WO2012057147A1 - Communication system and transmission unit - Google Patents

Abstract

A transmission unit is provided with a mediation unit for assigning superimposable time periods to individual protocols such that superimposable time periods used by different groups of superimposed communication terminals for inter-terminal communication are not used for superimposition with different individual protocols. Depending on the assignment of the superimposable time periods, the mediation unit sequentially transmits from the superimposed transmission units communication permissions which permit the superimposed communication terminals of each group to perform inter-terminal communication. The superimposed communication terminals of each group start inter-terminal communication after receiving a communication permission. By this means, the superimposed communication terminals of each group transmit superimposed signals from a signal transmission unit at a timing such that the superimposed signals are superimposed during the respective superimposable time periods assigned by the mediation unit.

Description

Communication system and transmission unit

The present invention comprises a terminal device that communicates using a transmission signal that is repeatedly sent from a transmission unit to a transmission line, and a superimposed communication terminal that communicates using a superimposed signal superimposed on the transmission signal. The present invention relates to a communication system and a transmission unit.

Conventionally, a communication system in which a transmission unit (master unit) and a plurality of terminal devices (slave units) are connected to a transmission path and communication is performed between each terminal device and the transmission unit has been widely used. As an example of this type of communication system, the transmission unit periodically monitors the state of the terminal device, and when there is a change in the state of the terminal device, the transmission unit performs other processing to perform processing corresponding to the state change. There are systems that send signals to terminal devices (see, for example, Japanese Patent No. 1180690, Japanese Patent No. 1195362, and Japanese Patent No. 1144477).

However, in the communication system configured as described above, the terminal devices always communicate with each other via the transmission unit, and the transmission unit polls the terminal device, so the communication speed is low, for example, relatively data such as an analog amount. It is not suitable for transmitting large amounts of information. Further, the above communication system has a problem that the reliability of the system is low because the entire system is stopped when a transmission unit fails.

Therefore, a communication system in which an existing communication system in which terminal devices communicate with each other via a transmission unit and a communication system in which communication terminals directly communicate with each other via peer-to-peer (P2P) has been proposed. (For example, see Japanese Patent Publication No. 2009-225328). In this communication system, since a terminal device that communicates via a transmission unit (base unit) and a superimposed communication terminal that communicates directly with each other share a transmission path, it is possible to easily add a superimposed communication terminal to an existing communication system. be able to. The terminal device performs communication using a transmission signal (first protocol signal) repeatedly sent from the transmission unit to the transmission path, and the superimposed communication terminal uses a superimposed signal (second protocol signal) superimposed on the transmission signal. To communicate.

Here, the transmission signal is a signal of a time division system that is divided into a plurality of periods in the time axis direction for each frame, and a part of the period is assigned as a superimposable period in which the superposed signal can be superposed. That is, the superimposition communication terminal (communication device) analyzes the state of the transmission signal, and sets a transmission path (signal line) common to the transmission signal in the superimposable period (communication adaptation period) assigned to a part of the transmission signal. Communication is performed using a transmitted superimposed signal (packet) (see, for example, International Publication No. 2008/117722).

In this configuration, the superimposition communication terminal divides the transmission data into a plurality of data and sequentially transmits every superimposable period when the amount of transmission data is large and cannot be transmitted within one superimposable period. To do. That is, since transmission data is transmitted over a plurality of superimposable periods, the superimposed communication terminal cannot transmit the transmission data in one frame of the transmission signal if the amount of transmission data increases. The transmission data may be transmitted over a plurality of frames of transmission signals.

By the way, in the communication system having the above-described configuration, it is common for a superimposition communication terminal as a master to poll another superposition communication terminal as a slave and collect measurement data from the superposition communication terminal as a slave. is there. Here, when there are a plurality of superimposition communication terminals as masters in the communication system, each superimposition communication terminal as a master is a superimposition communication terminal as a slave paired with each other by a superimposition signal adopting a unique protocol. Communication will be performed. In this case, since communication between a plurality of sets of superimposed communication terminals is performed during a period in which transmission signals can be superimposed, collision between superimposed signals transmitted from a plurality of superimposed communication terminals as a master occurs, resulting in a communication error. there is a possibility.

Therefore, an object of the present invention is to provide a communication system and a transmission unit in which a communication error is unlikely to occur even when a plurality of sets of superimposed communication terminals communicate with each other using a superimposed signal employing a unique protocol.

The communication system of the present invention employs a transmission unit that repeatedly transmits a transmission signal to a transmission line, a terminal device that communicates using the transmission signal, and a signal that is superimposed on the transmission signal and has its own protocol. A communication system in which a plurality of sets of superimposed communication terminals that perform inter-terminal communication using a superimposed signal are connected to the transmission path, and the transmission signal is divided into a plurality of periods in the time axis direction for each frame. , A time-division type signal in which a part of the period is a superimposable period in which the superposed signal can be superposed and the remaining period is a non-superimposable period that is not used for superimposing the superposed signal, and the transmission units are different The superimposable period is assigned to each of the unique protocols so that the superimposable periods used for the inter-terminal communication between the unique protocols do not overlap. That includes an arbitration unit. In this configuration, since the transmission unit includes an arbitration unit that assigns a superimposable period to each unique protocol, it is possible to avoid overlapping superimposable periods used for inter-terminal communication between different unique protocols. As a result, there is an advantage that communication errors are unlikely to occur even when a plurality of sets of superimposed communication terminals communicate with each other using a superimposed signal employing a unique protocol.

In this communication system, each set of superimposed communication terminals in the plurality of sets of superimposed communication terminals includes a superimposed communication terminal as a master and a superimposed communication terminal as at least one slave, and the superimposed communication terminal as the master. It is desirable to perform inter-terminal communication with the superimposed communication terminal as the slave belonging to the same set using the superimposed signal that employs a unique protocol.

In this communication system, the arbitration unit sequentially transmits a communication permission to each set of superimposed communication terminals in the plurality of sets of superimposed communication terminals according to the allocation of the overlapping possible period. It is desirable to start the inter-terminal communication after receiving permission.

In this communication system, each set of superimposed communication terminals transmits an end notification to the arbitration unit when the inter-terminal communication ends, and the arbitration unit transmits the next communication permission after receiving the end notification. It is more desirable to do.

In this communication system, when the arbitration unit receives an interrupt request from one of the plurality of sets of superimposed communication terminals, the one set of superimposed communication that has issued the interrupt request. It is more desirable to preferentially transmit the communication permission to the terminal.

In this communication system, the arbitration unit transmits allocation information indicating allocation of the superimposable period to the specific protocol to each set of superimposed communication terminals in the multiple sets of superimposed communication terminals, and A synchronization signal for synchronizing between a set of superimposed communication terminals is periodically transmitted, and each set of the superimposed communication terminals is preliminarily received from the arbitration unit according to the allocation information received periodically and the synchronization signal. More preferably, the inter-terminal communication is performed during the superimposable period assigned to each unique protocol.

In this communication system, it is more preferable that the arbitration unit collects communication information related to the inter-terminal communication from the plurality of sets of superimposed communication terminals, and determines allocation of the superimposable period based on the communication information.

In this communication system, the transmission unit converts the superimposed signal of one specific protocol received from one set of the superimposed communication terminals of the plurality of sets of superimposed communication terminals into the superimposed signal of another specific protocol. It is more preferable that a protocol conversion unit for conversion is provided, and the arbitration unit transmits the superimposed signal converted by the protocol conversion unit during the superposition possible period assigned to the other unique protocol.

