21D, and 21F, similarly to the second system 2A. The plurality of second terminals 21C, 21D, and 21F are all electrically connected to the two-wire transmission line 22 in the second system 2B. As an example in this embodiment, the second systems 2A and 2B are systems compliant with the DALI (Digital Addressable Lighting Interface) standard. The plurality of second terminals 21A, 21B, 21C, 21D, 21E, 21F include two types of terminals, a "slave" and a "master". In the example of FIG. 1, the second terminals 21A, 21B, 21C, and 21D are slaves, and the second terminals 21E and 21F are masters, respectively.

The second terminals 21A, 21B, 21C, 21D as slaves control the equipment (lighting equipment 4) to be controlled by the equipment control system 100. As an example in FIG. 1, the second terminals 21A, 21B, 21C, and 21D are separate from the lighting fixture 4 to be controlled. Each of the second terminals 21A, 21B, 21C, 21D turns on the lighting fixture 4 connected to the second terminals 21A, 21B, 21C, 21D according to the message transmitted from the second terminals 21E, 21F as the master. It has a function to control / off, dimming, toning, etc. In the example of FIG. 1, the second terminal 21A is connected to the lighting fixture 4A, the second terminal 21B is connected to the lighting fixture 4B, and each of the second terminals 21A and 21B is a plurality of units (here, two units). It is an "individual control terminal" that individually controls the lighting fixtures 4A and 4B of the above for each lighting fixture 4. The second terminal 21C is connected to the lighting fixture 4C, the second terminal 21D is connected to the lighting fixture 4D, and each of the second terminals 21C and 21D is connected to a plurality of (here, two) lighting fixtures 4C and 4D. It is an "individual control terminal" that individually controls each lighting fixture 4. However, not limited to this example, the second terminals 21A, 21B, 21C, 21D as slaves may be integrally configured with the lighting fixture 4 to be controlled. Each of the second terminals 21A, 21B, 21C, and 21D has a memory for storing its own address assigned individually.

The second terminals 21E and 21F as masters are composed of, for example, a switch device or a sensor device that is attached to a wall or the like and accepts a user's operation. The sensor device referred to here is, for example, a motion sensor, an illuminance sensor, a temperature sensor, or the like. The second terminals 21E and 21F as masters are the second terminals 21A, 21B and 21C when a specific event occurs, for example, a switch detects a user's operation or a sensor detects the presence of a person. , 21D sends a message. In the example of FIG. 1, each of the second terminals 21E and 21F is a switch device that accepts a user's operation, and when the user's operation is detected by any of a plurality of switches, a message corresponding to the operated switch is displayed. To send. Each of the second terminals 21E and 21F has a memory for storing its own address assigned individually.

One or more second terminals 21 included in the second system 2 communicate with the second signal transmitted through the transmission line 22. Here, the communication protocol of the second system 2, that is, the protocol of the second signal is different from at least the communication protocol of the first system 1, that is, the protocol of the first signal Si1.

(2.3) Interfaces A plurality of (here, two) interfaces 3A and 3B are all electrically connected to the transmission line 12 of the first system 1. The plurality of interfaces 3A and 3B are configured to be communicable with each other via the transmission line 12 by the superimposed signal Si0 superimposed on the first signal Si1. Further, the interface 3A is electrically connected to the transmission line 22 of the second system 2A. The interface 3B is electrically connected to the transmission line 22 of the second system 2B. As a result, a plurality of (here, two) second systems 2A and 2B that are asynchronous to each other are connected to the transmission line 12 of the first system 1 via the interfaces 3A and 3B. As a result, the plurality of second systems 2A and 2B independent of each other can cooperate with each other via the interfaces 3A and 3B and the transmission line 12.

As shown in FIG. 3, each interface 3 includes a control unit 30, a rectifier 31, a superposed signal transmitting unit 32, a superposed signal receiving unit 33, a first signal transmitting unit 34, and a first signal receiving unit 35. , A second signal transmission / reception unit 36, and an insulation circuit 37. Each interface 3 further includes a collision detection unit 38 and a priority setting unit 39.

The control unit 30 controls a superimposition signal transmission unit 32, a superimposition signal reception unit 33, a first signal transmission unit 34, a first signal reception unit 35, a second signal transmission / reception unit 36, a collision detection unit 38, and a priority setting unit 39. do. The control unit 30 is composed of a CPU (Central Processing Unit) and a microcomputer having a memory as a main configuration. In other words, the control unit 30 is realized by a computer having a CPU and a memory, and the computer functions as the control unit 30 by executing a program stored in the memory by the CPU. Although the program is recorded in advance in the memory of the control unit 30 here, it may be recorded and provided through a telecommunication line such as the Internet or a non-temporary recording medium such as a memory card.

The rectifier 31 is composed of a diode bridge (denoted as "DB" in FIG. 3). The rectifier 31 is electrically connected to the transmission line 12 of the first system 1.

The superimposed signal transmission unit 32 is connected to the transmission line 12 of the first system 1 via the rectifier 31. The superimposed signal transmission unit 32 transmits the superimposed signal Si0 superimposed on the first signal Si1. The superimposed signal Si0 is a signal having a sufficiently high frequency as compared with the first signal, and the amount of data that can be transmitted per frame (of the first signal) is sufficiently large. Therefore, the communication using the superimposed signal Si0 can increase the communication speed as compared with the communication using the first signal, and is suitable for transmitting information having a relatively large amount of data such as an analog amount. Hereinafter, when distinguishing between the superimposed signal Si0 from the interface 3A and the superimposed signal Si0 from the interface 3B, the superimposed signal Si0 from the interface 3A is referred to as “Si0-1”, and the superimposed signal Si0 from the interface 3B is referred to as “Si0-”. 2 "(see Fig. 4). FIG. 4 and the like merely schematically show how the superimposed signal Si0 is superimposed on the first signal Si1, and actually, the waveform obtained by synthesizing the superimposed signal Si0 on the first signal Si1 as shown in the figure. The signal of is not generated in the transmission line 12.

The superimposed signal receiving unit 33 is connected to the transmission line 12 of the first system 1 via the rectifier 31. The superimposed signal receiving unit 33 receives the superimposed signal Si0 superimposed on the first signal Si1.

The first signal transmission unit 34 is connected to the transmission line 12 of the first system 1 via the rectifier 31. The first signal transmission unit 34 transmits the first signal Si1.

The first signal receiving unit 35 is connected to the transmission line 12 of the first system 1 via the rectifier 31. The first signal receiving unit 35 receives the first signal Si1.

The second signal transmission / reception unit 36 is electrically connected to the transmission line 22 of the second system 2 under the interface 3. The second signal transmission / reception unit 36 can perform communication in accordance with the communication protocol of the second system 2. The second signal transmission / reception unit 36 transmits and receives the second signal to and from the second terminal 21 included in the second system 2 under the interface 3 via the transmission line 22. That is, the second signal transmission / reception unit 36 transmits / receives a message to / from the second terminal 21 in both directions by wire communication using the second signal.

The insulation circuit 37 is inserted between the control unit 30 and the second signal transmission / reception unit 36. The insulation circuit 37 electrically insulates the control unit 30 and the second signal transmission / reception unit 36.

The collision detection unit 38 is connected to the superimposed signal receiving unit 33 and detects a collision between the superimposed signals Si0 in the transmission line 12. For example, when the superimposed signal transmitting unit 32 of the interface 3A and the superimposed signal transmitting unit 32 of the interface 3B simultaneously transmit the superimposed signal Si0, a collision between the superimposed signals Si0 may occur on the transmission line 12. In such a case, the collision detection unit 38 of each interface 3 detects the occurrence of a collision between the superimposed signals Si0.

