JP2007006086A - Power-line carrier communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power-line carrier communication device capable of automatically setting an optimum communication path by easily discriminating the new installation of a terminal and the change of transmission characteristics, when the terminal is installed anew and when transmission characteristics are changed by the alteration or the like of a power load. <P>SOLUTION: The power-line carrier communication device has a repeater 10 and a plurality of the terminals 11 to 15 placed under the repeater 10 and having a function relaying the communications of other terminals. The terminals 11 to 15 have communication-path quality decision means deciding the qualities of communication paths, and a communication-path setting means for setting the optimum communication path by selecting the relaying terminal on the basis of a decision by the communication-path quality decision means. When the terminal 15 is fitted anew, the communication-path quality decision means and the communication-path setting means for the terminal 15 automatically set the communication path having the highest percentage of a communication success as the optimum communication path. When the percentage of the communication success is lower than a threshold value, the optimum communication path is searched anew and updated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power line carrier communication device that uses a low-voltage power line as a transmission line, and in particular, when a terminal is newly installed or when transmission characteristics change due to a change in power load, etc., automatically The present invention relates to a power line carrier communication device capable of setting an optimum communication path.

  Conventionally, the communication path in the power line carrier communication device is a fixed communication path constructed according to the inter-terminal communication path information input to the terminal in advance through human hands, and each terminal is fixed by this construction. Communicate using a common communication path.

  Power line carrier communication, unlike LAN and dedicated lines, cannot communicate stably. The first reason is that the transmission power is regulated legally, so that when the distance between the communicating terminals is long, the signal attenuation during transmission is large, and it is difficult to transmit information far away. It is. The second reason is that there is no guarantee that normal communication can always be performed afterwards even if the communication path has been successfully communicated until now because the transmission characteristics of the communication path being used deteriorate due to changes in the power load. That is. That is, in power line carrier communication, the load impedance due to power line noise and power line resonance changes every moment due to load fluctuations of power consumers and the like, so that transmission characteristics such as signal-to-noise ratio may be deteriorated. For this reason, in the power line carrier communication, it is difficult to obtain a performance that enables communication in the entire apartment, for example.

  In order to avoid this communication failure, when a communication failure occurs in the communication path being used, a communication possible route may be searched and the communication may be changed to the communication route searched for. For example, if there are multiple terminals that relay communication, and there is room for selecting a communication path for relaying to which terminal to communicate with the other terminal, there is no communication failure by changing the relay terminal What is necessary is just to change to a communication path.

  However, when changing the communication path, it is necessary to determine which terminal the communication path is optimal through, but this determination is difficult. By repeating the communication test several times while confirming the power line system, it is possible to select a terminal to be relayed and set an optimal communication path. However, a large-scale apartment or the like spends a lot of time. Further, even when the optimum communication path is determined, the conventional power line carrier communication apparatus has a problem that it requires time and effort to input new inter-terminal communication path information to each terminal again through manual labor.

  The object of the present invention is to solve the above-mentioned problems, and when a terminal is newly installed or a change in transmission characteristics occurs due to a change in power load, etc., it is easily determined and an optimum communication path is automatically set. It is in providing the power line carrier communication apparatus which can do.

  In order to solve the above-described problems, the present invention provides a power line carrier communication device that uses a low-voltage power line as a communication path, and has a relay and a plurality of functions that are located under the relay and relay communication of other terminals. The communication terminal quality determining means for determining the quality of the communication path leading to the repeater, and selecting the terminal to relay based on the determination by the communication path quality determining means. A first feature is that a communication path setting means for setting a path is provided.

  In addition, the present invention has a second feature in that the communication path quality determination means uses the communication success rate calculated in the communication test as an index of the quality of the communication path.

  Further, according to the present invention, the communication path setting means transmits a call signal to the upper terminal by broadcast communication, and cancels a response from a terminal other than the upper terminal having the highest communication success rate with the repeater. There is a third feature in that a communication path including a host terminal that has a means and responds to the call signal is set as an optimal communication path.

  Further, according to the present invention, when the communication path setting means has a communication success rate lower than a predetermined threshold, the stored information on the optimum communication path is discarded, and the quality of the new communication path by the communication path quality determination means is determined. A fourth feature is that the optimum communication path is updated by selecting a new relay terminal based on the determination.

  The fifth feature of the present invention is that the repeater periodically performs a communication test with a subordinate terminal to calculate a communication success rate, and notifies the communication success rate to the terminal. is there.