In this communication system, the protocol conversion unit may convert the superimposition signal of the one specific protocol to the other specific peculiar to which the superimposition possible period is allocated next to the one specific protocol in the arbitration unit. More preferably, it is converted into the superimposed signal of the protocol.

In this communication system, there are three or more types of unique protocols of the superimposed signal, and the transmission unit receives the superimposed signals of a plurality of types of unique protocols received from the plurality of sets of superimposed communication terminals. A protocol conversion unit that converts the superimposition signal of another specific protocol based on the additional information added to the network, and the arbitration unit converts the superimposition signal converted by the protocol conversion unit to the other specific More preferably, it is transmitted during the superimposable period assigned to the protocol.

In this communication system, it is desirable that the additional information includes information indicating a unique protocol as a conversion destination.

The transmission unit of the present invention employs a transmission unit that repeatedly transmits a transmission signal to a transmission line, a terminal device that communicates using the transmission signal, and a signal that is superimposed on the transmission signal and has a unique protocol. Used in a communication system in which a plurality of sets of superimposed communication terminals that perform inter-terminal communication using a superimposed signal are connected to the transmission path, and the transmission signal is divided into a plurality of periods in the time axis direction for each frame. The time-division method signal in which a part of the period is a superimposable period in which the superimposition signal can be superimposed and the remaining period is a non-superimposition period that is not used for superimposition of the superimposition signal. And an arbitration unit that assigns the superimposable period to each of the unique protocols so that the superimposable periods used for the inter-terminal communication do not overlap.

In this transmission unit, a protocol converter that converts the superimposed signal of one specific protocol received from one set of superimposed communication terminals of the plurality of sets of superimposed communication terminals into the superimposed signal of another specific protocol It is preferable that the arbitration unit transmits the superimposition signal converted by the protocol conversion unit during the superimposable period assigned to the other unique protocol.

Preferred embodiments of the invention are described in further detail. Other features and advantages of the present invention will be better understood with reference to the following detailed description and accompanying drawings.
1 is a schematic system configuration diagram of a communication system according to Embodiment 1. FIG. 2 is a schematic block diagram of a transmission unit according to Embodiment 1. FIG. 2 is a schematic block diagram of a superimposed communication terminal according to Embodiment 1. FIG. FIG. 3 is a waveform diagram illustrating a transmission signal according to the first embodiment. 3 is a flowchart showing the operation of the first embodiment. 3 is a time chart showing the operation of the first embodiment. 6 is a time chart showing another operation of the first embodiment. 6 is a time chart showing another operation of the first embodiment. 10 is a flowchart illustrating the operation of the second embodiment. 6 is a time chart showing the operation of the second embodiment. 6 is a schematic block diagram of a transmission unit showing the configuration of Embodiment 3. FIG.

(Embodiment 1)
The communication system of this embodiment is a communication system including a transmission unit 1 connected to a two-wire transmission line 2 as shown in FIG. 1A.

This communication system includes a plurality of terminal devices 301 and 302 connected to the transmission line 2 and communicating with the transmission unit 1 and a plurality of superimposed communication terminals 401, 402, 411 and 412 connected to the transmission line 2 and directly communicating with each other. And. In this communication system, communication is performed using a transmission signal transmitted through the transmission path 2 and a superimposed signal superimposed on the transmission signal. The superimposed signal is a signal having a higher frequency than the transmission signal.

Hereinafter, when the terminal devices 301 and 302 are not distinguished from each other, they are collectively referred to as the terminal device 3, and when the superimposed communication terminals 401, 402, 411, and 412 are not distinguished from each other, they are collectively referred to as the superimposed communication terminal 4. In the example of FIG. 1A, two terminal devices 3 and four superimposed communication terminals 4 are connected to the transmission path 2, but three or more terminal devices 3 and five or more superimposed communication terminals 4 are connected. Also good.

The plurality of terminal devices 3 are connected in parallel to the transmission unit 1 via the transmission path 2. The transmission unit 1 and the terminal device 3 are time-division multiplex transmission systems (hereinafter referred to as “basic systems”) in which data transmission from the transmission unit 1 to the terminal device 3 and data transmission from the terminal device 3 to the transmission unit 1 are performed in a time division manner. ”).

In the basic system, the terminal device 3 is classified into two types: a monitoring terminal provided with a switch and a sensor (not shown) and a control terminal provided with a load (not shown). As a result, it is possible to control the load attached to the control terminal according to the monitoring input from the switch or sensor attached to the monitoring terminal. Here, the terminal device 3 stores its own pre-assigned address in a storage unit (not shown).

When the monitoring terminal receives the monitoring input, it transmits control information corresponding to the monitoring input to the transmission unit 1. When receiving the control information, the transmission unit 1 transmits the control information to the control terminal associated with the monitoring terminal by the address. Upon receiving the control information, the control terminal controls the load according to the control information. Since the control information reflects the monitoring input of the switch or the like, the monitoring input of the switch or the like is eventually reflected in the load control.

The transmission unit 1 transmits to the transmission line 2 a time-division transmission signal composed of voltage waveforms in a format divided into a plurality of periods in the time axis direction as shown in FIG. That is, the transmission signal is a bipolar signal (±) comprising a preliminary interruption period 31, a preliminary period 32, a transmission period 33, a return period 34, an interruption period 35, a short-circuit detection period 36, and a pause period 37. 24V) time division multiplexed signal. The preliminary interruption period 31 is a period for detecting a secondary interruption, the preliminary period 32 is a period set in accordance with the interruption period 35 and the short-circuit detection period 36, and the transmission period 33 is for transmitting data to the terminal device 3. It is a period for transmission. The return period 34 is a time slot for receiving a return signal from the terminal device 3, the interrupt period 35 is a period for detecting an interrupt signal described later, and the short circuit detection period 36 is a period for detecting a short circuit. It is. The pause period 37 is a period for when processing is not in time. The transmission signal is a signal for transmitting data by modulating a carrier composed of a pulse train.

As illustrated in FIG. 1B, the transmission unit 1 includes a transmission unit 11 and a reception unit 12 connected to the transmission path 2, and a transmission processing unit 13 connected to the transmission unit 11 and the reception unit 12. The transmission unit 11 transmits a transmission signal, and the reception unit 12 receives data returned during the transmission signal return period 34, detects a secondary interrupt during the preliminary interruption period 31, 35, an interrupt signal is detected. The transmission processing unit 13 performs various processes on data transmitted and received by the transmission unit 11 and the reception unit 12.

Subsequently, the operation of the basic system will be described.

In each terminal device 3, when the address data included in the transmission period 33 of the transmission signal received via the transmission path 2 matches the address stored in each storage unit (not shown), the load is reduced from the transmission signal. Capture control information for control. Further, the terminal device 3 returns the control information as a current mode signal (a signal transmitted by short-circuiting the transmission line 2 via an appropriate low impedance) in synchronization with the transmission signal return period 34. In addition, the power supply of the internal circuit of the terminal device 3 is supplied by rectifying and stabilizing the transmission signal transmitted through the transmission path 2.

The transmission unit 1 always performs polling for sequentially accessing the terminal device 3 by cyclically changing the address data included in the transmission signal. At the time of constant polling, the terminal device 3 whose address data included in the transmission signal matches its own address operates if the control information is included in the transmission signal. Return to the transmission unit 1.

Further, when the transmission unit 1 receives an interrupt signal generated in response to a monitoring input such as a switch in any of the monitoring terminals (terminal device 3), the transmission unit 1 searches for the terminal device 3 that generated the interrupt signal, The terminal device 3 is accessed to perform interrupt polling.