The priority setting unit 39 receives the priority setting information. That is, the priority is set in each interface 3 according to the priority setting information received by the priority setting unit 39. In the present embodiment, as an example, it is assumed that the priority "1" is set for the interface 3A and the priority "2" is set for the interface 3B. Here, the interface 3 can preferentially transmit the superimposed signal Si0 as the priority is higher (the numerical value is smaller). The priority setting information may be manually input by the user using, for example, a DIP switch or the like, or may be set by a setting terminal or the like and input to the interface 3.

The interface 3 configured as described above transfers the second signal received from the subordinate second system 2 to the other second system 2 via the other interface 3 by the superimposed signal Si0. That is, the interface 3A transfers the second signal received from the subordinate second system 2A to the other second system 2B via the other interface 3B by the superimposed signal Si0. On the other hand, the interface 3B transfers the second signal received from the subordinate second system 2B to the other second system 2A via the other interface 3A by the superimposed signal Si0.

Further, when transmitting the superimposed signal Si0, the interface 3 adjusts the timing of transmitting the superimposed signal Si0 according to the state of the transmission line 12. That is, when the interface 3 receives the second signal from the second system 2 under its control, the interface 3 does not immediately transmit the superimposed signal Si0, but temporarily stores the data included in the second signal and sets the timing. It functions as a buffer for transmitting the superimposed signal Si0. For example, when the interface 3 receives the second signal from the subordinate second system 2, if the first terminal 11 of the first system 1 is communicating, the interface 3 waits until the communication of the first terminal 11 is completed. Later, the superimposed signal Si0 is transmitted.

Specifically, the control unit 30 of the interface 3 has a function of monitoring the first signal Si1 by the first signal receiving unit 35 and analyzing the transmission status (hereinafter referred to as “state”) of the first signal Si1. are doing. The interface 3 determines from the analysis result of the state by the control unit 30 whether or not it is in the superimposition possible band suitable for superimposing the superimposition signal Si0, and at the timing determined to be the superimposition possible band, the interface 3 is sent to the superimposition signal transmission unit 32. And the superimposed signal Si0 is transmitted.

As an example in the present embodiment, the superimposing band is a region (section) of the rest band T3, the preliminary interrupt band T4, the spare band T5, and the reply band T7 in the first signal Si1. That is, the rest band T3, the preliminary interrupt band T4, the spare band T5, and the reply band T7 are less likely to affect the first signal Si1 even if the superimposed signal Si0 is superimposed, and the superimposed signal Si0 is also affected by the first signal Si1. Hard to receive. In particular, in the reply band T7, the signal level of the first signal Si1 is stable for a longer time than in other regions, and the ratio of the first signal Si1 to one frame is large. Is suitable.

In the other regions (interruption band T1, short circuit detection band T2, and transmission band T6), the time during which the signal level of the first signal Si1 is stable is relatively short, and when the superimposed signal Si0 is superimposed, the first signal is superimposed. Si1 is easily affected, and the superimposed signal Si0 is also easily affected by the first signal Si1. Therefore, in the present embodiment, the interrupt band T1, the short circuit detection band T2, and the transmission band T6 are regions that are not used for superimposing the superimposition signal Si0 (hereinafter, referred to as “non-superimposition band”).

Further, the control unit 30 determines that even if the reply band T7 is used, the reply band T7 used for returning the current mode signal from the first terminal 11 cannot be superimposed. That is, the interface 3 uses the reply band T7 in which the current mode signal is not returned from the first terminal 11 for superimposing the superimposition signal Si0 as a superimposition possible band suitable for superimposing the superimposition signal Si0. Therefore, the control unit 30 determines whether or not the current mode signal is returned in the region recognized as the reply band T7 by the first signal receiving unit 35, and superimposes the reply band T7 on which the return band T7 is not returned. Judge.

(3) Operation Next, the operation of the communication system 10 according to the present embodiment will be described. Hereinafter, the three operations of the operation of the first system 1, the operation of the second system 2, and the cooperation operation between the plurality of second systems 2 in the communication system 10 will be described in order. After that, a retransmission operation and a time-division transmission operation, which are operations for coping with collisions between superimposed signals Si0 from a plurality of interfaces 3, will be described in order. In the present embodiment, the retransmission operation and the time-division transmission operation will be described as being selectively adopted. However, the retransmission operation and the time-division transmission operation may be adopted in combination.

(3.1) Operation of the first system First, the operation of the first system 1 will be described. Here, in the communication system 10 of FIG. 1, the operation of the first system 1 when the switch corresponding to the first terminal 11A is operated by the first terminal 11C as a monitoring terminal will be described.

The first terminal 11C generates an interrupt signal when a specific event such as a switch being operated occurs. When the first terminal 11D as a transmission unit detects an interrupt signal generated in the first terminal 11C in the interrupt band T1 of the first frame of the first signal Si1, it is included in the transmission band T6 of the first signal Si1. Switch mode data from normal mode to interrupt polling mode. In the interrupt polling mode, the first terminal 11D identifies the address of the first terminal 11C from which the interrupt signal is generated by acquiring the address of the first terminal 11C from which the interrupt signal is generated. Then, the first terminal 11D transmits a reply request message to the first terminal 11C from which the interrupt signal is generated, and receives a monitoring message (monitoring message) from the first terminal 11C by the current mode signal. do.

Upon receiving the monitoring message from the first terminal 11C, the first terminal 11D transmits a control message (control message) to the first terminal 11A corresponding to the address included in the monitoring message. The control message transmitted at this time includes at least the control content and the address to which the control message is addressed. The first terminal 11A, which has received the control message, controls on / off of the lighting fixtures 4A and 4B to be controlled according to the control content of the control message.

As described above, in the first system 1, when a specific event occurs in the first terminal 11C as a monitoring terminal and an interrupt signal is generated, the first terminal 11D as a transmission unit is changed to a second terminal as a control terminal. A control message is transmitted to the terminal 11A. In short, in the first system 1, the first terminal 11C and the first terminal 11A communicate with each other via the first terminal 11D as a transmission unit according to the protocol of the polling selection method. As a result, for example, when the switch of the first terminal 11C is operated, the relay is controlled by the first terminal 11A corresponding to this switch, so that the lighting fixtures 4A and 4B corresponding to this switch are controlled.

(3.2) Operation of the second system Next, the operation of the second system 2 will be described. Here, in the communication system 10 of FIG. 1, the operation of the second system 2A when the switch corresponding to the second terminal 21A is operated by the second terminal 21E as a master will be described.

When a specific event such as the operation of a switch occurs, the second terminal 21E transmits a control message (control message) corresponding to the operated switch to the transmission line 22 as a second signal. This second signal is transmitted toward the second terminal 21A corresponding to the operated switch. The control message transmitted at this time includes at least the control content and the address to which the control message is addressed. Upon receiving the control message, the second terminal 21A controls, for example, on / off of the lighting fixture 4A to be controlled according to the control content of the control message.

As described above, in the second system 2A, when a specific event occurs in the second terminal 21E as a master, a control message is transmitted to the second terminal 21A as a slave. In short, in the second system 2, the second terminal 21E and the second terminal 21A directly communicate with each other. As a result, for example, when the switch of the second terminal 21E is operated, the second terminal 21A corresponding to this switch is controlled, so that the lighting fixture 4A corresponding to this switch is controlled.