  Furthermore, the present invention has a sixth feature in that the network under the repeater is distinguished from the network under other repeaters by the serial number of the repeater.

  According to the present invention, the optimum communication path is automatically set according to the quality of the communication path when the terminal is newly installed or when the transmission characteristic changes due to a change in the power load. It is possible to automatically construct an optimum communication path without being conscious of the system and without requiring manpower.

  In addition, it is not necessary to improve the hardware transmission / reception performance, and it is possible to set a communication path with a high communication success rate by software and to update to a communication path with a high communication success rate. A device can be constructed.

  The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a power line carrier communication apparatus to which the present invention is applied. The power line carrier communication apparatus of this embodiment includes a repeater 10 and terminals 11 to 15. Terminals 11 to 15 communicate via a communication path using a low-voltage power line. There are a plurality of communication paths from the terminal 15 to the repeater 10. The repeater 10 manages IDs and addresses based on the unique information of the terminals 11 to 15 under its control, and is disposed, for example, at the low-voltage power line entrance of a large-scale apartment to relay to the outside. The terminals 11 to 15 are arranged in each customer's house and have a function of relaying communication of other terminals.

  Here, the terminal 11 can directly communicate with the repeater 10, the terminals 12 to 14 can communicate with the terminal 11, and the terminal 15 can communicate with any of the terminals 12 to 14 through the terminal 11. And If the “connection level” is defined as the number of stages from the repeater 10, the connection level of the repeater 10 is “0”, the connection level of the terminal 11 is “1”, and the connection levels of the terminals 12 to 14 are “2”.

  The repeater 10 and the terminals 11 to 15 are assigned addresses, IDs, and NIDs. FIG. 1 also shows specific examples thereof. The address is a fixed value unique to each device and is written at the time of shipment from the factory. The NID is a unique ID that is used as a communication address in partial communication described later, and is written in the communication IC. The ID of the repeater 10 is a fixed value of “7e”, for example, and the IDs of the terminals 11 to 14 are automatically given by the repeater 10 at the time of installation, and are “01” to “04”, for example. Further, the terminal 15 is given an ID indicating unregistration, for example, “7c”.

  The repeater 10 and the terminals 11 to 14 store communication path information indicating a communication path between the devices using an ID correspondence table. FIG. 2 shows a specific example of communication path information. The communication path information is obtained by associating the terminal ID with the upper connection ID. In this example, the terminal 11 “01” is located below the repeater 10 “7e”, and the terminal is located below the terminal 11 “01”. 12 to 14 “02” to “04” are located. Further, according to the communication path information, it is possible to know what connection level the terminal is located at.

  Each of the terminals 11 to 14 performs a communication test with the repeater 10 when the power is turned on or when a predetermined button is pressed, and calculates and holds a communication success rate. The repeater 10 periodically performs a communication test with each of the terminals 11 to 14, for example, every hour, calculates a communication success rate, and distributes it to the terminals 11 to 14. Each of the terminals 11 to 14 calculates a new communication success rate from the communication success rate held by itself and the communication success rate periodically distributed from the repeater 10, and updates the held communication success rate. In each communication test, the communication success rate is preferably an average value of communication success rates obtained by a plurality of transmissions / receptions.

For example, assuming that the communication success rate held by the terminal 12 is A and the communication success rate periodically distributed from the repeater 10 to the terminal 12 is B, for example, the value calculated by the following formula is the new communication success rate C be able to.
C = (A + (B × OMOMI)) / (1 + OMOMI)

  Here, OMOMI represents the weight of the communication success rate B. If OMOMI is set to 10 or 5, for example, the communication success rate B, that is, the latest communication success rate is emphasized. Only the communication success rate B can be set as the new communication success rate. If OMOMI is set to 1, the new communication success rate C can be obtained by calculating the average value by simply adding A and B and dividing by 2. FIG. 3 shows the relationship between the communication success rates A, B, and C and OMOMI.

  Next, an operation when an optimum communication path is constructed in the power line carrier communication apparatus according to the present invention will be described. First, an operation of automatically constructing an optimum communication path from the terminal 15 to the repeater 10 when the terminals 11 to 14 are existing terminals and the terminal 15 is newly installed will be described. FIG. 4 is a flowchart showing the operation in this case. The operations described below can be realized by software.

  When the terminal 15 is newly installed, the communication path change processing routine is automatically started. First, the terminal 15 uses the ID “7c” indicating unregistered information, calls a terminal and a repeater that can issue terminal IDs using a domain communicable with all terminals and repeaters (S1). This is a process of searching for a terminal that can communicate with the terminal 15.