That is, the transmission unit 1 always transmits a transmission signal in which the mode data is in the normal mode, and detects an interrupt signal generated in the monitoring terminal (terminal device 3) in synchronization with the transmission signal interrupt period 35. The transmission signal in which the mode data is set to the interrupt polling mode is transmitted.

If the upper bit of the address data of the transmission signal in the interrupt polling mode matches the upper bit of its own address, the terminal device 3 that has generated the interrupt signal synchronizes itself with the return period 34 of the transmission signal. The lower bits of the address of are returned as return data. As a result, the transmission unit 1 can acquire the address of the terminal device 3 that generated the interrupt signal.

When the address of the terminal device 3 that generated the interrupt signal is acquired by the transmission unit 1, the transmission unit 1 sends a transmission signal requesting the terminal device 3 to return control information, and the terminal device 3 The control information corresponding to the monitoring input such as is returned to the transmission unit 1. When receiving the control information, the transmission unit 1 gives an instruction to clear the monitoring input of the corresponding terminal device 3, and the terminal device 3 returns clearing of the monitoring input.

The transmission unit 1 that has received the control information transmits the control information to be transmitted to the terminal device (control terminal device) 3 that is associated with the terminal device (monitoring terminal device) 3 that is the transmission source of the control information by the correspondence relationship of the address. Generate. The transmission unit 1 sends a transmission signal including this control information to the transmission line 2 to control the load attached to the terminal device (control terminal device) 3.

As described above, in the basic system, the terminal devices (monitoring terminal unit, control terminal unit) 3 communicate with each other via the transmission unit 1 in accordance with a polling / selecting protocol.

By the way, in the communication system according to the present embodiment, a plurality of superimposed communication terminals 4 communicate with each other using the superimposed signal superimposed on the transmission signal while sharing the transmission path 2 with the basic system.

In the present embodiment, among the plurality of superimposed communication terminals 401, 402, 411, 412 connected to the transmission path 2, the superimposed communication terminals 401, 411 function as a master, and the remaining superimposed communication terminals 402, 412 Functions as a slave. Superimposition communication terminal 401 as a master and superposition communication terminal 402 as a slave form a pair, and communicate with each other by a superposition signal according to a first protocol. On the other hand, superimposition communication terminal 411 as a master and superposition communication terminal 412 as a slave form a pair, and communicate with each other by a superimposition signal according to a second protocol different from the first protocol. In the following, communication performed by each set of superimposed communication terminals 4 using a superimposed signal of a unique protocol (first protocol or second protocol) is referred to as inter-terminal communication.

Each of the superposition communication terminals 401 and 411 as a master performs polling by transmitting a superposition signal to the superposition communication terminals 402 and 412 as a slave that forms a pair with each of the superposition communication terminals 402 and 412. Get the data from each. A plurality of superimposed communication terminals as slaves that form a pair with each of the superimposed communication terminals 401 and 411 as masters may be provided. In this case, each of the superimposed communication terminals 401 and 411 sequentially polls the superimposed communication terminal as a slave that forms a pair with each.

Here, the monitoring device 6 is connected to the superimposed communication terminals 401 and 411 as masters, and the monitored device 7 is connected to the superimposed communication terminals 402 and 412 as slaves. The monitored device 7 outputs monitoring information transmitted between the superimposed communication terminals 4 to the superimposed communication terminals 402 and 412, and the monitoring device 6 acquires the monitoring information from the superimposed communication terminals 401 and 411. The monitored device 7 and the monitoring device 6 exchange data with the superimposed communication terminal 4 by performing regular communication.

That is, it is the superimposed communication terminal 4 that performs communication (communication between terminals) via the transmission path 2, but the monitored device 7 generates data to be transmitted (monitoring information). It is the monitoring device 6 that processes. Here, the superimposition communication terminal 4 functions as an adapter that performs communication by converting data from the monitored device 7 or the monitoring device 6 connected thereto and transmitting the data on the transmission path 2. The monitoring information output from the monitored device 7 includes, for example, information such as power consumption, temperature and humidity of the electric device. Here, the monitored device 7 connected to the superimposed communication terminal 402 measures power consumption, the monitored device 7 connected to the superimposed communication terminal 412 measures temperature / humidity, and each measurement result is monitored information. To the monitoring device 6 via the superimposed communication terminal 4.

As shown in FIG. 1C, the superimposed communication terminal 4 includes a signal sending unit 41 and a signal receiving unit 42 connected to the transmission line 2, a processing unit 43 connected to the signal sending unit 41 and the signal receiving unit 42, and a processing And an interface unit 44 connected to the unit 43. The signal sending unit 41 sends a superimposed signal, and the signal receiving unit 42 receives the superimposed signal. The interface unit 44 is connected to the monitoring device 6 or the monitored device 7.

In the superposition communication terminals 402 and 412 as slaves, the processing unit 43 acquires monitoring information from the monitored device 7 via the interface unit 44, and sends this monitoring information from the signal sending unit 41 to the transmission path 2 by a superposition signal. To do. In the superimposed communication terminals 401 and 411 as masters, the processing unit 43 acquires monitoring information from the superimposed signal received by the signal receiving unit 42, and outputs the monitoring information to the monitoring device 6 via the interface unit 44.

Specifically, the superimposition communication terminal 4 sends a packet including data to be transmitted to the other superimposition communication terminal 4 to the transmission path 2 and receives a packet transmitted by the other superimposition communication terminal 4. Packets transmitted and received between the superimposed communication terminals 4 are superimposed on the transmission signal transmitted from the transmission unit 1. In short, communication between the terminal devices 3 is performed via the transmission unit 1, whereas communication between terminals of the superimposed communication terminals 4 is directly performed between the superimposed communication terminals 4 without passing through the transmission unit 1. Therefore, the inter-terminal communication between the superimposed communication terminals 4 can increase the communication speed compared to the communication between the terminal apparatuses 3, and can transmit information having a relatively large amount of data such as an analog amount (power consumption, for example). Is suitable.

The superimposition communication terminal 4 includes a signal monitoring unit 45 (see FIG. 1C) that monitors a transmission signal transmitted between the transmission unit 1 and the terminal device 3 of the basic system. Analyzes the data transmission status (hereinafter referred to as “state”). The signal transmission unit 41 has a function of determining whether or not the state analyzed by the signal monitoring unit 45 is in a state suitable for superimposition of the superimposed signal, and transmitting a superimposed signal at a timing determined to be suitable for transmission. It has.

Here, the transmission signal adopts a signal format as shown in FIG. In the preliminary interruption period 31, the preliminary period 32, and the pause period 37, even if the superimposed signal is superimposed, the communication by the transmission signal is not affected, and the inter-terminal communication by the superimposed signal is not easily influenced by the transmission signal. This is a period in which superimposition is possible (hereinafter referred to as “superimposable period”).

In other periods (transmission period 33, return period 34, interrupt period 35, and short circuit detection period 36), the time during which the transmission signal is stable at the high level or the low level is relatively short, and the superimposed signal is superimposed. It is easy to affect the communication by the transmission signal. In addition, when the superimposed signal is superimposed in the other period, inter-terminal communication using the superimposed signal is easily affected by a signal (interrupt signal or return data) transmitted / received between the transmission unit 1 and the terminal device 3. Therefore, the other period is a period that is not used for superimposing the superimposed signal (hereinafter referred to as “non-superimposed period”).