(3.3) Coordination operation between a plurality of second systems Next, a cooperation operation between a plurality of second systems 2 will be described. Here, in the communication system 10 of FIG. 1, the second terminal 21E as the master of the second system 2A operates the switch corresponding to the second terminal 21C of the other second system 2B. The cooperative operation of the system 2A and the second system 2B will be described.

When a specific event such as the operation of a switch occurs, the second terminal 21E transmits a control message (control message) corresponding to the operated switch to the transmission line 22 as a second signal. This second signal is transmitted toward the second terminal 21C corresponding to the operated switch. The control message transmitted at this time includes at least the control content and the address to which the control message is addressed.

Here, since the second terminal 21C does not exist on the transmission line 22 of the second system 2A to which the second terminal 21E is connected, the control message is the interface 3A, the transmission line 12 of the first system 1, and the interface 3B. Is transmitted to the second terminal 21C through this order. That is, first, the interface 3A connected to the second system 2A receives the second signal transmitted from the second terminal 21E, and thereby acquires the control message from the subordinate second system 2A. The interface 3A that has acquired the control message includes the control message in the superimposed signal Si0 superimposed on the first signal Si1, and transmits the superimposed signal Si0 to the interface 3B through the transmission line 12 of the first system 1. .. At this time, the interface 3A adjusts the timing of transmitting the superimposed signal Si0 according to the state of the transmission line 12. For example, as described above, the interface 3A transmits the superimposition signal Si0 in accordance with the superimposition possible band including the rest band T3, the preliminary interrupt band T4, the spare band T5, or the reply band T7 of the first signal Si1.

When the interface 3B receives the superimposed signal Si0 from the interface 3A, the interface 3B includes the control message included in the superimposed signal Si0 in the second signal and transmits the control message to the transmission line 22 of the subordinate second system 2B. Upon receiving the second signal from the interface 3B, the second terminal 21C controls, for example, on / off of the lighting fixture 4C to be controlled according to the control content of the control message.

As described above, the interface 3A transfers the second signal (control message) received from the subordinate second system 2A to the other second system 2B via the other interface 3B by the superimposed signal Si0. Therefore, when a specific event occurs in the second terminal 21E as the master in the second system 2A, the control message is transmitted to the second terminal 21C as the slave in the other second system 2B. As a result, for example, when the switch of the second terminal 21E is operated, the second terminal 21C corresponding to this switch is controlled, so that the lighting fixture 4C corresponding to this switch is controlled. Therefore, by connecting a plurality of second systems 2A and 2B independent of each other to the transmission line 12 of the first system 1 via the interface 3, it is possible to cooperate between the plurality of second systems 2A and 2B. Become.

(3.4) Retransmission Operation Next, a retransmission operation, which is an operation for dealing with a collision between superimposed signals Si0 from a plurality of interfaces 3, will be described. Here, in the communication system 10 of FIG. 1, the retransmission operation when the superimposed signals Si0 collide with each other due to the simultaneous transmission of the superimposed signals Si0 by the interface 3A and the interface 3B will be described.

The plurality of second systems 2 are asynchronous to each other in the first place, and each of the plurality of second systems 2 operates independently. Therefore, in the plurality of interfaces 3, telegrams (second signals) may be simultaneously received from the second system 2 under their respective control, and in such a case, the superimposed signal Si0 is simultaneously transmitted from the plurality of interfaces 3. There are times. As a result, the superimposed signals Si0 transmitted from the plurality of interfaces 3 may collide with each other on the transmission line 12, and the superimposed signals Si0 may not be received normally.

Therefore, in the communication system 10 according to the present embodiment, when each of the plurality of interfaces 3 collides with the signal (superimposed signal Si0) transmitted from the other interface 3 with respect to the superimposed signal Si0, the superimposed signal Si0 Resend. Specifically, when each of the plurality of interfaces 3 detects the occurrence of a collision between the superimposed signals Si0 on the transmission line 12 by the collision detection unit 38, after the waiting time (backoff time) has elapsed, each of the plurality of interfaces 3 has elapsed. The superimposed signal Si0 is retransmitted. Here, each of the plurality of interfaces 3 transmits the superimposed signal Si0 after a random waiting time has elapsed from the occurrence of the collision when retransmitting the superimposed signal Si0. That is, each of the plurality of interfaces 3 retransmits the superimposed signal Si0 after a waiting time of a random length has elapsed from the time when the collision detection unit 38 detects the occurrence of a collision between the superimposed signals Si0.

Further, in the present embodiment, each of the plurality of interfaces 3 transmits the superimposed signal Si0 at the timing when the signal is not transmitted from the other interface 3. Specifically, when the collision detection unit 38 detects that the superimposed signal Si0 is transmitted from the other interface 3 on the transmission path 12 of each of the plurality of interfaces 3, the superimposed signal Si0. Put the transmission on hold. Then, each of the plurality of interfaces 3 waits until the transmission of the superimposed signal Si0 from the other interface 3 is completed, and then transmits the superimposed signal Si0. This function is also effective when each of the plurality of interfaces 3 retransmits the superimposed signal Si0, that is, when the retransmission operation is performed.

By the above-mentioned retransmission operation, for example, as shown in FIG. 4, the superimposed signal Si0 is retransmitted. In the example of FIG. 4, a collision between the superimposed signal Si0-1 from the interface 3A and the superimposed signal Si0-2 from the interface 3B occurs in the reply band T7 of the first frame F1 of the first signal Si1. ("C1" in the figure).

In this case, the interface 3A of the second frame F2, which is the first superimposition possible band after the lapse of a random waiting time from the time when the occurrence of the collision between the superimposition signals Si0-1 and Si0-2 is detected. The superimposed signal Si0-1 is retransmitted to the rest zone T3. At this time, the interface 3A transmits the superimposed signal Si0-1 after confirming that the superimposed signal Si0-2 has not been transmitted from the other interface 3B. On the other hand, the interface 3B is a preliminary interrupt of the second frame F2, which is the first superimposition possible band after a random waiting time has elapsed from the time when the occurrence of the collision between the superimposition signals Si0-1 and Si0-2 is detected. The superimposed signal Si0-2 is retransmitted to the inclusion band T4. At this time, the interface 3B transmits the superimposed signal Si0-2 after confirming that the superimposed signal Si0-1 has not been transmitted from the other interface 3A. As a result, in the second frame F2 of the first signal Si1, the superimposed signals Si0-1 and Si0-2 from each interface 3 are transmitted without colliding with each other.

(3.5) Time-division transmission operation Next, a time-division transmission operation, which is an operation for dealing with a collision between superimposed signals Si0 from a plurality of interfaces 3, will be described. Here, it is assumed that the communication system 10 includes two interfaces 3C and 3D (see FIG. 9) and two second systems 2C and 2D (see FIG. 9) in addition to the example of FIG. The second system 2C is connected to the transmission line 12 of the first system 1 via the interface 3C, and the second system 2D is connected to the transmission line 12 of the first system 1 via the interface 3D. Hereinafter, when distinguishing between the superimposed signal Si0 from the interface 3C and the superimposed signal Si0 from the interface 3D, the superimposed signal Si0 from the interface 3C is referred to as "Si0-3", and the superimposed signal Si0 from the interface 3D is referred to as "Si0-". 4 ”(see Fig. 5).

As described in the column of "(3.4) Retransmission operation", in the plurality of interfaces 3, telegrams may be simultaneously received from the second system 2 under each interface 3, and in such a case, a plurality of interfaces may be received at the same time. The superimposed signal Si0 may be transmitted from the interface 3 at the same time. In the communication system 10, by adopting a time-division transmission operation instead of the retransmission operation, it is possible to deal with such a collision between the superimposed signals Si0.

