JP2018011179A - Communication apparatus and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication apparatus and a communication system capable of reducing a state that any communication signal cannot be sent in a power line communication with the communication module.SOLUTION: A communication apparatus 1 performs a power line carrier communication to transmit communication signals with a communication module 2 connected to the same distribution line 4 by using a distribution line 4 as a transmission medium. The communication apparatus 1 includes: a communication part 12 that transmits and receives communication signals with the communication module 2; and a control unit 11 that controls the communication part 12. The control unit 11 is configured to execute a series of sensitivity reduction processing to reduce the reception sensitivity of the communication part 12 depending on the communication conditions on the distribution line 4.SELECTED DRAWING: Figure 1

Description

  The present invention generally relates to a communication device and a communication system, and more particularly to a communication device and a communication system that perform power line carrier communication with a communication module.

  2. Description of the Related Art Conventionally, a device management system that performs power line carrier communication between a meter device (communication module) installed in a consumer and a device has been provided (see, for example, Patent Document 1). The communication module is a so-called smart meter, and is connected to a distribution line to which commercial power is supplied from an electric power company, and measures the power supplied to the consumer. The device is, for example, a HEMS (Home Energy Management System) device, and operates in cooperation with the communication module by performing power line carrier communication with the communication module via the first communication path.

JP 2016-28549 A

  In a device management system (communication system) as described in Patent Document 1, it is preferable to perform carrier sense before transmitting a communication signal in order to avoid collision of communication signals. In the case of power line carrier communication, unlike wireless communication, the reception sensitivity when receiving communication signals is the same as the reception sensitivity of carrier sense, so if the reception sensitivity is set high, noise etc. in carrier sense May be erroneously detected as a communication signal. As a result, in the above-described communication system, there is a possibility that the communication signal cannot be transmitted even though the communication signal can be transmitted.

  This invention is made | formed in view of the said subject, and it aims at providing the communication apparatus and communication system which can reduce the state which cannot transmit a communication signal in power line carrier communication with a communication module.

  The communication apparatus which concerns on 1 aspect of this invention performs the power line carrier communication which transmits a communication signal using the said distribution line for a transmission medium between the communication modules connected to the same distribution line. The communication device includes a communication unit that transmits and receives the communication signal to and from the communication module, and a control unit that controls the communication unit. The control unit is configured to execute a sensitivity reduction process that lowers the reception sensitivity of the communication unit in accordance with a communication situation in the distribution line.

  The communication system which concerns on 1 aspect of this invention is the power line carrier communication which transmits a communication signal using the said distribution line as a transmission medium between the above-mentioned communication apparatus and the said communication apparatus connected to the same distribution line. A communication module to perform.

  The present invention has an effect of reducing the state in which a communication signal cannot be transmitted in power line carrier communication with a communication module.

It is a block diagram which shows the structure of the communication apparatus which concerns on Embodiment 1 of this invention, and a communication system. It is a flowchart explaining operation | movement of a communication apparatus same as the above. It is explanatory drawing explaining operation | movement of the communication apparatus which concerns on Embodiment 2 of this invention. It is a flowchart explaining operation | movement of a communication apparatus same as the above. It is a flowchart explaining operation | movement of the communication apparatus which concerns on Embodiment 3 of this invention. It is a block diagram which shows the structure of the communication apparatus which concerns on Embodiment 4 of this invention. It is a flowchart explaining operation | movement of a communication apparatus same as the above. It is a flowchart explaining operation | movement of the communication apparatus which concerns on Embodiment 5 of this invention. It is a flowchart explaining operation | movement of the communication apparatus which concerns on the modification of Embodiment 5 of this invention.

  Hereinafter, a communication device and a communication system according to embodiments of the present invention will be specifically described with reference to the drawings. However, the configuration described below is merely an example of the present invention, and the present invention is not limited to the following first to fifth embodiments. Therefore, various modifications can be made in accordance with the design and the like in a range that does not depart from the technical idea according to the present invention other than the first to fifth embodiments.

(Embodiment 1)
As illustrated in FIG. 1, the communication system 10 according to the present embodiment includes a communication device 1, a communication module 2, and a device 3. In the present embodiment, as shown in FIG. 1, a plurality (three in the illustrated example) of communication systems 10 are connected to the same distribution line 4. Since each communication system 10 has the same configuration, only one communication system 10 will be described below, and description of the remaining communication systems 10 will be omitted.

  In the following description, the case where the communication system 10 is applied to a detached house is illustrated, but the building to which the communication system 10 is applied is not limited to a detached house, for example, each dwelling unit, office, factory, etc. of an apartment house. Also good. Moreover, in the following description, although the case where electric power is measured by the measurement part 23 of the communication module 2 is illustrated, the measurement object of the measurement part 23 is not restricted to electric power, For example, gas, water supply etc. may be sufficient.