  The IC for repeaters and terminals has a function to manage and use two domains, a domain that can be communicated with all terminals and repeaters and a unique domain for each repeater. An ID under a domain that can be communicated by all terminals and repeaters (a fixed domain number set in advance by a program) is used as an address. As the ID under the domain unique for each repeater, a domain number generated based on the repeater manufacturing number (serial number) is given when the repeater is manufactured.

  When the terminals 12 to 14 located at the connection stage “2” receive the call, the terminals 12 to 14 manage the response after the elapse of time until the start of the response obtained from the communication success rate between the own terminal and the repeater 10. From the communication path information, the lowest ID that is available for the terminal ID and the address of the own terminal are transmitted to the terminal 15.

  Here, assuming that the communication success rate with the repeater 10 is the highest in the terminal 12, the terminal 12 returns the response earliest (S2). Upon receiving the free ID “05” and the address “KC000003” from the terminal 12, the terminal 15 provisionally registers the received ID “05” as the ID of its own terminal, and transmits a response stop command without specifying the terminal (S3 ). The response stop command is transmitted because a response from the terminals 11, 13, 14 other than the terminal 12 and the repeater 10 is unnecessary.

  The terminals 13 and 14 having a communication success rate with the repeater 10 lower than that of the terminal 12, even when receiving a call from the terminal 12, the time until the response start is longer than that of the terminal 12, the free ID and the own terminal Since the response stop command is received from the terminal 15 before transmitting the address as a response, it is suppressed that the response is sent to the terminal 15 in vain. Even if the terminals 13 and 14 cannot receive the response stop command, and there is a response from them, those responses are discarded by the terminal 15 (S4).

  Note that the terminal 15, the terminal 11, and the repeater 10 are separated from each other by several hundred meters, for example, and the call signal from the terminal 15 does not reach the terminal 11 or the repeater 10 directly due to attenuation in the middle. Therefore, there is no response from the terminal 11 or the repeater 10, and those responses are discarded by the terminal 15 if any.

  Next, the terminal 15 calls the repeater 10 to confirm the presence of the repeater 10 (S5). The terminal 15 has not yet grasped the specific terminal that relays the calling signal to the repeater 10. Therefore, the repeater 10 is called by not specifying a specific address, specifying a connection level “0”, and further specifying a communication success rate if necessary, and requesting a response from a device that meets this condition. Specifying the connection level “0” means that the device located at the connection level “0”, that is, the repeater 10 is set as a response target. Specifying the connection level “1” means that the devices located in the connection levels “0” to “1”, that is, the repeater 10 and the terminal 11 are targeted for response. The same applies to the designation of connection level “2”.

  The repeater 10 does not respond because it exists at a position where the call signal from the terminal 15 cannot be detected. In other words, without specifying a specific address, even if the connection level `` 0 '' is specified and relayed to the terminals 12 to 14 and the repeater 10 is called, the terminal 15 and the repeater 10 are separated by, for example, several hundred meters, The calling signal from the terminal 15 does not reach the repeater 10 directly due to midway attenuation or noise on the power line. Further, the call signal does not reach the repeater 10 from the point that the call signal is simultaneously transmitted from the terminals 12 to 14 to the upper side and the line congestion occurs.

  When there is no response from the repeater 10, that is, when there is no response from anywhere within a predetermined time, the terminal 15 specifies the connection level “1” that can communicate with the repeater 10 and calls this condition. A response is requested to the matched devices (repeater 10 and terminal 11) (S6).

  Similarly to the repeater 10, the terminal 11 located at the connection stage “1” does not respond because it exists at a position where the call signal from the terminal 15 cannot be detected. If there is no response from the terminal 11 located at the connection level “1”, the connection level “2” that can be communicated with the terminal located at the connection level “1” is specified and called, and this condition is met. A response is requested to the device (the repeater 10 and the terminals 11 to 14) (S7).

  The terminals 12 to 14 located at the connection stage “2” are present at a position where the call signal can be detected. When the terminals 12 to 14 receive the calling signal, the terminal ID is vacant from the communication path information managed by the own terminal after the time until the response start determined from the communication success rate between the own terminal and the repeater 10 has elapsed. The youngest ID and the address of its own terminal are transmitted to the terminal 15.