That is, in the communication system 10 according to the present embodiment, the first signal Si1 is a periodic signal, and each of the plurality of interfaces 3 is set in one frame of the first signal Si1 as shown in FIG. A plurality of time slots Ts1 to Ts4 are assigned. Each of the plurality of interfaces 3 transmits the superimposed signal Si0 in the corresponding time slot among the plurality of time slots Ts1 to Ts4. Specifically, as shown in FIG. 5, a plurality of (here, four) times corresponding to a plurality of (here, four) interfaces 3 are provided in the reply band T7 of the first signal Si1, which is a superimposing band. Slots Ts1 to Ts4 are set.

Here, the priority is set in each interface 3 according to the priority setting information received by the priority setting unit 39. A plurality of time slots Ts1 to Ts4 are assigned to the plurality of interfaces 3 according to their priorities. Here, it is assumed that the higher priority is set in the order of interfaces 3A, 3B, 3C, and 3D for each of the plurality of interfaces 3. Therefore, the interface 3A is assigned the time slot Ts1, the interface 3B is assigned the time slot Ts2, the interface 3C is assigned the time slot Ts3, and the interface 3D is assigned the time slot Ts4.

Further, the plurality of time slots Ts1 to Ts4 include a first slot and a second slot. Then, the start point of the second slot is located between the start point and the end point of the first slot, and the end point of the first slot is located between the start point and the end point of the second slot. Here, the first slot and the second slot are a pair of adjacent time slots among the plurality of time slots Ts1 to Ts4. Therefore, for example, focusing on the pair of time slots Ts1 and Ts2, the time slot Ts1 is the first slot and the time slot Ts2 is the second slot. As shown in FIG. 5, the latter half of the time slot Ts1 which is the first slot overlaps with the first half of the time slot Ts2 which is the second slot. Similarly, focusing on the pair of time slots Ts2 and Ts3, the time slot Ts2 is the first slot and the time slot Ts3 is the second slot. The latter half of the time slot Ts2, which is the first slot, overlaps with the first half of the time slot Ts3, which is the second slot. Similarly, a part of the time slots Ts3 and Ts4 overlap each other. In other words, each of the plurality of time slots Ts1 to Ts4 includes an overlap period that overlaps with the other time slots Ts1 to Ts4. That is, the plurality of time slots Ts1 to Ts4 are set slightly offset in the time axis direction (time less than each time slot).

Further, in FIG. 5, only the reply band T7 of the first signal Si1 is shown, but each of the rest band T3, the preliminary interrupt band T4, and the spare band T5, which are superimposing bands other than the reply band T7, is also shown. Similar to the reply band T7, a plurality of time slots Ts1 to Ts4 are set. For the plurality of time slots Ts1 to Ts4 set in each of the rest zone T3, the spare interrupt zone T4, and the spare zone T5, little by little in the time axis direction (time less than each time slot) so that an overlap period occurs. It is set to be offset (by each).

Further, in the present embodiment, each of the plurality of interfaces 3 transmits the superimposed signal Si0 at the timing when the signal is not transmitted from the other interface 3. Specifically, when the collision detection unit 38 detects that the superimposed signal Si0 is transmitted from the other interface 3 on the transmission path 12 of each of the plurality of interfaces 3, the superimposed signal Si0. Put the transmission on hold. Then, each of the plurality of interfaces 3 waits until the transmission of the superimposed signal Si0 from the other interface 3 is completed, and then transmits the superimposed signal Si0.

By the time-division transmission operation described above, for example, as shown in FIG. 6, the superimposed signal Si0 is transmitted by the time-division method. In the example of FIG. 6, it is assumed that the two interfaces 3A and 3B attempt to transmit the superimposed signals Si0-1 and Si0-2 in the rest zone T3 of the first frame F1 of the first signal Si1. Further, in the example of FIG. 6, in the reply band T7 of the first frame F1 of the first signal Si1, the three interfaces 3A, 3B, and 3C attempted to transmit the superimposed signals Si0-1, Si0-2, and Si0-3. I'm assuming a case. In FIG. 6, the superimposed signal Si0 that was not actually transmitted is shown by a broken line.

In this case, first, in the rest zone T3 of the first frame F1, the interface 3A transmits the superimposed signal Si0-1 before the interface 3B, which has a lower priority than the interface 3A. As a result, when the interface 3B attempts to transmit the superimposed signal Si0-2, the superimposed signal Si0-1 from the other interface 3A has already been transmitted. Therefore, the interface 3B does not transmit the superimposed signal Si0-2 in the rest zone T3 of the first frame F1, and the superimposed signal Si0 in the preliminary interrupt band T4 of the first frame F1 which is the first superimposition possible band thereafter. -Send -2. At this time, the interface 3B transmits the superimposed signal Si0-2 after confirming that the superimposed signal Si0-1 has not been transmitted from the other interface 3A.

Further, in the reply band T7 of the first frame F1, the interface 3A transmits the superimposed signal Si0-1 before the interfaces 3B and 3C having a lower priority than the interface 3A. As a result, when the interfaces 3B and 3C try to transmit the superimposed signals Si0-2 and Si0-3, the superimposed signals Si0-1 from the other interface 3A have already been transmitted. Therefore, the interfaces 3B and 3C do not transmit the superimposed signals Si0-2 and Si0-3 in the reply band T7 of the first frame F1, but are in the rest band T3 of the second frame F2 which is the first superimposition possible band thereafter. Attempts to transmit the superimposed signals Si0-2 and Si0-3.

Then, in the rest zone T3 of the second frame F2, the interface 3B transmits the superimposed signal Si0-2 before the interface 3C having a lower priority than the interface 3B. As a result, when the interface 3C attempts to transmit the superimposed signal Si0-3, the superimposed signal Si0-2 from the other interface 3B has already been transmitted. Therefore, the interface 3C does not transmit the superimposed signal Si0-3 in the rest zone T3 of the second frame F2, and the superimposed signal Si0 in the preliminary interrupt band T4 of the second frame F2 which is the first superimposition possible band thereafter. Send -3. At this time, the interface 3C transmits the superimposed signal Si0-3 after confirming that the superimposed signals Si0-1 and Si0-2 have not been transmitted from the other interfaces 3A and 3B.

As a result, the superimposed signals Si0-1, Si0-2, and Si0-3 from each interface 3 are transmitted over the first frame F1 and the second frame F2 of the first signal Si1 without colliding with each other. ..

By the way, in the time division operation, each interface 3 transmits the superimposed signal Si0 before the start of the time slot assigned to itself when there is no transmission of the superimposed signal Si0 from another interface 3 having a higher priority than itself. You may. That is, the interface 3 to which the second slot is assigned is after the start point of the first slot and before the start point of the second slot when no signal is transmitted from the other interface 3 to the first slot. Transmission of the superimposed signal Si0 may be started.