  Communication between the communication device 1 and the communication module 2 is realized by using power line communication (PLC) technology that transmits a communication signal using the distribution line 4 as a transmission medium. That is, a communication path using the distribution line 4 as a transmission medium is formed between the communication device 1 and the communication module 2.

  The communication module 2 is, for example, a smart meter, and includes a calculation unit 21, a wired communication unit 22, and a measurement unit 23 as illustrated in FIG.

  The computing unit 21 is composed of, for example, a microcomputer mainly composed of a CPU (Central Processing Unit) and a memory, and the microcomputer functions as the computing unit 21 when the CPU executes a program stored in the memory. To do. Here, the program executed by the CPU is recorded in advance in the memory of the arithmetic unit 21, but may be provided by being recorded on a recording medium such as a memory card, or may be provided through an electric communication line.

  The wired communication unit 22 is configured to perform power line carrier communication bidirectionally with the communication device 1 (a communication unit 12 described later) using the distribution line 4 as a transmission medium.

  The measuring unit 23 is connected to the distribution line 4 to which power is supplied from a power supplier, and measures the amount of power used in a detached house. The measurement unit 23 outputs measurement data including at least the power consumption measured every certain time (for example, 1 minute, 5 minutes, 10 minutes, etc.) to the calculation unit 21.

  The calculation unit 21 is configured to store measurement data from the measurement unit 23 in a memory for a certain period (for example, one day). Moreover, the calculating part 21 is comprised so that the communication signal containing the measurement data from the measurement part 23 may be transmitted to the communication apparatus 1 from the wired communication part 22 for every predetermined time (for example, 30 minutes).

  The communication device 1 is, for example, a B route adapter that relays between the communication module 2 and the device 3. The communication device 1 performs power line carrier communication with the communication module 2 and performs wireless communication with the device 3. Here, the “B route” refers to a communication route connecting the communication module 2 (smart meter) and the device 3. As shown in FIG. 1, the communication device 1 includes a control unit 11, a communication unit 12, and a wireless communication unit 13.

  The control unit 11 is composed of, for example, a microcomputer having a CPU and a memory as main components, and the microcomputer functions as the control unit 11 when the CPU executes a program stored in the memory. The program executed by the CPU is recorded in advance in the memory of the control unit 11 here, but may be provided by being recorded on a recording medium such as a memory card or may be provided through an electric communication line.

  The communication unit 12 is configured to perform power line carrier communication bidirectionally with the communication module 2 (wired communication unit 22) using the distribution line 4 as a transmission medium.

  For example, the wireless communication unit 13 forms a Wi-SUN (Wireless Smart Utility Network) together with the device 3 and wirelessly communicates with the device 3 bidirectionally using radio waves in a frequency band of about 900 MHz called a sub-gigahertz band. I do.

  The device 3 is, for example, a HEMS (Home Energy Management System) controller. The device 3 has, for example, a function of transferring measurement data of a detached house sent from the communication device 1 to a server, a function of displaying the measurement data on a display device, a function of controlling an HEMS-compatible electric device, and the like. ing.

  By the way, in the communication system 10 of this embodiment, the communication apparatus 1 and the communication module 2 are connected to the same distribution line 4, and it is comprised so that power line carrier communication may be performed using the distribution line 4 as a transmission medium. Yes. That is, the communication device 1 and the communication module 2 are configured to transmit a communication signal to the same distribution line 4. Therefore, when the communication device 1 and the communication module 2 transmit a communication signal at the same timing, the communication device 1 may not receive the communication signal from the communication module 2. Therefore, the communication device 1 is preferably configured to perform carrier sense before transmitting a communication signal to the communication module 2. Here, “carrier sense” refers to confirming whether there is another apparatus that is currently communicating before starting communication. The carrier sense is preferably a CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) system, for example. The communication device 1 can avoid collision between communication signals by performing carrier sense before transmitting the communication signal to the communication module 2, and as a result, receives the communication signal from the communication module 2. can do.

  In the present embodiment, a plurality of communication systems 10 are connected to the same distribution line 4. Therefore, a communication signal from the communication device 1 or the communication module 2 of another communication system 10 may be transmitted to the communication device 1 of each communication system 10 via the distribution line 4. In this case, when each communication device 1 receives the communication signal in carrier sense, the communication device 1 transmits the communication signal even though the communication signal can be transmitted to the corresponding communication module 2. I can't. Further, in a situation where noise is superimposed on the distribution line 4, each communication device 1 may erroneously detect the noise as a communication signal in carrier sense. In this case, the communication signal may be transmitted. Can not. From the above, it is preferable that each communication device 1 is configured to perform a sensitivity reduction process for reducing the reception sensitivity of the communication unit 12 when a communication signal is received in carrier sense. Hereinafter, the sensitivity reduction process in the communication apparatus 1 will be described with reference to FIG.