Also, the rising and falling periods of the transmission signal are not suitable for superimposing the superimposed signal due to the influence of harmonic noise or the transient response accompanying the signal voltage inversion. Therefore, the transmission signal becomes a non-superimposable period for a predetermined time (for example, 300 μs) after the switching (rising or falling) of the period among the preliminary interruption period 31, the preliminary period 32, and the pause period 37.

Therefore, the signal transmission unit 41 is configured to determine whether it is a superimposable period or a non-superimposable period based on the analysis result of the state of the transmission signal, and transmit a superimposition signal only when it is determined as a superimposable period. ing. The superimposition communication terminal 4 thus synchronizes with the transmission signal and superimposes the superimposition signal only during the period in which the transmission signal can be superimposed, thereby performing communication by the transmission signal using the common transmission path 2 and inter-terminal communication by the superimposition signal. To avoid interference.

Here, when the amount of transmission data is large and transmission is not possible within one superimposable period, the superimposition communication terminal 4 interrupts inter-terminal communication at the end of the superimposition possible period, and next time The remaining data is transmitted during the superimposable period.

In addition, the power supply to each part of the superimposition communication terminal 4 is supplied by rectifying and stabilizing the transmission signal transmitted from the transmission unit 1 via the transmission line 2 as in the terminal device 3 of the basic system. (Concentrated power supply method). However, the power supply to each part of the superimposed communication terminal 4 is not limited to this configuration, and may be performed by a system (local power supply system) that is supplied by rectifying and stabilizing commercial power.

Incidentally, in the communication system of the present embodiment, there are a plurality of superposition communication terminals 401 and 411 as masters. Therefore, each of the superimposed communication terminals 401 and 411 serving as the master performs inter-terminal communication with the superimposed communication terminals 402 and 412 serving as the slaves that are paired with each other by using a superimposed signal that employs a unique protocol. The unique protocol of each set of superimposed communication terminals 4 used for sending and receiving superimposed signals is stored in advance in the storage unit 46 (see FIG. 1C) of each superimposed communication terminal 4.

However, when a plurality of sets of superimposed communication terminals 4 having different protocols perform inter-terminal communication independently, when the overlapping possible periods used by the superimposed signals having different protocols overlap, collision between the superimposed signals may occur. May occur and result in a communication error.

Therefore, in the present embodiment, as illustrated in FIG. 1B, the arbitration unit 14 that assigns a superimposable period to each protocol so that the transmission unit 1 does not overlap the superimposable periods used for inter-terminal communication between different protocols. It has. Further, the transmission unit 1 includes a superimposition transmission unit 15 that is connected to the transmission path 2 and transmits a superimposition signal, and a superimposition reception unit 16 that is connected to the transmission path 2 and receives the superimposition signal. The arbitration unit 14 is connected to the superimposition transmission unit 15, the superimposition reception unit 16, and the transmission processing unit 13.

Here, each superimposition communication terminal 4 transmits a superimposition signal from the signal transmission unit 41 at a timing such that the superimposition signal is superimposed in the superimposable period assigned to the unique protocol by the arbitration unit 14. In short, each superimposition communication terminal 4 performs superimposition of the protocol superimposition signals stored in the respective storage units 46 during the superimposition possible period assigned by the arbitration unit 14.

Hereinafter, a method for assigning a superimposable period by the arbitrating unit 14 will be described in more detail.

The arbitration unit 14 assigns a superimposable period (preliminary interrupt period 31, preliminary period 32, and pause period 37) used for superimposition of the superimposed signal in units of one frame of the transmission signal. Here, the transmission signal has one frame from the preliminary interruption period 31 to the pause period 37. In the present embodiment, an example is shown in which the arbitrating unit 14 alternately assigns a superimposable period to the first protocol and the second protocol.

The arbitration unit 14 sequentially transmits, from the superimposition transmission unit 15, communication permission for permitting inter-terminal communication to each set of superimposition communication terminals 4 according to the allocation of the superimposable period. Superimposition communication terminal 4 starts communication between terminals after receiving communication permission. That is, the superimposed communication terminal 4 does not perform inter-terminal communication until communication permission is issued from the arbitrating unit 14.

More specifically, the communication system of the present embodiment operates according to the flowchart of FIG. That is, when the communication system is activated (S1), the arbitration unit 14 first issues a communication permission that permits inter-terminal communication using the superimposed signal of the first protocol to the superimposed communication terminals 401 and 402 (S2). The superimposed communication terminals 401 and 402 that have received the communication permission transmit a start notification to the arbitrating unit 14 (S4) when performing inter-terminal communication using the superimposed signal of the first protocol (S3: Yes). Communication is started (S5). Superimposition communication terminals 401 and 402 transmit an end notification to arbitration unit 14 when the inter-terminal communication ends (S6).

Upon receiving the end notification from the superimposition communication terminals 401 and 402, the arbitration unit 14 gives the next communication permission, that is, communication permission that permits inter-terminal communication using the superimposition signal of the second protocol to the superimposition communication terminals 411 and 412. In response to this (S7). Also, when the superimposed communication terminals 401 and 402 do not perform inter-terminal communication using the superimposed signal of the first protocol (S3: No), that is, when the start notification is not returned from the superimposed communication terminals 401 and 402. The arbitration unit 14 issues communication permission to the superimposed communication terminals 411 and 412 (S7).

The superimposed communication terminals 411 and 412 that have received the communication permission transmit a start notification to the arbitration unit 14 (S9) when performing inter-terminal communication using the superimposed signal of the second protocol (S8: Yes). Communication is started (S10). Superimposition communication terminals 411 and 412 transmit an end notification to arbitration unit 14 when the inter-terminal communication ends (S11). Upon receiving the end notification from the superimposed communication terminals 411 and 412, the arbitration unit 14 returns to the next communication permission, that is, the process S <b> 2 for issuing the communication permission to the superimposed communication terminals 401 and 402. Also, when the superimposed communication terminals 411 and 412 do not perform inter-terminal communication using the superimposed signal of the second protocol (S8: No), that is, when there is no start notification reply from the superimposed communication terminals 411 and 412. The arbitrating unit 14 returns to the process S2.

Note that the exchange of communication permission, start notification, and end notification between the transmission unit 1 and the superimposition communication terminal 4 is performed between the superimposition transmission unit 15 and the signal reception unit 42, or between the superimposition reception unit 16 and the signal transmission unit 41. The transmission signal is superposed during the period in which the transmission signal can be superposed. The exchange between the transmission unit 1 and the superimposed communication terminal 4 may be performed using a superimposed signal of a protocol unique to each superimposed communication terminal 4 or a protocol common to all the superimposed communication terminals 4 in the communication system. This may be done using the superposition signal.

As described above, when the arbitrating unit 14 alternately assigns the superimposable period to the first protocol and the second protocol, the relationship between the transmission signal and the superposed signal is as shown in FIG. 4, for example. In FIG. 4, the signal waveform of the transmission signal is shown in the upper stage, and the content of the superimposed signal superimposed on the transmission signal is shown in the lower stage.

In the example of FIG. 4, in the first frame F1 of the transmission signal, communication permission for permitting communication between terminals of the first protocol is performed from the arbitration unit 14, and communication between terminals of the first protocol is performed in the second frame F2. A start notification indicating the start of is performed. The superimposed communication terminals 401 and 402 perform inter-terminal communication using the superimposed signal of the first protocol during the period in which the third and fourth frames F3 and F4 can be superimposed, and the fifth frame F5 includes the first protocol. An end notification indicating the end of inter-terminal communication is transmitted.