For example, when focusing on the pair of time slots Ts1 and Ts2, the interface 3B to which the time slot Ts2, which is the second slot, is assigned can accelerate the transmission start time of the superimposed signal Si0-2. In short, as shown in FIG. 7A, when the interface 3B transmits the superimposed signal Si0-2 in the reply band T7, the interface 3B normally transmits the superimposed signal Si0-2 in the time slot Ts2 assigned to itself. .. On the other hand, as shown in FIG. 7B, if the superimposed signal Si0-1 is not transmitted from the other interface 3A to the time slot Ts1 which is the first slot, the interface 3B starts the transmission of the superimposed signal Si0-2. You can advance the time point. That is, in the example of FIG. 7B, the interface 3B starts transmitting the superimposed signal Si0-2 after the start point of the time slot Ts1 and before the start point of the time slot Ts2. As described above, the interface 3B can transmit the superimposed signal Si0-2 at an early stage by accelerating the start of the transmission of the superimposed signal Si0-2. In the examples of FIGS. 7A and 7B, the delay time from the start point of the reply band T7 to the start time of transmission of the superimposed signal Si0-2 is set to "Td1" by accelerating the transmission start time of the superimposed signal Si0-2. Is shortened to "Td2" (Td1> Td2).

Further, as another example of the time-division transmission operation, for example, as shown in FIG. 8, a plurality of time slots Ts1 to Ts4 may be set. In the example of FIG. 8, each of the plurality of time slots Ts1 to Ts4 does not include an overlap period overlapping with the other time slots Ts1 to Ts4. Here, the rest band T3 of the first signal Si1 constitutes the time slot Ts1, the spare interrupt band T4 constitutes the time slot Ts2, the spare band T5 constitutes the time slot Ts3, and the reply band T7 constitutes the time slot Ts4. That is, in the example of FIG. 8, the plurality of time slots Ts1 to Ts4 are set to be dispersed in the time axis direction, and there is no overlapping portion with each other.

In this case, the superimposed signals Si0-1, Si0-2, Si0-3, and Si0-4 from each interface 3 can be transmitted without colliding with each other within one frame of the first signal Si1.

(4) Modification Example 1 is only one of various embodiments of the present disclosure. The first embodiment can be changed in various ways depending on the design and the like as long as the object of the present disclosure can be achieved. Further, the same function as the communication system 10 according to the first embodiment may be embodied by a communication control method, a (computer) program, a non-temporary recording medium on which the program is recorded, or the like. In the communication control method according to one aspect, when transmitting the superimposed signal Si0 from each of the plurality of interfaces 3 in the communication system 10, the timing of transmitting the superimposed signal Si0 is adjusted according to the state of the transmission line 12. The communication system 10 referred to here includes a first system 1, a plurality of interfaces 3, and a plurality of second systems 2. The first system 1 includes one or more first terminals 11 that communicate with each other by the first signal Si1 transmitted through the transmission line 12. The plurality of interfaces 3 are connected to the transmission line 12 and communicate with each other by the superimposed signal Si0 superimposed on the first signal Si1. Each of the plurality of second systems 2 includes one or more second terminals 21 that communicate with each other by a second signal. The plurality of second systems 2 are asynchronous with each other and are connected to the plurality of interfaces 3 in a one-to-one correspondence. Each of the plurality of interfaces 3 transmits the second signal received from the corresponding second system 2 among the plurality of second systems 2 to the other second system 2 via the other interface 3 by the superimposed signal Si0. Forward. The (computer) program according to one aspect is a program for causing a computer system to execute the above-mentioned communication control method.

Hereinafter, modified examples of the first embodiment are listed. The modifications described below can be applied in combination as appropriate.

The communication system 10 in the present disclosure includes a computer system in, for example, an interface 3. The computer system mainly consists of a processor and a memory as hardware. When the processor executes the program recorded in the memory of the computer system, the function as the communication system 10 in the present disclosure is realized. The program may be pre-recorded in the memory of the computer system, may be provided through a telecommunication line, and may be recorded on a non-temporary recording medium such as a memory card, optical disk, hard disk drive, etc. that can be read by the computer system. May be provided. The processor of a computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large scale integrated circuit (LSI). A plurality of electronic circuits may be integrated on one chip, or may be distributed on a plurality of chips. A plurality of chips may be integrated in one device, or may be distributed in a plurality of devices.

Further, for example, a plurality of functions provided in the communication system 10 may be integrated in one housing or may be distributed in a plurality of housings. As an example, a plurality of functions in the interface 3 may be integrated in one housing or may be distributed in a plurality of housings. Further, at least a part of the functions of the communication system 10 may be realized by, for example, a cloud (cloud computing) or the like. Further, in the first embodiment, at least a part of the functions of the communication system 10 distributed in a plurality of devices may be integrated in one housing.

Further, the communication system 10 and the device control system 100 are not limited to facilities such as office buildings, stores, hospitals, schools or factories, and may be introduced into houses such as apartment houses or detached houses, for example.

Further, in the example of FIG. 1, the communication system 10 includes two second systems 2 and two interfaces 3, but the communication system 10 is not limited to this example, and the communication system 10 includes each of the second system 2 and the interface 3. You may have three or more. Similarly, the number of the first terminals 11 in the first system 1, the number of the second terminals 21 in the second system 2, and the number of devices (lighting fixtures 4) to be controlled are not limited to the example of FIG. , Can be changed as appropriate.

Further, the first system 1 is not limited to a system in which a plurality of first terminals 11 communicate with each other via the first terminal 11 as a transmission unit according to a polling selection protocol. For example, the first system 1 may be configured such that a plurality of first terminals 11 directly communicate with each other by the first signal Si1.

Further, each of the plurality of second systems 2 does not have to be a system compliant with the DALI standard, and the communication method of the second terminal 21 is, for example, wireless communication using radio waves as a transmission medium, optical communication, or the like. There may be. When the communication method of the second terminal 21 is wireless communication, the free space for wireless communication becomes the transmission line 22 of the second system 2. Further, each of the plurality of second systems 2 is not limited to a system that controls the device (lighting fixture 4) to be controlled by the device control system 100, and at least a part of the plurality of second systems 2 is, for example, for example. It may be a measurement system, a monitoring system, or the like.

Further, at least a part of the first terminals 11 may have a communication function with the interface 3 by the superimposed signal Si0. In this case, not only the cooperation between the plurality of second systems 2 but also the exchange of data between the first system 1 (the first terminal 11) and the second system 2 (the second terminal 21) is possible. It becomes.

Further, the device control system 100 using the communication system 10 is not limited to the lighting control system, and the control target of the device control system 100 is, for example, an air conditioner, a ventilation fan, an electric shutter, an air purifier, a water heater, a television receiver, and the like. It may be a washing machine, a refrigerator, or the like. Further, the communication system 10 is not essential to be used in the device control system 100 in the first place, and may be used in, for example, a measurement system or a monitoring system.

Further, in the communication system 10, it is not essential that the first system 1 constitutes the main system and each second system 2 constitutes a subsystem. For example, even if each second system 2 constitutes a main system. good.

Further, in the first embodiment, the lighting fixture 4 to be controlled is not included in any of the components of the communication system 10 and the device control system 100, but is not limited to this configuration. That is, the luminaire 4 may be included in any of the components of the communication system 10 and the device control system 100.

(Embodiment 2)
The communication system 10 according to the present embodiment is different from the communication system 10 according to the first embodiment in that each of the plurality of interfaces 3 has a signal filtering function. Hereinafter, the same configurations as those in the first embodiment will be designated by a common reference numeral and description thereof will be omitted as appropriate.

The "filtering function" referred to in the present disclosure refers to at least one of "uplink communication" from the second system 2 to the first system 1 and "downlink communication" from the first system 1 to the second system 2 in the interface 3. , It is a function to pass only a specific telegram. Specifically, the interface 3 passes a telegram from the second system 2 side to the first system 1 side by analyzing the second signal Si2 (see FIG. 9) from the second system 2 for uplink communication. Decide whether or not to let it. Further, for downlink communication, the interface 3 analyzes the superimposed signal Si0 from the first system 1 to determine whether or not to pass the telegram from the first system 1 side to the second system 2 side.