  When the communication signal cannot be transmitted from the communication unit 12 to the communication module 2 (step S1), the control unit 11 determines whether or not transmission is possible due to carrier sense (step S2). If the transmission is not possible due to carrier sense (Yes in step S2), the control unit 11 executes a sensitivity reduction process for reducing the reception sensitivity of the communication unit 12 (step S3). In this case, in the carrier sense, the communication unit 12 receives a communication signal from the communication device 1 or the communication module 2 of the other communication system 10, or erroneously detects noise superimposed on the distribution line 4 as a communication signal. It is assumed that On the other hand, the control part 11 does not perform a sensitivity reduction process, when the communication part 12 is a transmission impossible state except carrier sense (No of step S2).

  Here, when the communication unit 12 is in a transmission disabled state other than carrier sense, for example, the communication unit 12 may not receive a response (ACK: ACKnowledgement) signal from the communication module 2 to the communication signal transmitted from the communication unit 12. is assumed. Therefore, in this case, it is preferable that the control unit 11 is configured not to execute the sensitivity reduction process but also to execute a sensitivity improvement process for increasing the reception sensitivity of the communication unit 12.

  In the communication device 1 of this embodiment, when the control unit 11 is in a transmission disabled state due to carrier sense, a communication signal from the communication device 1 or the communication module 2 of another communication system 10 connected to the same distribution line 4 or It is determined that noise has been received, and sensitivity reduction processing is executed. Thereby, it becomes difficult to receive the communication signal and noise from the communication apparatus 1 or the communication module 2 of the other communication system 10, and the state which cannot transmit a communication signal from the communication part 12 in the communication apparatus 1 can be reduced.

  Hereinafter, modifications of the first embodiment will be described.

  In the first embodiment, in each communication system 10, the case where the communication device 1 and the device 3 correspond one-to-one has been described. However, a plurality of devices 3 are configured to correspond to one communication device 1. May be. In other words, the communication device 1 and the device 3 may be configured to correspond to a pair N (N = 2, 3, 4,...). In the first embodiment, the case where there are three communication systems 10 connected to the same distribution line 4 is illustrated. However, the number of communication systems 10 connected to the distribution line 4 is not limited to three, but one or two It may be one or four or more.

  Furthermore, the first embodiment is configured to execute the sensitivity reduction process when the transmission is impossible due to carrier sense. On the other hand, for example, an acquisition unit that acquires the traffic amount in the distribution line 4 may be provided, and the sensitivity reduction process may be executed when the traffic amount acquired by the acquisition unit is equal to or greater than a specified value.

  In addition, after the sensitivity reduction process is performed, the reception sensitivity of the communication unit 12 decreases, and thus it is difficult for the communication unit 12 to receive communication signals (including response signals) from the communication module 2 of the same communication system 10. There is sex. Therefore, even after the control unit 11 executes the sensitivity reduction process, the sensitivity is improved to increase the reception sensitivity of the communication unit 12 in the first period so that the communication unit 12 can easily receive the communication signal from the communication module 2. It is preferable that the control unit 11 execute the process. The first period is a period after the communication unit 12 transmits a communication signal and until the communication unit 12 receives a response signal from the communication module 2 with respect to the communication signal. In this case, when the response signal from the communication module 2 is received, the reception sensitivity of the communication unit 12 is high, and there is an advantage that the response signal can be easily received.

(Embodiment 2)
Embodiment 2 of the communication apparatus 1 and the communication system 10 will be described with reference to FIGS. 3 and 4. Note that the configurations of the communication device 1 and the communication system 10 are the same as those in the first embodiment, and the same components are denoted by the same reference numerals, description thereof is omitted, and FIG. 1 is referred to as necessary.

  In the first embodiment described above, the control unit 11 is configured to execute the sensitivity reduction process depending on whether or not transmission is possible due to carrier sense. On the other hand, in the present embodiment, the control unit 11 performs the sensitivity reduction process based on the magnitude of the S / N ratio of the communication signal from the communication module 2 as well as whether or not transmission is possible due to carrier sense. Is configured to run.