  Since it is assumed that the terminal 12 has the highest communication success rate with the repeater 10 and that the response from the terminal 12 is the earliest, the terminal 12 returns the empty ID “05” as a response (S8). The terminal 15 receives and stores the free ID “05” from the terminal 12, and transmits a response stop command without designating the terminal (S9). The response stop command is transmitted because the response from the terminals 13 and 14 is unnecessary.

  The terminals 13 and 14 having a communication success rate with the repeater 10 lower than the terminal 12 receive a call signal from the terminal 12, and the response start time is longer than that of the terminal 12, and the ID is used as a response. Since the response stop command is received from the terminal 15 before transmission, it is possible to suppress the useless transmission of the response to the terminal 15. Even if the terminals 13 and 14 cannot receive the response stop command and there is a response from them, the information is discarded at the terminal 15 (S10).

  Next, the terminal 15 given the ID “05” from the terminal 12 uses the unique information (address “KC000001” and NID “001058513600”) of the terminal 15 in order to check whether a communication route to the repeater 10 exists. The data is transmitted to the terminal 12, and the repeater 10 is instructed to transfer in the bucket relay system (S11). This transmission is performed using the ID of the terminal 12 received and stored previously. The terminal 12 transfers the received unique information of the terminal 15 to the terminal 11 (S12), and stores the NID for later transmission to the terminal 15. The terminal 11 further transfers the unique information of the terminal 15 to the repeater 10 (S13). The transfer from the terminal 12 to the repeater 10 is performed using communication path information.

  When receiving the specific information of the terminal 15, the repeater 10 returns a response to the terminal 15 to the terminal 15. For this reason, the lowest unused ID ("05" in this example) among the terminal IDs managed by the own repeater 10 is transmitted to the terminal 11 and transferred to the terminal 12 in a bucket relay system. (S14). At this time, the route “7e” → “01” → “02” is designated based on the communication route information.

  The terminal 11 transfers the ID “05” transmitted from the repeater 10 to the terminal 12 (S15). The terminal 12 further transfers it to the terminal 15 in a bucket relay manner (S16). The transfer from the terminal 12 to the terminal 15 is performed using the previously stored NID “001058513600”. The NID is used here, for example, when there is another terminal newly installed at the same time as the terminal 15, the ID “05” may be assigned to it, and the ID “05” from the repeater 10 is assigned. This is because it may be transferred to another terminal. If a completely unique NID is used as a communication address for each device, there is no fear.

  As described above, the terminal 15 to which the ID “05” is indirectly assigned from the repeater 10 officially registers the ID “05”. Thereafter, the terminal 15 continuously performs a communication test with the terminal 12 that directly communicates with the terminal 15 (S17). If a communication success rate above a certain level is obtained in the communication test with the terminal 12, the terminal 15 determines that the communication path between the terminal 12 and the terminal 12 is a stable communication path. Is transmitted to the terminal 12 and transferred to the repeater 10 in a bucket relay manner (S18). At this time, the route “02” → “01” → “7e” is designated based on the communication route information. The terminal 12 transfers the received communication path determination instruction information of the terminal 15 to the terminal 11 (S19), and the terminal 11 further transfers it to the repeater 10 (S20).

  The repeater 10 receives the communication path determination instruction information, determines and stores the ID “05” of the terminal 15. Also, the ID “02” of the terminal 12 as a terminal directly communicating with the newly registered terminal 15 is simultaneously stored as communication path information. Here, the ID “05” of the terminal 15 and its communication path information are formally registered in the repeater 10. At this stage, since the communication test (S17) between the terminal 15 and the terminal 12 has been completed, stable communication with the stored communication path information can be expected.

  Subsequently, the repeater 10 transmits the route confirmation information of the terminal 15 to the terminal 11, specifies the route “7e” → “01” → “02” → “05”, and transfers it to the terminal 15 in a bucket relay system. (S21). The terminal 11 transfers the received route determination information of the terminal 15 to the terminal 12 (S22), and the terminal 12 further transfers it to the terminal 15 (S23). The route confirmation information includes route information between the terminal 15 and the terminal 12, that is, information indicating that the upper terminal of the terminal 1 is the terminal 12, and the terminals 11 and 12 may copy this information to the own terminal. Good. As a result, the terminals 11 and 12 surely store the latest route information even if the communication route information is lost in the subsequent simultaneous delivery.

  After receiving the route determination information, the terminal 15 determines the communication route and completes registration. Thereafter, the repeater 10 distributes the communication path information all at once to all the terminals subordinate to the repeater 10 using a common address of the terminals belonging to the subordinate repeater (S24). The terminal receiving simultaneous distribution from the repeater 10 retransmits the communication path information after the delay time obtained from the communication success rate of the terminal itself has elapsed (S25).