In the present embodiment, whether or not each of the plurality of interfaces 3 transmits the superimposed signal Si0 to the transmission line 12 according to the second signal Si2 received from the corresponding second system 2 among the plurality of second systems 2. It is configured to determine. As an example, the interface 3 determines whether or not to pass a telegram from the second system 2 side to the first system 1 side based on the value of the uplink flag included in the second signal Si2 from the second system 2. For example, if the value of the uplink flag is "1", the interface 3 passes a telegram from the second system 2 side to the first system 1 side, and if the value of the uplink flag is "0", the second system Do not allow the telegram to pass from the 2nd side to the 1st system 1 side.

Further, each of the plurality of interfaces 3 is configured to determine whether or not to transmit the second signal Si2 to each of the plurality of second systems 2 according to the superimposed signal Si0 received from the transmission line 12. There is. As an example, the interface 3 determines whether or not to pass a telegram from the first system 1 side to the second system 2 side based on the value of the downlink flag included in the superimposed signal Si0 from the first system 1. For example, if the value of the downlink flag is "1", the interface 3 passes a telegram from the first system 1 side to the second system 2 side, and if the value of the downlink flag is "0", the first system Do not allow the telegram to pass from the 1st side to the 2nd system 2 side.

In short, in the present embodiment, the interface 3 has a filtering function for passing only a specific message for both uplink communication and downlink communication. The upstream flag is set, for example, at the second terminal 21 which is the transmission source of the message. The downlink flag is set, for example, on the interface 3 which is the source of the superimposed signal Si0.

According to the communication system 10 according to the present embodiment, for example, as shown in FIG. 9, it is possible to pass only a specific message on each interface 3. In the example of FIG. 9, the communication system 10 includes two interfaces 3C, 3D and two second systems 2C, 2D. The second system 2C is connected to the transmission line 12 of the first system 1 via the interface 3C, and the second system 2D is connected to the transmission line 12 of the first system 1 via the interface 3D.

In the example of FIG. 9, the interfaces 3A and 3B determine whether or not to transmit the superimposed signal Si0 to the transmission line 12 according to the second signal Si2 received from the subordinate second systems 2A and 2B, respectively. .. Here, the value of the uplink flag included in the second signal Si2 from the second system 2A is "1", and the value of the uplink flag included in the second signal Si2 from the second system 2A is "0". Suppose. Therefore, when the interface 3A receives the second signal Si2 from the subordinate second system 2A, the interface 3A transmits the superimposed signal Si0 to the transmission line 12. On the other hand, even if the interface 3B receives the second signal Si2 from the subordinate second system 2B, the interface 3B does not transmit the superimposed signal Si0 (shown by a broken line in FIG. 9) to the transmission line 12.

Further, in the example of FIG. 9, the interfaces 3C and 3D determine whether or not to transmit the second signal Si2 to the subordinate second systems 2C and 2D according to the superimposed signal Si0 received from the transmission line 12, respectively. ing. Here, it is assumed that the value of the downlink flag included in the superimposed signal Si0 received by the interface 3C is "1", and the value of the downlink flag included in the superimposed signal Si0 received by the interface 3D is "0". Therefore, when the interface 3C receives the superimposed signal Si0 from the transmission line 12, the interface 3C transmits the second signal Si2 to the subordinate second system 2C. On the other hand, the interface 3D does not transmit the second signal Si2 (shown by the broken line in FIG. 9) to the subordinate second system 2D even if the superimposed signal Si0 is received from the transmission line 12.

According to the communication system 10 of the present embodiment, the increase in the traffic of the first system 1 can be suppressed by the filtering function of the uplink communication, and the increase of the traffic of the second system 2 can be suppressed by the filtering function of the downlink communication. can do. However, it is not an essential configuration for the communication system 10 that the interface 3 has a filtering function for both uplink communication and downlink communication, and the interface 3 has a filtering function for only one of the uplink communication and the downlink communication. You may be.

The configuration (including the modified example) described in the second embodiment can be appropriately combined with various configurations (including the modified example) described in the first embodiment.

(summary)
As described above, the communication system (10) according to the first aspect includes a first system (1), a plurality of interfaces (3), and a plurality of second systems (2). The first system (1) includes one or more first terminals (11) that communicate with each other by a first signal (Si1) transmitted through a transmission line (12). The plurality of interfaces (3) are connected to the transmission line (12) and communicate with each other by the superimposed signal (Si0) superimposed on the first signal (Si1). Each of the plurality of second systems (2) includes one or more second terminals (21) that communicate with each other by a second signal (Si2). The plurality of second systems (2) are asynchronous with each other and are connected to the plurality of interfaces (3) in a one-to-one correspondence. Each of the plurality of interfaces (3) uses a superimposed signal (Si0) to input a second signal (Si2) received from the corresponding second system (2) among the plurality of second systems (2) to another interface. It is configured to transfer to another second system (2) via (3). Each of the plurality of interfaces (3) is configured to adjust the timing of transmitting the superimposed signal (Si0) according to the state of the transmission line (12) when transmitting the superimposed signal (Si0).

According to this aspect, the plurality of second systems (2) are connected to the transmission line (12) of the common first system (1) via the interface (3), respectively. Therefore, by communicating with the plurality of interfaces (3) by the superimposed signal (Si0), data can be exchanged between the plurality of second systems (2). As a result, even when the first system (1) is in operation, by using the superimposed signal (Si0) superimposed on the first signal (Si1) used in the first system (1), the first system can be used. A plurality of second systems (2) can be linked by using a transmission line (12) common to the system (1). Moreover, since each interface (3) adjusts the timing of transmitting the superimposed signal (Si0) to the transmission line (12) according to the state of the transmission line (12), each second system (2) has a communication timing. It becomes possible to communicate with another second system (2) without considering. Therefore, according to the communication system (10), there is an advantage that cooperation between a plurality of second systems (2) can be easily realized.

In the communication system (10) according to the second aspect, in the first aspect, each of the plurality of interfaces (3) collides with the signal transmitted from the other interface (3) with respect to the superimposed signal (Si0). Is generated, the superimposed signal (Si0) is configured to be retransmitted.

According to this aspect, the retransmission of the superimposed signal (Si0) improves the success rate of communication by the superimposed signal (Si0).

In the communication system (10) according to the third aspect, in the second aspect, when each of the plurality of interfaces (3) retransmits the superimposed signal (Si0), after a random waiting time elapses from the occurrence of the collision. It is configured to transmit a superposed signal (Si0).

According to this aspect, since the superimposition signal (Si0) is retransmitted at random timings, collisions between the superimposition signals (Si0) are less likely to occur when the superimposition signal (Si0) is retransmitted.

In the communication system (10) according to the fourth aspect, in any one of the first to third aspects, the first signal (Si1) is a periodic signal. A plurality of time slots (Ts1 to Ts4) set in one frame of the first signal (Si1) are assigned to each of the plurality of interfaces (3). Each of the plurality of interfaces (3) is configured to transmit the superimposed signal (Si0) in the corresponding time slots (Ts1 to Ts4) among the plurality of time slots (Ts1 to Ts4).

According to this aspect, since the transmission timing of the superimposed signal (Si0) is different for each interface (3), the success rate of communication by the superimposed signal (Si0) is improved.