In the sixth frame F6 of the transmission signal of FIG. 4, the arbitration unit 14 grants communication permission to permit communication between terminals of the second protocol, and in the seventh frame F7, start of communication between terminals of the second protocol. A start notification representing is given. The superimposed communication terminals 411 and 412 perform inter-terminal communication using the superimposed signal of the second protocol during the superimposable period of the eighth frame F8, and end of the inter-terminal communication of the second protocol in the ninth frame F9. An end notification indicating that is sent. Therefore, in the next tenth frame F10, communication permission for permitting communication between terminals of the first protocol is performed from the arbitration unit 14.

However, in the example of FIG. 4, in the 11th frame F11, there is no reply of the start notification indicating the start of communication between terminals of the first protocol. For this reason, the arbitrating unit 14 grants communication permission for allowing communication between terminals of the second protocol to the twelfth frame F12. As described above, in the example of FIG. 4, superposition communication terminals 401 and 402 that perform inter-terminal communication using the superimposition signal of the first protocol and superposition communication that performs inter-terminal communication using the superposition signal of the second protocol. Opportunities for inter-terminal communication are alternately given to the terminals 411 and 412.

Note that the exchange of the communication permission, the start notification, and the end notification between the transmission unit 1 and the superimposed communication terminal 4 may be performed exclusively using one frame of the transmission signal, as in the example of FIG. You may perform using only a part of superimposable period in 1 frame. In the latter case, the superimposition communication terminal 4 can also perform inter-terminal communication during a vacant superimposable period even within the same frame as the exchange of communication permission, start notification, and end notification.

Here, in the present embodiment, the arbitrating unit 14 automatically adjusts according to the number of superposed communication terminals 4 having different protocols so that opportunities for inter-terminal communication using the superimposed signals of the respective protocols are given substantially equally. The allocation of the period that can be superimposed on is determined. That is, the arbitrating unit 14 acquires in advance the protocols used by the superimposition communication terminal 4 connected to the transmission path 2 and assigns the superimposable periods to these protocols so that the superimposable periods are allocated approximately equally. decide. For example, when the superimposition communication terminal 4 that performs inter-terminal communication using the superimposition signal of the third protocol in addition to the first and second protocols is provided, the arbitration unit 4 includes the first protocol, the second protocol, Communication permission is issued in the order of protocol 2 and protocol 3, and an opportunity for communication between terminals is given.

According to the communication system having the above-described configuration, the transmission unit 1 includes the arbitration unit 14 that assigns each superimposable period to each protocol, so that it is possible to avoid overlapping the superimposable periods used between the superimposed signals. . That is, while a plurality of sets of superposition communication terminals 4 perform inter-terminal communication using a superposition signal that employs a unique protocol, inter-terminal communication of each protocol is performed during the superposition possible period assigned by the arbitration unit 14. As a result, collision between superimposed signals can be avoided. Therefore, the above communication system has an advantage that communication errors are unlikely to occur even when a plurality of sets of superimposed communication terminals 4 communicate with each other using a superimposed signal employing a unique protocol.

In addition, since the transmission unit 1 assigns the superimposable period in a centralized manner in the arbitration unit 14, even if the types of protocols used in the communication system increase, the superimposable period is different between different protocols. It is easy to assign a superimposable period so as not to overlap. For this reason, in the present embodiment, a communication system in which superimposed signals of two types of protocols, the first protocol and the second protocol, are mixed is illustrated, but not limited to this example, superimposed signals of three or more types of protocols are included. Even in a mixed communication system, the occurrence of collision can be reliably avoided.

Furthermore, since the arbitration unit 14 sequentially transmits communication permission to each set of superimposed communication terminals 4 according to the allocation of the superimposable period, the superimposed communication terminal 4 starts inter-terminal communication after receiving this communication permission. Thus, collision between superimposed signals can be avoided. That is, the superimposition communication terminal 4 shifts the timing of inter-terminal communication with another set of superimposition communication terminals 4 with a relatively simple configuration that only performs inter-terminal communication according to the communication permission sequentially transmitted from the arbitration unit 14. be able to.

Further, since the arbitration unit 14 transmits the next communication permission after receiving the end notification indicating the end of the inter-terminal communication from the superimposition communication terminal 4, even if the time required for the inter-terminal communication differs for each protocol, The next communication permission can be issued after the end-to-end communication is completed. Therefore, it is possible to reliably avoid the collision between the superimposed signals while suppressing the time interval between the communication between terminals of the first protocol and the communication between terminals of the second protocol short. Furthermore, the arbitration unit 14 does not perform inter-terminal communication because it transmits the next communication permission even when there is no reply to the start notification indicating the start of inter-terminal communication from the superimposed communication terminal 4 that has issued the communication permission. The superimposition communication terminal 4 can be skipped and the superimposition possible period can be allocated effectively.

By the way, when the arbitration unit 14 receives an interrupt request from the superimposition communication terminal 4, the communication permission to the superimposition communication terminal 4 that has issued the interrupt request has priority over the communication permission to other superimposition communication terminals 4. Then, an interrupt function may be added so as to transmit. Hereinafter, the operation of the arbitration unit 14 to which the interrupt function is added will be described with reference to examples of FIGS. 5A and 5B.

In this example, as shown in FIG. 5A, the arbitrating unit 14 originally assigns a transmission signal superimposable period alternately to the first protocol and the second protocol every three frames. Here, in the example of FIG. 5A, two superposition communication terminals as slaves that form a pair with each of superposition communication terminals 401 and 411 as masters are provided, and each superposition communication terminal 401 and 411 forms a pair with each other. Polling is sequentially performed on the superimposed communication terminals as slaves. Note that, hereinafter, the superimposed communication terminals as two slaves that form a pair with the superimposed communication terminal 401 as a master are referred to as first and second slaves (not shown), and form a pair with the superimposed communication terminal 411 as a master. The superposition communication terminal as two slaves will be described as third and fourth slaves (not shown).

That is, the superimposition communication terminal 401 performs inter-terminal communication with the first slave in the first to third, thirteenth to fifteenth frames F1 to F3, and F13 to F15 among the superposition communication terminals assigned to the first protocol. In the seventh to ninth frames F7 to F9, terminal-to-terminal communication is performed with the second slave. The superimposed communication terminal 411 performs inter-terminal communication with the third slave in the fourth to sixth frames F4 to F6 among the superimposed communication terminals assigned to the second protocol, and in the tenth to twelfth frames F10 to F12. Inter-terminal communication is performed with the fourth slave.

In FIG. 5B, an interrupt request is received from the second slave that forms a pair with the superimposed communication terminal 401 in the third frame F3 in which the superimposed communication terminal 401 and the first slave are communicating with each other in the example of FIG. 5A. An example is shown below. Here, the interrupt request is made by a superimposed signal superimposed in the transmission signal interruption period 35, and includes at least an identifier (address) for the arbitrating unit 14 to identify the superimposed communication terminal 4 that is the transmission source. Yes. In FIG. 5B, the superimposed signal superimposed on the transmission signal is indicated by “P”.

When there is an interrupt request from the second slave in the third frame as shown in FIG. 5B, the arbitration unit 14 permits communication between terminals in the first protocol in the next frame (fourth frame F4). Put out. In short, the arbitration unit 14 originally gives the superimposition communication terminal 4 a communication permission that permits inter-terminal communication using the superimposition signal of the second protocol in the fourth frame F4. The communication permission which permits the communication between terminals using the superimposed signal is issued.