  FIG. 3 is an explanatory diagram for explaining the operation of the communication apparatus 1 according to the present embodiment. At time t1, the control unit 11 causes the communication unit 12 to perform carrier sense. When the communication unit 12 can transmit a communication signal by carrier sense, the communication unit 12 transmits a communication signal to the communication module 2 at time t2. At time t3, the communication unit 12 receives a response signal from the communication module 2. At this time, the control unit 11 acquires an LQI value corresponding to the S / N ratio of the response signal received by the communication unit 12 at time t3. The LQI value is a value indicating radio wave communication quality, and is represented by a numerical value from 0 to 255 in a form corresponding to the magnitude of the S / N ratio. Then, when executing the sensitivity reduction process for reducing the reception sensitivity of the communication unit 12, the control unit 11 sets the LQI value corresponding to the S / N ratio of the response signal received at time t3 and the reference value of the S / N ratio. The threshold value of the corresponding LQI value is compared. Here, the reference value of the S / N ratio of the communication signal is determined for each modulation method.

  At time t4, the control unit 11 causes the communication unit 12 to perform carrier sense. When the communication unit 12 cannot transmit a communication signal due to carrier sense, the communication unit 12 cannot transmit a communication signal to the communication module 2 and also receives a response signal from the communication module 2 for the communication signal. I can't. In this case, as described in the first embodiment, the communication unit 12 is highly likely to receive a communication signal from the communication device 1 or the communication module 2 of the other communication system 10. Sensitivity needs to be lowered. That is, since the communication unit 12 is in a transmission disabled state due to carrier sense at time t4, if the LQI value of the response signal acquired at time t3 is equal to or greater than the threshold value, the carrier unit at time t5 receives the communication unit 12. Sensitivity will be lowered.

  Next, the sensitivity reduction process in the communication apparatus 1 of this embodiment is demonstrated with reference to FIG.

  When the communication signal cannot be transmitted from the communication unit 12 to the communication module 2 (step S11), the control unit 11 determines whether or not transmission is possible due to carrier sense (step S12). When the transmission is not possible due to carrier sense (Yes in step S12), the control unit 11 determines the LQI value corresponding to the S / N ratio of the response signal acquired when the response signal from the communication module 2 is received, and S The threshold value corresponding to the reference value of the / N ratio is compared (step S13). Then, when the LQI value is equal to or greater than the threshold value (Yes in Step S13), the control unit 11 executes a sensitivity reduction process for reducing the reception sensitivity of the communication unit 12 (Step S14). On the other hand, the control unit 11 does not execute the sensitivity reduction process when the communication unit 12 is in a transmission disabled state other than carrier sense (No in Step S12) or when the LQI value is smaller than the threshold (No in Step S13). .

  Here, when the communication unit 12 is in a transmission disabled state other than carrier sense, for example, it is assumed that the communication unit 12 cannot receive a response signal from the communication module 2 with respect to the communication signal transmitted from the communication unit 12. Therefore, in this case, it is preferable that the control unit 11 is configured not to execute the sensitivity reduction process but also to execute a sensitivity improvement process for increasing the reception sensitivity of the communication unit 12.

  In the communication device 1 according to the present embodiment, when the transmission is not possible due to carrier sense and the S / N ratio (LQI value) of the communication signal from the communication module 2 is equal to or higher than the reference value (threshold), the sensitivity reduction process Is configured to run. As a result, it is possible to reduce the state in which the communication unit 12 cannot transmit the communication signal while it is difficult to reduce the reception accuracy of the communication signal from the communication module 2.

  Hereinafter, modifications of the second embodiment will be described.

  In the second embodiment, the S / N ratio of the response signal from the communication module 2 to the communication signal transmitted from the communication unit 12 has been described as an example. However, the S / N ratio of the communication signal from the communication module 2 may be used. The S / N ratio of the response signal from the communication module 2 is not limited.

  Further, in the second embodiment, in the comparison between the two values of the S / N ratio (LQI value) and the reference value (threshold value), “not less than” indicates that the two values are equal and one of the two values is It is meant to include both the case where it exceeds the other. However, the present invention is not limited thereto, and “more than” may be synonymous with “greater than” including only when one of the two values exceeds the other. That is, whether or not the case where the two values are equal can be arbitrarily changed depending on the setting of the reference value (threshold value), so there is no technical difference between “greater than” or “greater than”. Similarly, “below” may be synonymous with “less than”.

  Furthermore, the configuration described in the second embodiment can be applied in appropriate combination with the modification described in the first embodiment.

(Embodiment 3)
Embodiment 3 of the communication apparatus 1 and the communication system 10 will be described with reference to FIG. Note that the configurations of the communication device 1 and the communication system 10 are the same as those in the first embodiment, and the same components are denoted by the same reference numerals, description thereof is omitted, and FIG. 1 is referred to as necessary.

  When the communication unit 12 is in a transmission disabled state except for carrier sense, it is assumed that the communication unit 12 cannot receive a communication signal (including a response signal) from the communication module 2. Therefore, in this case, it is preferable that the control unit 11 is configured to execute a sensitivity improvement process for increasing the reception sensitivity of the communication unit 12 so that a communication signal from the communication module 2 can be received. Hereinafter, the operation of the communication apparatus 1 of the present embodiment will be described with reference to FIG.