In the communication system (10) according to the fifth aspect, in the fourth aspect, each of the plurality of interfaces (3) has a priority setting unit (39) for receiving priority setting information. A plurality of time slots (Ts1 to Ts4) are assigned to the plurality of interfaces (3) according to their priorities.

According to this aspect, since the order of transmission of the superimposed signal (Si0) in the plurality of interfaces (3) is determined by the priority, the success rate of communication by the superimposed signal (Si0) is improved.

In the communication system (10) according to the sixth aspect, in the fourth or fifth aspect, the plurality of time slots (Ts1 to Ts4) include the first slot and the second slot. The start point of the second slot is located between the start point and the end point of the first slot, and the end point of the first slot is located between the start point and the end point of the second slot.

According to this aspect, since the first slot includes an overlap period overlapping with the second slot, the number of time slots (Ts1 to Ts4) that can be set within a unit time increases.

In the communication system (10) according to the seventh aspect, in the sixth aspect, the interface (3) to which the second slot is assigned among the plurality of interfaces (3) is configured as follows. That is, the interface (3) to which the second slot is assigned is after the start point of the first slot and the start point of the second slot when no signal is transmitted from the other interface (3) to the first slot. Before that, the transmission of the superimposed signal (Si0) is started.

According to this aspect, the interface (3) to which the second slot is assigned accelerates the start of transmission of the superimposed signal (Si0) when the signal is not transmitted from the other interface (3) to the first slot. can.

In the communication system (10) according to the eighth aspect, in the fourth or fifth aspect, each of the plurality of time slots (Ts1 to Ts4) has an overlap period overlapping with the other time slots (Ts1 to Ts4). Not included.

According to this aspect, collisions between superimposed signals (Si0) transmitted from a plurality of interfaces (3) are less likely to occur.

In the communication system (10) according to the ninth aspect, in any one of the first to eighth aspects, each of the plurality of interfaces (3) is at a timing when a signal is not transmitted from the other interface (3). It is configured to transmit a superposed signal (Si0).

According to this aspect, collisions between superimposed signals (Si0) transmitted from a plurality of interfaces (3) are less likely to occur.

In the communication system (10) according to the tenth aspect, in any one of the first to ninth aspects, each of the plurality of interfaces (3) is configured as follows. That is, each of the plurality of interfaces (3) is superimposed on the transmission line (12) according to the second signal (Si2) received from the corresponding second system (2) among the plurality of second systems (2). Determines whether to transmit the signal (Si0).

According to this aspect, it is possible to suppress the unnecessary superimposed signal (Si0) from being transmitted from the interface (3) to the transmission line (12) of the first system (1), and the communication traffic of the first system (1) can be suppressed. Can be suppressed from increasing.

In the communication system (10) according to the eleventh aspect, in any one of the first to tenth aspects, each of the plurality of interfaces (3) is configured as follows. That is, whether each of the plurality of interfaces (3) transmits the second signal (Si2) to each of the plurality of second systems (2) according to the superimposed signal (Si0) received from the transmission line (12). Decide whether or not.

According to this aspect, it is possible to suppress the transmission of an unnecessary second signal (Si2) from the interface (3) to the second system (2), and it is possible to suppress an increase in communication traffic of the second system (2). ..

The device control system (100) according to the twelfth aspect includes a communication system (10) according to any one of the first to eleventh aspects. One or more first terminals (11) include a collective control terminal that collectively controls a plurality of devices, and one or more second terminals (21) are individual controls that individually control a plurality of devices for each device. Including terminals.

According to this aspect, the plurality of second systems (2) are connected to the transmission line (12) of the common first system (1) via the interface (3), respectively. Therefore, by communicating with the plurality of interfaces (3) by the superimposed signal (Si0), data can be exchanged between the plurality of second systems (2). As a result, even when the first system (1) is in operation, by using the superimposed signal (Si0) superimposed on the first signal (Si1) used in the first system (1), the first system can be used. A plurality of second systems (2) can be linked by using a transmission line (12) common to the system (1). Moreover, since each interface (3) adjusts the timing of transmitting the superimposed signal (Si0) to the transmission line (12) according to the state of the transmission line (12), each second system (2) has a communication timing. It becomes possible to communicate with another second system (2) without considering. Therefore, according to the device control system (100), there is an advantage that cooperation between a plurality of second systems (2) can be easily realized. Further, as a whole of the device control system (100), it is possible to achieve both batch control of a plurality of devices by a batch control terminal and individual control of a plurality of devices by an individual control terminal.

In the device control system (100) according to the thirteenth aspect, each of the plurality of devices is a lighting device (4) in the twelfth aspect.

According to this aspect, various control of the luminaire (4) becomes possible.

The communication device according to the fourteenth aspect is used as one of a plurality of interfaces (3) in the communication system (10) according to any one of the first to eleventh aspects.

According to this aspect, the plurality of second systems (2) are connected to the transmission line (12) of the common first system (1) via the interface (3), respectively. Therefore, by communicating with the plurality of interfaces (3) by the superimposed signal (Si0), data can be exchanged between the plurality of second systems (2). As a result, even when the first system (1) is in operation, by using the superimposed signal (Si0) superimposed on the first signal (Si1) used in the first system (1), the first system can be used. A plurality of second systems (2) can be linked by using a transmission line (12) common to the system (1). Moreover, since each interface (3) adjusts the timing of transmitting the superimposed signal (Si0) to the transmission line (12) according to the state of the transmission line (12), each second system (2) has a communication timing. It becomes possible to communicate with another second system (2) without considering. Therefore, according to the communication device (interface 3), there is an advantage that cooperation between a plurality of second systems (2) can be easily realized.

In the communication control method according to the fifteenth aspect, when the superimposed signal (Si0) is transmitted from each of the plurality of interfaces (3) in the communication system (10), the superimposed signal (Si0) is superimposed according to the state of the transmission line (12). Adjust the timing to transmit the signal (Si0). The communication system (10) includes a first system (1), a plurality of interfaces (3), and a plurality of second systems (2). The first system (1) includes one or more first terminals (11) that communicate with each other by a first signal (Si1) transmitted through a transmission line (12). The plurality of interfaces (3) are connected to the transmission line (12) and communicate with each other by the superimposed signal (Si0) superimposed on the first signal (Si1). Each of the plurality of second systems (2) includes one or more second terminals (21) that communicate with each other by a second signal (Si2). The plurality of second systems (2) are asynchronous with each other and are connected to the plurality of interfaces (3) in a one-to-one correspondence. Each of the plurality of interfaces (3) uses a superimposed signal (Si0) to input a second signal (Si2) received from the corresponding second system (2) among the plurality of second systems (2) to another interface. Transfer to another second system (2) via (3).

According to this aspect, the plurality of second systems (2) are connected to the transmission line (12) of the common first system (1) via the interface (3), respectively. Therefore, by communicating with the plurality of interfaces (3) by the superimposed signal (Si0), data can be exchanged between the plurality of second systems (2). As a result, even when the first system (1) is in operation, by using the superimposed signal (Si0) superimposed on the first signal (Si1) used in the first system (1), the first system can be used. A plurality of second systems (2) can be linked by using a transmission line (12) common to the system (1). Moreover, according to the communication control method, when the superimposed signal (Si0) is transmitted from each of the plurality of interfaces (3), the timing at which the superimposed signal (Si0) is transmitted according to the state of the transmission line (12). Is adjusted. Therefore, each second system (2) can communicate with another second system (2) without considering the timing of communication. Therefore, according to the communication control method, there is an advantage that cooperation between a plurality of second systems (2) can be easily realized.