Thus, the second slave that has issued the interrupt request can communicate with the superimposed communication terminal 401 as the master from the fourth frame F4 onward. After the superimposition communication terminal 401 and the second slave perform inter-terminal communication in the fourth to sixth frames F4 to F6, the arbitration unit 14 assigns the superimposable period from the state before the interrupt request is issued. Resume. That is, in the seventh to ninth frames F7 to F9, the superimposed communication terminal 411 performs inter-terminal communication with the third slave, and in the tenth to twelfth frames F10 to F12, the superimposed communication terminal 401 and the second slave. Perform terminal-to-terminal communication.

As described above, according to the configuration in which the interrupt function is added to the arbitration unit 14, the superimposition communication terminal 4 normally performs interrupts while sequentially performing inter-terminal communication according to the allocation determined by the arbitration unit 14. By issuing a request, communication permission can be obtained preferentially. Thereby, the superimposition communication terminal 4 performs inter-terminal communication by preferentially transmitting communication permission from the arbitration unit 14 when, for example, some event occurs and it is necessary to perform inter-terminal communication immediately. It becomes possible.

(Embodiment 2)
The communication system according to the present embodiment is different from the communication system according to the first embodiment in the method of assigning a superimposable period by the arbitrating unit 14.

That is, in the first embodiment, the arbitration unit 14 sequentially transmits and assigns communication permission to the superimposed communication terminal 4, whereas in the present embodiment, the arbitration unit 14 indicates allocation of a superimposable period to the superimposed communication terminal 4. Allocation is performed by transmitting allocation information to the superimposed communication terminal 4 in advance.

In the present embodiment, the arbitration unit 14 determines assignment of a superimposable period to each protocol in a predetermined setting period after activation of the communication system, and transmits assignment information indicating this assignment to all the superposition communication terminals 4. The allocation information here is information indicating allocation of a superimposable period to a protocol specific to at least the superimposition communication terminal 4 that is the transmission destination of the information, and is superimposed on all protocols including the transmission destination of the information Information representing allocation of possible periods may be used. The superimposed communication terminal 4 stores the received allocation information in the storage unit 46.

Further, the arbitration unit 14 periodically transmits a synchronization signal for synchronizing all the superimposed communication terminals 4 in the communication system. The superimposition communication terminal 4 can identify the timing of the superimposable period allocated to each unique protocol according to the allocation information received in advance by synchronizing with the synchronization signal. I do. Note that the exchange of the allocation information and the synchronization signal between the transmission unit 1 and the superimposition communication terminal 4 is performed between the superimposition transmission unit 15 and the signal reception unit 42 using the superimposition signal during the period in which the transmission signal can be superimposed. Is called.

Further, in the first embodiment, the arbitration unit 14 determines the assignment so that the opportunities of communication between terminals using the superimposed signals of the respective protocols are given substantially evenly, whereas in the present embodiment, the arbitration unit 14 performs the superimposition. The allocation is determined by communicating with the communication terminal 4.

In the present embodiment, the arbitrating unit 14 automatically determines allocation of a superimposable period based on communication information collected from the superimposed communication terminal 4 through communication with the superimposed communication terminal 4. The communication information here is information related to inter-terminal communication in accordance with a protocol specific to each set of superposition communication terminals 4, and for example, the amount of data exchanged between the superposition communication terminals 4 by inter-terminal communication, and the inter-terminal communication There is a frequency.

Note that communication information is exchanged between the transmission unit 1 and the superimposed communication terminal 4 between the superimposed transmission unit 15 and the signal reception unit 42 or between the superimposed reception unit 16 and the signal transmission unit 41. The superposition signal is used during the superposition possible period.

The arbitration unit 14 communicates with each superimposition communication terminal 4 in the communication system and collects communication information during the superimposable period of the first frame of the transmission signal transmitted after the communication system is activated. Here, the arbitrating unit 14 determines allocation of a superimposable period based on the amount of data transmitted and received by each set of superimposition communication terminals 4 using a superimposition signal of a unique protocol. In other words, the arbitration unit 14 can collect communication information including data amounts that are transmitted and received by each set of superimposed communication terminals 4 using superimposed signals of a unique protocol, and can superimpose according to the relative relationship of the data amounts. Determine the period assignment. Specifically, the arbitrating unit 14 compares the data amount exchanged between the superimposed communication terminals 401 and 402 with the data amount exchanged between the superimposed communication terminals 411 and 412, and superimposes according to the comparison result. Determine allocation of possible periods.

The amount of data exchanged between superimposed communication terminals 401 and 402 using the superimposed signal of the first protocol is larger than the amount of data exchanged between superimposed communication terminals 411 and 412 using the superimposed signal of the second protocol. The case where there are few is shown as an example. In this case, the arbitrating unit 14 determines allocation of the superimposable period so that a relatively long superimposable period is preferentially allocated to the second protocol having a large amount of data. As a result, the superimposition communication terminal 4 can perform communication using the superimposition signal in a superimposition possible period having a length suitable for the amount of data to be transmitted and received, thereby enabling smooth data transmission as a whole communication system.

As another example, the arbitration unit 14 is configured to determine allocation of a superimposable period based on the frequency with which each set of superimposition communication terminals 4 performs communication using a superimposition signal of a unique protocol. May be. In other words, the arbitration unit 14 collects communication information including the frequency with which each set of superimposed communication terminals 4 communicates using a superimposed signal of a unique protocol, and the superimposable period according to the relative relationship of the communication frequency. Determine the assignment. Specifically, the arbitrating unit 14 compares the frequency at which communication is performed between the superimposed communication terminals 401 and 402 with the frequency at which communication is performed between the superimposed communication terminals 411 and 412, and performs superimposition according to the comparison result. Determine allocation of possible periods.

Communication using the superimposed signal of the first protocol between the superimposed communication terminals 401 and 402 is performed at intervals of 1 minute, and communication using the superimposed signal of the second protocol between the superimposed communication terminals 411 and 412 is performed at an interval of 1 hour. An example is given in In this case, the arbitrating unit 14 determines assignment of the superimposable period so that the superimposable period is preferentially assigned to the first protocol having a high communication frequency. As a result, the superimposition communication terminal 4 can perform communication using the superimposition signal during the superimposition possible period at a timing suitable for each communication frequency, and the entire communication system can perform smooth data transmission.

More specifically, the communication system of this embodiment operates according to the flowchart of FIG. That is, when the communication system is activated (S21), the arbitrating unit 14 communicates with the superimposed communication terminals 401 and 402 during the set period, and acquires communication information related to inter-terminal communication of the first protocol (S22). Further, the arbitrating unit 14 communicates with the superimposed communication terminals 411 and 412 and acquires communication information related to inter-terminal communication of the second protocol (S23).

Then, based on the collected communication information, the arbitration unit 14 determines the time and timing allocated to each protocol per unit time, and generates allocation information (S24). When the allocation is determined, the arbitration unit 14 transmits the generated allocation information to the superimposed communication terminals 401 and 402 that perform the inter-terminal communication of the first protocol (S25), and further superimpose communication that performs the inter-terminal communication of the second protocol. The allocation information is transmitted to the terminals 411 and 412 (S26).

Thereafter, when the set period ends, the arbitration unit 14 starts transmission of a synchronization signal periodically (S27). The superposition communication terminal 4 performs inter-terminal communication during the superposition possible period assigned to each unique protocol according to the assignment information received in advance from the arbitration unit 14 and the synchronization signal periodically received (S28).