  When the communication signal cannot be transmitted from the communication unit 12 to the communication module 2 (step S21), the control unit 11 determines whether or not transmission is possible due to carrier sense (step S22). If the transmission is not possible due to carrier sense (Yes in step S22), the control unit 11 executes a sensitivity reduction process for reducing the reception sensitivity of the communication unit 12 (step S23). On the other hand, when the communication unit 12 is in a transmission disabled state except for carrier sense (No in step S22), the control unit 11 executes a sensitivity improvement process for increasing the reception sensitivity of the communication unit 12 (step S24).

  As described above, when the communication unit 12 is in a transmission disabled state except for carrier sense, it is assumed that the communication unit 12 cannot receive a communication signal from the communication module 2. Therefore, in this case, the control unit 11 can increase the reception sensitivity of the communication unit 12 by executing the sensitivity improvement process, and as a result, the communication signal (including the response signal) from the communication module 2 is received. be able to.

  The configuration described in Embodiment 3 can be applied in appropriate combination with the configuration and modifications of Embodiment 1. The configuration described in the third embodiment can be applied in appropriate combination with the configuration and modification of the second embodiment.

(Embodiment 4)
Embodiment 4 of the communication apparatus 1 and the communication system 10 is demonstrated with reference to FIG.6 and FIG.7. This embodiment is different from the first to third embodiments in that the communication device 1 further includes a first counting unit 111 and a second counting unit 112. In addition, about the structure similar to Embodiment 1-3, the same code | symbol is attached | subjected, detailed description is abbreviate | omitted, and FIG. 1 is referred as needed.

  As illustrated in FIG. 6, the communication device 1 according to the present embodiment includes a control unit 11, a communication unit 12, a wireless communication unit 13, a first counting unit 111, and a second counting unit 112.

  The first counting unit 111 is a counter provided in a microcomputer, for example. The first counting unit 111 counts the number of times that the communication unit 12 has become unable to transmit a communication signal (hereinafter referred to as a first state) due to carrier sense within a specified time (for example, 7 hours).

  Similar to the first counting unit 111, the second counting unit 112 is a counter provided in, for example, a microcomputer. The second counting unit 112 is the number of times that the communication unit 12 cannot receive a response signal from the communication module 2 with respect to the communication signal transmitted from the communication unit 12 within a specified time period (hereinafter referred to as a second state). Count.

  The control unit 11 compares the first count value, which is the count value of the first count unit 111, with the second count value, which is the count value of the second count unit 112, and calculates the first count value and the second count value. The reception sensitivity of the communication unit 12 is adjusted according to the size of the. Hereinafter, the operation of the communication apparatus 1 of the present embodiment will be described with reference to FIG.

  The control unit 11 counts the number of times the first state is reached within the specified time by the first counting unit 111, counts the number of times the second state is reached within the specified time by the second counting unit 112, and the first count The first count value of the unit 111 is compared with the second count value of the second count unit 112 (step S31). When the first count value is larger than the second count value (Yes in step S32), the control unit 11 executes a sensitivity reduction process for reducing the reception sensitivity of the communication unit 12 (step S33). In this case, it is assumed that the communication unit 12 is receiving a communication signal from the communication device 1 or the communication module 2 of another communication system 10 due to the high reception sensitivity of the communication unit 12. On the other hand, when the second count value is greater than or equal to the first count value (No in step S32), the control unit 11 executes a sensitivity improvement process for increasing the reception sensitivity of the communication unit 12 (step S34). In this case, it is assumed that the response signal from the communication module 2 cannot be received because the reception sensitivity of the communication unit 12 is low.

  In the communication device 1 of the present embodiment, the reception sensitivity is lowered when the transmission state in the communication unit 12 is bad, and the reception sensitivity is raised when the reception state is bad, and the reception sensitivity of the communication unit 12 is set according to the communication situation. Can be adjusted.

  The configuration described in the fourth embodiment can be applied in appropriate combination with the configuration and the modification of the first embodiment. The configuration described in the fourth embodiment can be applied in appropriate combination with the configuration and modification of the second embodiment. Furthermore, the configuration described in the fourth embodiment can be applied in appropriate combination with the configuration of the third embodiment.

(Embodiment 5)
Embodiment 5 of the communication apparatus 1 and the communication system 10 will be described with reference to FIGS. 8 and 9. In the above-described fourth embodiment, the communication apparatus 1 includes both the first counting unit 111 that counts the number of times that the communication device 1 has entered the first state and the second counting unit 112 that counts the number of times that the communication device 1 has entered the second state. However, only the first counting unit 111 (counting unit) may be provided. In this case, it is preferable that the control unit 11 is configured to compare the count value of the first counting unit 111 with a preset threshold value and adjust the reception sensitivity of the communication unit 12 according to the comparison result. . Hereinafter, the operation of the communication apparatus 1 of the present embodiment will be described with reference to FIG.