The program according to the sixteenth aspect is a program for causing a computer system to execute the communication control method according to the fifteenth aspect.

According to this aspect, the plurality of second systems (2) are connected to the transmission line (12) of the common first system (1) via the interface (3), respectively. Therefore, by communicating with the plurality of interfaces (3) by the superimposed signal (Si0), data can be exchanged between the plurality of second systems (2). As a result, even when the first system (1) is in operation, by using the superimposed signal (Si0) superimposed on the first signal (Si1) used in the first system (1), the first system can be used. A plurality of second systems (2) can be linked by using a transmission line (12) common to the system (1). Moreover, according to the above program, when transmitting the superimposed signal (Si0) from each of the plurality of interfaces (3), the timing of transmitting the superimposed signal (Si0) according to the state of the transmission line (12) is set. It will be adjusted. Therefore, each second system (2) can communicate with another second system (2) without considering the timing of communication. Therefore, according to the above program, there is an advantage that cooperation between a plurality of second systems (2) can be easily realized.

Not limited to the above aspects, various configurations (including modifications) of the communication system (10) according to the first and second embodiments record a device control system (100), a communication device, a communication control method, a program, or a program. It can be embodied in a non-temporary recording medium or the like.

The configurations according to the second to eleventh aspects are not essential configurations for the communication system (10) and can be omitted as appropriate.

1 1st system 2,2A, 2B, 2C, 2D 2nd system 3,3A, 3B, 3C, 3D interface (communication device)
4,4A, 4B, 4C, 4D Lighting equipment (equipment)
10 Communication system 11, 11A, 11B, 11C, 11D First terminal (collective control terminal)
12 Transmission lines 21,21A, 21B, 21C, 21D, 21E, 21F Second terminal (individual control terminal)
39 Priority setting unit 100 Device control system Si0 Superimposition signal Si1 1st signal Si2 2nd signal Ts1 to Ts4 Time slots (1st slot, 2nd slot)

Claims (18)

A first system that includes one or more first terminals connected to a transmission line,
A plurality of interfaces connected to the transmission line and communicating by superimposed signals,
It is equipped with a plurality of second systems including a plurality of second terminals, each of which communicates by a second signal.
The plurality of second systems are asynchronous with each other and are connected to the plurality of interfaces in a one-to-one correspondence.
Each of the plurality of interfaces transfers the second signal received from the corresponding second system among the plurality of second systems to the other second system via the other interface by the superimposed signal. It is configured as
Each of the plurality of interfaces is configured to adjust the timing of transmitting the superimposed signal according to the state of the transmission line when transmitting the superimposed signal. The communication system according to claim 1, wherein each of the plurality of interfaces is configured to retransmit the superimposed signal when a collision with a signal transmitted from another interface occurs with respect to the superimposed signal. The communication system according to claim 2, wherein each of the plurality of interfaces transmits the superimposed signal after a random waiting time has elapsed from the occurrence of the collision when the superimposed signal is retransmitted. The first signal with which the first terminal communicates is a periodic signal.
A plurality of time slots set in one frame of the first signal are assigned to each of the plurality of interfaces.
The communication system according to any one of claims 1 to 3, wherein each of the plurality of interfaces is configured to transmit the superimposed signal in the corresponding time slot among the plurality of time slots. Each of the plurality of interfaces has a priority setting unit for receiving priority setting information.
The communication system according to claim 4, wherein the plurality of time slots are assigned to the plurality of interfaces according to the priority. The plurality of time slots include a first slot and a second slot.
The fourth or fifth aspect of claim 4 or 5, wherein the start point of the second slot is located between the start point and the end point of the first slot, and the end point of the first slot is located between the start point and the end point of the second slot. Communication system. Of the plurality of interfaces, the interface to which the second slot is assigned is after the start point of the first slot and the second slot when no signal is transmitted from the other interface to the first slot. The communication system according to claim 6, wherein the transmission of the superimposed signal is started before the start point of the above-mentioned. The communication system according to claim 4 or 5, wherein each of the plurality of time slots does not include an overlap period overlapping with the other time slots. The communication system according to any one of claims 1 to 8, wherein each of the plurality of interfaces is configured to transmit the superimposed signal at a timing when a signal is not transmitted from the other interface. Each of the plurality of interfaces determines whether or not to transmit the superimposed signal to the transmission line according to the second signal received from the corresponding second system among the plurality of second systems. The communication system according to any one of claims 1 to 9, which is configured. Each of the plurality of interfaces is configured to determine whether or not to transmit the second signal to each of the plurality of second systems in response to the superimposed signal received from the transmission line. Item 5. The communication system according to any one of Items 1 to 10. The communication system according to any one of claims 1 to 11 is provided.
The one or more first terminals include a batch control terminal that collectively controls a plurality of devices.
The one or more second terminals are device control systems including individual control terminals that individually control the plurality of devices for each device. The device control system according to claim 12, wherein each of the plurality of devices is a lighting device. A communication device used as one of the plurality of interfaces in the communication system according to any one of claims 1 to 11. A first system that includes one or more first terminals connected to a transmission line,
A plurality of interfaces connected to the transmission line and communicating by superimposed signals,
It is equipped with a plurality of second systems including a plurality of second terminals, each of which communicates by a second signal.
The plurality of second systems are asynchronous with each other and are connected to the plurality of interfaces in a one-to-one correspondence.
Each of the plurality of interfaces transfers the second signal received from the corresponding second system among the plurality of second systems to the other second system via the other interface by the superimposed signal. In the communication system
A communication control method for adjusting the timing of transmitting the superimposed signal according to the state of the transmission line when transmitting the superimposed signal from each of the plurality of interfaces. For computer systems
A program for executing the communication control method according to claim 15. A first system that includes one or more first terminals connected to a transmission line,
A plurality of interfaces connected to the transmission line and communicating by superimposed signals,
It comprises a plurality of second systems, each including one or more second terminals that communicate by a second signal.
The plurality of second systems are asynchronous with each other and are connected to the plurality of interfaces in a one-to-one correspondence.
Each of the plurality of interfaces transfers the second signal received from the corresponding second system among the plurality of second systems to the other second system via the other interface by the superimposed signal. It is configured as
Each of the plurality of interfaces is configured to adjust the timing of transmitting the superimposed signal according to the state of the transmission line when transmitting the superimposed signal.
The first signal with which the first terminal communicates is a periodic signal,
A plurality of time slots set in one frame of the first signal are assigned to each of the plurality of interfaces.
Each of the plurality of interfaces is configured to transmit the superimposed signal in the corresponding time slot among the plurality of time slots.
The plurality of time slots include a first slot and a second slot.
The start point of the second slot is located between the start point and the end point of the first slot, and the end point of the first slot is located between the start point and the end point of the second slot.
Communications system. A first system that includes one or more first terminals connected to a transmission line,
A plurality of interfaces connected to the transmission line and communicating by superimposed signals,
It comprises a plurality of second systems, each including one or more second terminals that communicate by a second signal.
The plurality of second systems are asynchronous with each other and are connected to the plurality of interfaces in a one-to-one correspondence.
Each of the plurality of interfaces transfers the second signal received from the corresponding second system among the plurality of second systems to the other second system via the other interface by the superimposed signal. It is configured as
Each of the plurality of interfaces is configured to adjust the timing of transmitting the superimposed signal according to the state of the transmission line when transmitting the superimposed signal.
Each of the plurality of interfaces determines whether or not to transmit the superimposed signal to the transmission line according to the second signal received from the corresponding second system among the plurality of second systems. It is configured
Communications system.

Images