As described above, when the arbitrating unit 14 assigns the superimposable period to the first protocol and the second protocol, the relationship between the transmission signal and the superposed signal is as shown in FIG. In FIG. 7, the signal waveform of the transmission signal is shown in the upper stage, and the content of the superimposed signal superimposed on the transmission signal is shown in the lower stage.

In FIG. 7, the transmission unit 1 has a frame period T0 of 20 ms, and can transmit 15 bytes of data by a superimposition signal in a superimposable period included in one frame, and 50 frames in a unit time T1 (= 1 s). As an example, a transmission signal of (F1 to F50) is transmitted. Here, the superimposition communication terminal 4 performs inter-terminal communication of the first protocol at a communication frequency of once per second, transmits 15-byte data each time, and performs inter-terminal communication of the second protocol in 2 seconds. An example will be described in which transmission is performed once and 15-byte data is transmitted each time.

In the example of FIG. 7, in the allocation information, the second frame F2 of the transmission signal is allocated to the first protocol every 1 second (= unit time T1), and the 50th frame F50 is allocated to the second protocol every 2 seconds. Assigned. Further, the arbitrating unit 14 transmits a synchronization signal in the first frame F1 every second (= unit time T1).

Therefore, the superimposition communication terminals 401 and 402 synchronize the first protocol during the superimposable period of the second frame F2 of the transmission signal every second according to the allocation information received in advance while synchronizing the unit time T1 with the synchronization signal. Communication between terminals is performed using the superimposed signal. In addition, the superimposition communication terminals 411 and 412 synchronize with the synchronization signal for the unit time T1, and in accordance with the allocation information received in advance, the superimposition communication terminals 411 and 412 perform the second protocol in the superimposable period of the 50th frame F50 of the transmission signal every 2 seconds. Communication between terminals is performed using the superimposed signal.

According to the configuration of the present embodiment described above, the arbitrating unit 14 performs the allocation by transmitting the allocation information indicating the allocation of the superimposable period to the superimposed communication terminal 4 in advance to the superimposed communication terminal 4. It can be efficiently used for communication between terminals. That is, in the configuration of the first embodiment, every time the superimposed communication terminal 4 performs inter-terminal communication, a part of the superimposable period is used for transmission of communication permission. Can also be used for communication between terminals. Therefore, in the communication system of the present embodiment, it is possible to improve the communication speed of communication between terminals.

Further, in the present embodiment, the arbitration unit 14 can superimpose signals used for superimposing the superimposed signal in units of each period (preliminary interrupt period 31, spare period 32, pause period 37) in one frame of the transmission signal. The structure which allocates a period may be sufficient. In this case, for example, the arbitration unit 14 can assign the preliminary interruption period 31 and the preliminary period 32 of the transmission signal to the first protocol, and assign the pause period 37 to the superimposed signal of the second protocol. In this way, when the arbitrating unit 14 assigns a superimposable period in units of each period within one frame of the transmission signal, communication between terminals using a superposed signal of a plurality of protocols is possible in a relatively short span.

Other configurations and functions are the same as those in the first embodiment.

In the configuration in which the arbitrating unit 14 determines allocation of a superimposable period based on communication information collected from the superimposed communication terminal 4, the arbitrating unit 14 sequentially transmits communication permission to the superimposed communication terminal 4 and performs allocation. 1 may be combined.

(Embodiment 3)
As shown in FIG. 8, the communication system according to the present embodiment is that the transmission unit 1 includes a protocol conversion unit 17 that converts a superimposed signal of one protocol into a superimposed signal of another protocol. Is different.

The protocol conversion unit 17 is connected between the transmission processing unit 13 and the arbitration unit 14, acquires the superimposed signal received by the superimposition reception unit 16 via the arbitration unit 14, and transmits the superimposed signal after the protocol conversion to the arbitration unit. 14 from the superimposition transmission unit 15 to the transmission path 2. Thereby, when a plurality of sets of superimposed communication terminals 4 with different protocols are provided on the same transmission path 2, the superimposed communication terminals 4 with different protocols can communicate with each other via the protocol conversion unit 17.

In other words, the superimposition communication terminals 401 and 402 using the superimposition signal of the first protocol and the superimposition communication terminals 411 and 412 using the superimposition signal of the second protocol cannot communicate directly, but the protocol conversion unit 17 is used. It becomes possible to communicate with each other. Therefore, for example, the superimposed communication terminal 401 as a master communicates with the superimposed communication terminal 412 via the superimposed communication terminal 411 by communicating with the superimposed communication terminal 411 as another master via the transmission unit 1. It becomes possible to do.

In addition, when the superimposition signal whose protocol has been converted by the protocol conversion unit 17 is sent to the transmission path 2, the arbitration unit 14 superimposes the superimposition signal in the superimposable period assigned to the converted protocol in the transmission signal. Thus, the transmission timing of the superimposed signal is controlled. That is, when the protocol conversion unit 17 converts the superimposition signal of the first protocol into the superimposition signal of the second protocol, the arbitration unit 14 performs the protocol conversion after the protocol conversion in accordance with the superimposable period assigned to the second protocol. Send superimposition signal. Thereby, the transmission unit 1 can avoid collision between superimposed signals, while enabling communication between the superimposed communication terminals 4 having different protocols.

Here, the protocol conversion unit 17 has a conversion table for mutually converting superimposed signals of different protocols, and converts the protocol according to this conversion table. In this embodiment, the protocol conversion unit 17 superimposes a superposition signal of one protocol received by the superposition reception unit 16 on a superposition of another protocol to which a superimposition possible period is assigned next to the one protocol in the arbitration unit 14. Convert to signal. For example, when the arbitrating unit 14 alternately assigns the superimposable period to the first protocol and the second protocol, the protocol conversion unit 17 converts the first protocol to the second protocol, Convert protocol to first protocol.

Hereinafter, specific operations of the communication system will be described. Here, communication between terminals of the first protocol performed by the superimposed communication terminals 401 and 402 is used for power measurement, and communication between terminals of the second protocol performed by the superimposed communication terminals 411 and 412 is used for dimming control of the lighting fixture. Take the case of being used as an example.

In this case, the power consumption measured by the monitored device 7 connected to the superimposed communication terminal 402 is transmitted to the superimposed communication terminal 401 as a superimposed signal of the first protocol, and the protocol conversion unit 17 uses the second protocol. Is also transmitted to the superimposed communication terminal 411. The monitoring device 6 connected to the superimposition communication terminal 411 determines the dimming level of the luminaire based on the power consumption, and superimposes the dimming level from the superimposition communication terminal 411 using the superimposition signal of the second protocol. Transmit to the communication terminal 412. As a result, information (power consumption) exchanged in communication between terminals of the first protocol is reflected in information (light control level) exchanged in communication between terminals of the second protocol.

According to the configuration of the present embodiment described above, the superimposition communication terminals 4 having different protocols can communicate with each other via the protocol conversion unit 17, and therefore, the monitoring device 6 connected to the superposition communication terminals 4 having different protocols A cooperative operation with the monitored device 7 becomes possible. As a result, the communication system has an advantage that various devices can be connected to the same transmission path 2 via the superimposition communication terminal 4 and the expandability of the system can be improved by cooperation between the devices. .

By the way, when there are three or more types of superimposition signal protocols, the protocol conversion unit 17 selects other superposition signals of a plurality of types of protocols received by the superposition reception unit 16 based on additional information added to the superposition signal. It may be configured to convert to a protocol superimposition signal. The additional information here is information indicating the priority of the superimposed signal, such as control information, priority information, and emergency information.