  When the communication signal cannot be transmitted from the communication unit 12 to the communication module 2 (step S41), the control unit 11 determines whether or not transmission is possible due to carrier sense (step S42). When the transmission is not possible due to carrier sense (Yes in step S42), the control unit 11 (first counting unit 111) adds 1 to the current count value n and sets a new count value n (step S43). As a result of comparing the count value n with the threshold value, if the count value n exceeds the threshold value (No in step S44), the control unit 11 executes a sensitivity reduction process for reducing the reception sensitivity of the communication unit 12 (step S45). ). Then, the control part 11 resets the count value n to 0 (step S46). On the other hand, when the communication unit 12 is in a transmission disabled state except for carrier sense (No in Step S42), or when the count value n of the first counting unit 111 is equal to or less than a threshold (No in Step S44), Do not perform sensitivity reduction processing.

  Here, when the communication unit 12 is in a transmission disabled state other than carrier sense, for example, it is assumed that the communication unit 12 cannot receive a response signal from the communication module 2 with respect to the communication signal transmitted from the communication unit 12. Therefore, in this case, it is preferable that the control unit 11 is configured not to execute the sensitivity reduction process but also to execute a sensitivity improvement process for increasing the reception sensitivity of the communication unit 12.

  The communication device 1 according to the present embodiment is configured not to perform the sensitivity reduction process until the count value n of the first counting unit (counting unit) 111 exceeds the threshold value. A reduction in reception sensitivity can be suppressed.

  By the way, in the communication apparatus 1 shown in FIG. 8, the threshold value to be compared with the count value n is fixed, but for example, as shown in FIG. 9, the threshold value may be changed. Hereinafter, a communication device 1 according to a modification of the present embodiment will be described with reference to FIG.

  When the communication signal cannot be transmitted from the communication unit 12 to the communication module 2 (step S51), the control unit 11 determines whether or not transmission is possible due to carrier sense (step S52). When the transmission is not possible due to carrier sense (Yes in Step S52), the control unit 11 (first counting unit 111) adds 1 to the current count value n and sets a new count value n (Step S53). On the other hand, when the communication unit 12 is in a transmission disabled state except for carrier sense (No in step S52), the control unit 11 increases the threshold value by one step from the initial value (step S54). When the count value n exceeds the threshold value as a result of comparing the count value n with the threshold value (step S55), the control unit 11 executes a sensitivity reduction process for reducing the reception sensitivity of the communication unit 12 (step S56). Thereafter, the control unit 11 resets the count value n to 0 (step S57) and resets the threshold value to the initial value (step S58). Note that the threshold need not be reset. On the other hand, as a result of comparing the count value n with the threshold value, the control unit 11 does not execute the sensitivity reduction process when the count value n is equal to or less than the threshold value (No in step S55).

  In the communication device 1 of this modification, when the communication unit 12 is in a transmission disabled state except for carrier sense, a situation where the communication unit 12 cannot receive a response signal from the communication module 2 is assumed. In this case, since the control unit 11 increases the threshold value of the count value n, it is possible to reduce the decrease in the reception sensitivity of the communication unit 12 even though the reception state of the communication unit 12 is not good.

  By the way, in the above-mentioned embodiment and modification, although the case where the control part 11 was provided with only the 1st counting part 111 was demonstrated, even if the control part 11 is provided with only the 2nd counting part 112 (counting part). Good. In this case, the control unit 11 compares the count value of the second count unit 112 with a threshold value, and performs a sensitivity improvement process that increases the reception sensitivity of the communication unit 12 when the count value exceeds the threshold value. It is preferable that When the count value exceeds the threshold value, it is assumed that the communication unit 12 is difficult to receive the response signal from the communication module 2, and the response signal is transmitted to the communication unit by increasing the reception sensitivity of the communication unit 12. There is an advantage that 12 becomes easy to receive.

  The configuration described in the fifth embodiment can be applied in appropriate combination with the configuration and the modification of the first embodiment. The configuration described in the fifth embodiment can be applied in appropriate combination with the configuration and modification of the second embodiment. Furthermore, the configuration described in the fifth embodiment can be applied in appropriate combination with the configuration of the third embodiment.