  All terminals including the repeater 10 have the same communication route information, and the terminal 15 that cannot communicate directly with the repeater 10 can construct a route using the existing terminals 12 and 11 as a repeater.

  Next, when the terminal 15 has already been installed and the communication at the terminal 15 is interrupted for a certain period of time or when the communication success rate falls below a certain value, the communication path is automatically changed to change the optimum communication path. The construction operation will be described. FIG. 5 is a flowchart showing the operation in this case. In FIG. 5, the same or equivalent parts as in FIG.

  In this case, since the terminal 15 has already been assigned an ID, an optimal communication path may be constructed using the ID. Each terminal 11-15 calculates and holds the communication success rate with the repeater 10 as described above. Based on the communication success rate calculated by the terminal 15, the terminal 15 determines whether the communication has been interrupted for a certain period of time or the communication success rate has decreased below a certain value. The determination of a decrease in the communication success rate below a certain value is made by comparing the calculated communication success rate with a minimum communication success rate, for example, 10%.

  When the communication success rate falls below the minimum communication success rate, the terminal 15 activates a communication path change processing routine. The subsequent operation is the same as (S1) to (S25) in FIG. However, the ID returned by the terminal 12 for provisional registration is unused “06”. Further, when receiving the specific information of the terminal 15, the repeater 10 returns the ID of the terminal 15 already managed by the own repeater 10 ("05" in this example) to the terminal 15 as a response thereto. A temporary ID “06” is temporarily assigned to the terminal 15, but the original ID “05” is thereafter given.

  Although the embodiments have been described above, the present invention is not limited to the above-described embodiments and can be variously modified. For example, in power line carrier communication, one network is constructed by a transformer load-side repeater and a terminal, but a signal of the network may circulate to a neighboring network via a transformer. The network No. generated based on the serial number of the repeater is used to distinguish between networks, and the terminal receives the domain No. from the repeater prior to communication, and the network of the domain No. You can prevent this wraparound if you participate in.

  In addition, a 1-to-N (N is an integer of 2 or more) communication method may be prepared for backup so as to cope with a case where communication is impossible by one-to-one communication. In the one-to-N communication method, a terminal that determines that information received as a one-to-N broadcast is not addressed to itself retransmits the received information. However, the transmission source ID and the transmission destination ID are stored, and when the same information is received again, it is discarded so that a loop is not formed.

It is a block diagram which shows one Embodiment of the power line carrier communication apparatus with which this invention was applied. It is a figure which shows the specific example of communication path information. It is explanatory drawing of communication success rate calculation. It is a flowchart which shows operation | movement in the case of constructing | assembling an optimal communication path when a terminal is newly established It is a flowchart which shows operation | movement in the case of establishing an optimal communication path | route when communication stops for a fixed time, or when a communication success rate falls.

Explanation of symbols

10 ... Repeater, 11-15 ... Terminal

Claims (6)

In a power line carrier communication device that uses a low-voltage power line as a communication path,
A repeater and a plurality of terminals located under the repeater and having a function of relaying communication of other terminals;
The terminal comprises a communication path quality determination means for determining the quality of a communication path leading to the repeater;
A power line carrier communication apparatus comprising: a communication path setting unit that sets an optimal communication path by selecting a terminal to be relayed based on determination by the communication path quality determination unit. The power line carrier communication apparatus according to claim 1, wherein the communication path quality determination means uses the communication success rate calculated in the communication test as an index of the quality of the communication path. The communication path setting means includes a means for transmitting a call signal to the upper terminal by broadcast communication, and canceling a response from a terminal other than the upper terminal having the highest communication success rate with the repeater, The power line carrier communication apparatus according to claim 2, wherein a communication path including a higher-level terminal responding to the call signal is set as an optimum communication path. When the communication success rate falls below a predetermined threshold, the communication path setting unit discards the stored information on the optimum communication path and newly relays based on the determination of the quality of the new communication path by the communication path quality determination unit. The power line carrier communication apparatus according to claim 1, wherein the optimum communication path is updated by selecting a terminal to be operated. The power line carrier according to claim 2, wherein the repeater periodically performs a communication test with a subordinate terminal to calculate a communication success rate, and notifies the terminal of the communication success rate. Communication device. 6. The power line carrier communication apparatus according to claim 1, wherein a network under the relay is distinguished from a network under another relay by the serial number of the relay.

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