For example, when the superimposable period is assigned to the first, second, and third protocols in order, the protocol conversion unit 17 normally sets the first protocol to the second protocol and the second protocol to the second protocol. The third protocol is converted into the first protocol. On the other hand, when the additional information that requires cooperation with the third protocol is added to the superimposed signals of the first and second protocols, the protocol conversion unit 17 adds the superimposed signals of the first and second protocols. Based on the above, a superimposed signal of the third protocol is generated.

Hereinafter, specific operations of the communication system will be described. Here, inter-terminal communication of the second protocol performed by the superimposed communication terminals 411 and 412 is used for illuminance measurement on the desk surface, and inter-terminal communication of the third protocol performed by another superimposed communication terminal (not shown). The case where it is used for dimming control of a lighting fixture is taken as an example. Further, inter-terminal communication of the first protocol performed by the superimposition communication terminals 401 and 402 is used for power measurement as in the above example.

In this case, the power consumption measured by the monitored device 7 connected to the superimposed communication terminal 402 is transmitted to the superimposed communication terminal 401 using the first protocol, and the monitored device 7 connected to the superimposed communication terminal 412 measures the power consumption. The transmitted illuminance is transmitted to the superimposed communication terminal 411 using the second protocol. The superimposition signals of the first and second protocols are added with additional information indicating the third protocol to be converted, and converted into a superimposition signal of the third protocol by the protocol conversion unit 17, It is also transmitted to a superimposition communication terminal that performs inter-terminal communication of the above protocol.

The monitoring device 6 connected to the superimposition communication terminal of the third protocol determines the dimming level of the lighting fixture based on the power consumption and the illuminance. For example, the monitoring device 6 reduces the dimming level when the power consumption is large and the illuminance is high, and maintains the dimming level when the power consumption is large and the illuminance is low. The monitoring device 6 maintains the dimming level when the power consumption is small and the illuminance is low, and increases the dimming level when the power consumption is small and the illuminance is small. As a result, information (power consumption) exchanged by communication between terminals of the first protocol and information (illuminance) exchanged by communication between terminals of the second protocol are exchanged by communication between terminals of the third protocol. It will be reflected in the information (dimming level).

According to this configuration, the protocol conversion unit 17 can flexibly determine the protocol conversion destination based on the additional information added to the superimposed signal, and transmits urgent data to terminals of other protocols. It can be transmitted with priority over inter-communication.

Other configurations and functions are the same as those in the first embodiment.

Note that the configuration of the present embodiment may be combined with the configuration of the second embodiment.

While the invention has been described in terms of several preferred embodiments, various modifications and variations can be made by those skilled in the art without departing from the true spirit and scope of the invention, ie, the claims.

Claims (13)

1. A transmission unit that repeatedly transmits a transmission signal to a transmission line, a terminal device that communicates using the transmission signal, and a terminal that uses a superimposed signal that is superimposed on the transmission signal and that employs a unique protocol. A communication system in which a plurality of sets of superimposed communication terminals that perform communication are connected to the transmission path, wherein the transmission signal is divided into a plurality of periods in a time axis direction for each frame, and a part of the period is A signal of a time division method in which a superimposition signal can be superimposed and a remaining period is a non-superimposition period that is not used for superimposition of the superimposition signal, and the transmission unit is different between the specific protocols. An arbitration unit that assigns the superimposable period to each of the unique protocols so that the superimposable periods used for inter-terminal communication do not overlap. Communication system to be butterflies.
2. Each set of superimposed communication terminals in the plurality of sets of superimposed communication terminals includes a superimposed communication terminal as a master and a superimposed communication terminal as at least one slave, and the superimposed communication terminal as a master has a unique protocol. 2. The communication system according to claim 1, wherein the inter-terminal communication is performed with the superimposed communication terminal as the slave belonging to the same set using the superimposed signal employing the above.
3. The arbitration unit sequentially transmits communication permission to each set of superimposed communication terminals in the plurality of sets of superimposed communication terminals in accordance with the allocation of the superimposable period, and each set of superimposed communication terminals receives the communication permission. The communication system according to claim 1, wherein the communication between terminals is started.
4. Each set of superimposed communication terminals, when the inter-terminal communication ends, transmits an end notification to the arbitration unit, and the arbitration unit transmits the next communication permission after receiving the end notification. The communication system according to claim 3.
5. When the arbitration unit receives an interrupt request from one of the plurality of sets of superimposed communication terminals, the communication to the one set of superimposed communication terminals that issued the interrupt request 5. The communication system according to claim 3, wherein permission is transmitted with priority.
6. The arbitration unit transmits allocation information indicating allocation of the superimposable period to the specific protocol to each set of superimposed communication terminals in the plurality of sets of superimposed communication terminals, and the plurality of sets of superimposed communication terminals. Periodically transmitting a synchronization signal that synchronizes between, and each of the sets of superimposed communication terminals, according to the allocation information received in advance from the arbitration unit and the synchronization signal received periodically The communication system according to claim 1, wherein the inter-terminal communication is performed during the superimposable period assigned to a protocol.
7. The said mediation part collects the communication information regarding the said communication between terminals from the said multiple sets of superimposition communication terminal, and determines allocation of the said superimposable period based on the said communication information. The communication system according to any one of 6.
8. The transmission unit is a protocol conversion unit that converts the superimposed signal of one specific protocol received from one set of superimposed communication terminals of the plurality of sets of superimposed communication terminals into the superimposed signal of another specific protocol. The arbitration unit sends the superimposition signal converted by the protocol conversion unit during the superimposable period assigned to the other unique protocol. The communication system according to any one of the above.
9. The protocol conversion unit includes the superimposition signal of the one specific protocol, and the superimposition signal of the other specific protocol to which the superimposition possible period is allocated next to the one specific protocol in the arbitration unit. The communication system according to claim 8, wherein the communication system is converted into:
10. There are three or more types of the unique protocols of the superimposed signal, and the transmission unit adds the superimposed signals of a plurality of types of unique protocols received from the plurality of sets of superimposed communication terminals to the superimposed signal. A protocol conversion unit that converts the superimposed signal into another specific protocol based on additional information, and the arbitration unit assigns the superimposed signal converted by the protocol conversion unit to the other specific protocol. The communication system according to any one of claims 1 to 7, wherein the communication is performed during the superimposable period.
11. The communication system according to claim 10, wherein the additional information includes information indicating a unique protocol as a conversion destination.
12. A transmission unit that repeatedly transmits a transmission signal to a transmission line, a terminal device that communicates using the transmission signal, and a terminal that uses a superimposed signal that is superimposed on the transmission signal and that employs a unique protocol. Used in a communication system in which a plurality of sets of superimposed communication terminals that perform communication are connected to the transmission path, the transmission signal is divided into a plurality of periods in a time axis direction for each frame, and a part of the period is A signal of a time division method in which a superimposition signal can be superimposed and a remaining period is a non-superimposition period that is not used for superimposition of the superimposition signal, and is used for inter-terminal communication between different specific protocols A transmission unit comprising: an arbitration unit that assigns the superimposable period to each of the unique protocols so that the superimposable periods are not overlapped. Door.
13. A protocol converter that converts the superimposed signal of one specific protocol received from one set of the superimposed communication terminals of the plurality of sets of superimposed communication terminals into the superimposed signal of another specific protocol; 13. The transmission unit according to claim 12, wherein the arbitration unit sends out the superimposed signal converted by the protocol conversion unit during the superimposable period assigned to the other unique protocol.

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