  As described above, the communication device 1 according to the first aspect performs power line carrier communication for transmitting a communication signal using the distribution line 4 as a transmission medium with the communication module 2 connected to the same distribution line 4. Do. The communication device 1 includes a communication unit 12 that transmits and receives communication signals to and from the communication module 2 and a control unit 11 that controls the communication unit 12. The control unit 11 is configured to execute a sensitivity reduction process that lowers the reception sensitivity of the communication unit 12 according to the communication status in the distribution line 4. In the communication device 1 according to the first aspect, the control unit 11 is configured to execute a sensitivity reduction process that lowers the reception sensitivity of the communication unit 12 according to the communication status in the distribution line 4. Therefore, for example, the reception sensitivity of the communication unit 12 is set high, and even when noise or the like is erroneously detected as a communication signal in carrier sense, it is difficult to detect erroneously by lowering the reception sensitivity. A state in which a signal cannot be transmitted can be reduced.

  In the first mode, the communication device 1 of the second mode is configured such that the control unit 11 causes the communication unit 12 to perform carrier sense before transmitting a communication signal from the communication unit 12. The control unit 11 is configured to perform sensitivity reduction processing when the communication unit 12 receives a communication signal in carrier sense. According to the communication device 1 of the second aspect, it is possible to reduce a state in which a communication signal cannot be transmitted by erroneously detecting, for example, noise as a communication signal in carrier sense.

  In the first aspect, the communication device 1 according to the third aspect is configured such that the control unit 11 causes the communication unit 12 to perform carrier sense before transmitting a communication signal from the communication unit 12. When the communication unit 12 receives the communication signal in the carrier sense and the S / N ratio of the communication signal acquired when the communication unit 12 receives the communication signal from the communication module 2 is greater than the reference value. In addition, the sensitivity reduction process is executed. In the communication device 1 of the third aspect, not only the communication unit 12 receives a communication signal in carrier sense, but also when the S / N ratio of the communication signal from the communication module 2 is equal to or higher than a reference value, the control unit 11 It is configured to execute a sensitivity reduction process. As a result, it is possible to reduce the state in which the communication signal cannot be transmitted while it is difficult to reduce the reception accuracy of the communication signal from the communication module 2.

  In the communication device 1 according to the fourth aspect, in the second or third aspect, when the control unit 11 cannot receive the communication signal from the communication module 2 after executing the sensitivity reduction process, It is configured to execute a sensitivity improvement process for increasing reception sensitivity. According to the communication device 1 of the fourth aspect, when the communication unit 12 cannot receive the communication signal from the communication module 2, the sensitivity improvement process is performed, and thereby the communication signal from the communication module 2 is transmitted to the communication unit 12. Becomes easier to receive.

  In the second or third aspect, the communication device 1 according to the fifth aspect is configured such that the control unit 11 executes a sensitivity improvement process that increases the reception sensitivity in the first period after the sensitivity reduction process. ing. The first period is a period after the communication unit 12 transmits a communication signal and until the communication unit 12 receives a response signal from the communication module 2 with respect to the communication signal. According to the communication device 1 of the fifth aspect, when receiving a communication signal from the communication module 2, the communication unit 12 receives the communication signal from the communication module 2 because the reception sensitivity of the communication unit 12 is increased. It becomes easy to do.

  The communication device 1 according to the sixth aspect further includes a first counting unit 111 and a second counting unit 112 in any one of the second to fifth aspects. The first counting unit 111 counts the number of times that the communication unit 12 has become unable to transmit a communication signal due to carrier sense within a specified time. The second counting unit 112 counts the number of times the reception signal cannot be received from the communication module 2 with respect to the communication signal transmitted from the communication unit 12 within the specified time. The control unit 11 is configured to execute a sensitivity reduction process when the count value of the first count unit 111 is larger than the count value of the second count unit 112. Further, the control unit 11 is configured to execute a sensitivity improvement process for increasing the reception sensitivity when the count value of the second count unit 112 is larger than the count value of the first count unit 111. According to the communication device 1 of the sixth aspect, when the transmission state is poor in the communication unit 12, the reception sensitivity is lowered, and when the reception state is bad, the reception sensitivity is raised, and the reception sensitivity of the communication unit 12 is communicated. It can be adjusted according to the situation.

  In any one of the second to fifth aspects, the communication device 1 according to the seventh aspect is configured to count the number of times that the communication unit 12 has become unable to transmit a communication signal due to carrier sense. 1 counting unit 111). The control unit 11 is configured to execute a sensitivity reduction process when the count value of the counting unit exceeds a threshold value. According to the communication device 1 of the seventh aspect, the sensitivity reduction process is not performed until the count value of the counter exceeds the threshold. For example, the reception sensitivity of the communication unit 12 decreases due to noise or the like. Can be suppressed.

  In the communication device 1 according to the eighth aspect, in the seventh aspect, the control unit 11 sets the threshold when the communication unit 12 cannot receive a response signal from the communication module 2 with respect to the communication signal transmitted from the communication unit 12. It is configured to raise. According to the communication device 1 of the eighth aspect, when the communication unit 12 cannot receive the response signal from the communication module 2, the threshold for the count value of the counting unit is increased, so that the communication unit 12 is not receiving well. Nevertheless, it is possible to prevent the reception sensitivity of the communication unit 12 from being lowered.

  In any of the second to fifth aspects, the communication device 1 according to the ninth aspect cannot receive a response signal from the communication module 2 to the communication signal transmitted from the communication part 12 and cannot be received. A counter (second counter 112) that counts the number of times the state is reached is further provided. The control unit 11 is configured to execute a sensitivity improvement process for increasing the reception sensitivity when the count value of the counting unit exceeds a threshold value. According to the communication device 1 of the ninth aspect, since the sensitivity improvement processing is performed when the count value of the counting unit exceeds the threshold value, the communication unit 12 makes the response after the reception sensitivity of the communication unit 12 is increased. It becomes easier to receive signals.

  The communication system 10 according to the tenth aspect performs power line carrier communication for transmitting a communication signal using the distribution line 4 as a transmission medium between the communication apparatus 1 and the communication apparatus 1 connected to the same distribution line 4. And a communication module 2. According to the communication system 10 of the tenth aspect, in the power line carrier communication between the communication device 1 and the communication module 2, it is possible to reduce a state in which a communication signal cannot be transmitted from the communication device 1.

DESCRIPTION OF SYMBOLS 1 Communication apparatus 2 Communication module 4 Distribution line 10 Communication system 11 Control part 12 Communication part 111 1st counting part (counting part)
112 Second counting unit (counting unit)

Claims (10)

A communication device that performs power line carrier communication for transmitting a communication signal using the distribution line as a transmission medium with a communication module connected to the same distribution line,
A communication unit for transmitting and receiving the communication signal to and from the communication module;
A control unit for controlling the communication unit,
The said control part is comprised so that the sensitivity reduction process which lowers the receiving sensitivity of the said communication part may be performed according to the communication condition in the said distribution line. The communication apparatus characterized by the above-mentioned. The control unit is configured to cause the communication unit to perform carrier sense before transmitting the communication signal from the communication unit,
The communication device according to claim 1, wherein the control unit is configured to execute the sensitivity reduction process when the communication unit receives the communication signal in the carrier sense. The control unit is configured to cause the communication unit to perform carrier sense before transmitting the communication signal from the communication unit,
In the carrier sense, the S / N ratio of the communication signal acquired when the communication unit receives the communication signal in the carrier sense and the communication unit receives the communication signal from the communication module is a reference. The communication device according to claim 1, wherein the sensitivity reduction process is executed when the value is equal to or greater than a value. The control unit is configured to execute a sensitivity improvement process for increasing the reception sensitivity when the communication unit cannot receive the communication signal from the communication module after executing the sensitivity reduction process. The communication apparatus according to claim 2 or 3, wherein The control unit, after executing the sensitivity reduction process, after transmitting the communication signal from the communication unit and until the communication unit receives a response signal from the communication module with respect to the communication signal. The communication apparatus according to claim 2, wherein the communication apparatus is configured to execute a sensitivity improvement process for increasing the reception sensitivity. A first counting unit that counts the number of times the communication unit has become unable to transmit the communication signal due to the carrier sense within a specified time; and
A second counting unit that counts the number of times the communication unit cannot receive a response signal from the communication module with respect to the communication signal transmitted from the communication unit within the specified time;
The control unit executes the sensitivity reduction process when the count value of the first counter is larger than the count value of the second counter, and the count value of the second counter is equal to that of the first counter. The communication apparatus according to any one of claims 2 to 5, wherein the communication apparatus is configured to execute a sensitivity improvement process for increasing the reception sensitivity when larger than a count value. The counter further comprises a counting unit that counts the number of times that the communication unit becomes unable to transmit the communication signal due to the carrier sense,
The communication according to any one of claims 2 to 5, wherein the control unit is configured to perform the sensitivity reduction process when a count value of the counting unit exceeds a threshold value. apparatus. The said control part is comprised so that the said threshold value may be raised when the said communication part cannot receive the response signal from the said communication module with respect to the said communication signal transmitted from the said communication part. 7. The communication device according to 7. The counter further includes a counting unit that counts the number of times that the communication unit cannot receive a response signal from the communication module with respect to the communication signal transmitted from the communication unit,
The said control part is comprised so that the sensitivity improvement process which raises the said reception sensitivity may be performed when the count value of the said count part exceeds a threshold value. The any one of Claims 2-5 characterized by the above-mentioned. The communication apparatus as described in. The communication device according to any one of claims 1 to 9,
A communication module that performs power line carrier communication for transmitting a communication signal using the distribution line as a transmission medium with the communication device connected to the same distribution line.

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