KR102481512B1 - A method for automatic meter reading supporting coexistence of legacy metering device and smart metering device using power line communication and a smart modem device for the same - Google Patents

Abstract

An automatic meter reading method that supports the coexistence of legacy meters and smart meters is disclosed. The method includes acquiring first data that is at least a part of the serial number of the smart meter by communicating with a smart meter during a first time period, and communicating with a legacy meter during a second time period to obtain at least a part of the serial number of the legacy meter. Acquiring second data, generating a first code including the first data, storing the first code as an HDLC address of the smart meter, generating a second code including the second data, Storing a second code as the HDLC address of the legacy meter, generating a HDLC address list including the HDLC address of the smart meter and the HDLC address of the legacy meter, and first including the generated HDLC address list. and transmitting the power line communication packet to the DCU. At this time, the smart meter is configured to communicate with the meter-side smart modem using a first local communication protocol using MAC in the first time period, and the legacy meter communicates with the meter-side smart modem and MAC in the second time period. It is configured to communicate using the unused second local communication protocol.

Description

A method for automatic meter reading supporting coexistence of legacy metering device and smart metering device using power line communication and a smart modem device supporting coexistence of legacy meters and smart meters for the same}

The present invention relates to an automatic meter-reading technology using power line communication, and more particularly, to a technology enabling remote automatic meter-reading for both a conventional legacy meter and a new type of meter.

1 is a diagram for explaining a method in which a data control unit (DCU) reads a legacy meter (L.Meter) through a legacy modem (L.Modem) according to the prior art.

Hereinafter, the DCU is represented by a single-digit reference number 1, the legacy modem is represented by a two-digit reference number 1x, and the legacy meter is represented by a two-digit reference number 2x.

The DCU 1 uses the HDLC protocol to connect each of the legacy meters 21 and 22 with a communication channel, exchange information, and disconnect the communication channel. The HDLC protocol uses the HDLC packet 510, and the header 511 of the HDLC packet 510 includes a 1-byte or 2-byte HDLC address.

The legacy meters 21 and 22 have a serial number (S) consisting of 11 decimal digits. The legacy meters 21 and 22 may use 0 to 99, which are the lowest two decimal digits (LS) among the 11 decimal digits (S), as identifiers for identifying themselves. The least significant 2-digit number (LS) can be expressed with 1 byte. Therefore, even if the HDLC address included in the HDLC header 511 is 1 byte, there is no problem in that the HDLC address includes the least significant 2 digits (LS), and even if the HDLC address is 2 bytes, the HDLC address contains the least significant 2 digits There is no problem with including the number of digits (LS).

A pair of legacy modems 11 and 12 may perform a function of relaying data when the DCU 1 and the legacy meters 21 and 22 communicate with each other. Communication between the DCU-side legacy modem 11 and the meter-side legacy modem 12 may follow a power line communication protocol.

A separate MAC is not mounted on the legacy meters 21 and 22.

A system operating including the DCU 1, legacy modems 11 and 12, and legacy meters 21 and 22 described herein is referred to as a legacy power line communication AMR system 100 or simply a legacy system 100. can do. In this specification, a protocol used by the legacy power line communication AMR system 100 may be referred to as a legacy protocol.

In order to expand the network function of the meter, it is possible to develop a smart meter with a new configuration equipped with a MAC. In the present specification, a meter having such a new configuration may be simply referred to as a smart meter by distinguishing it from the legacy meter without a MAC. The legacy meter and the smart meter may be collectively referred to simply as a meter. The smart meter may also be referred to as an evolved meter.

When such a smart meter is installed in the legacy system, it is necessary to partially modify the legacy protocol in order for the legacy system to operate normally. When the legacy protocol is partially modified, devices participating in the legacy system need to be replaced with new ones or their firmware needs to be modified.

However, there may be two or more companies that design and manufacture new devices conforming to the new protocol in the conventional legacy system, and not all companies may agree on some modification of the legacy protocol.

Alternatively, even if all companies agree on partial modification of the legacy protocol, it may be technically or practically impossible to partially modify and apply the legacy protocol to legacy terminals or legacy meters following the legacy protocol.

Therefore, a company that intends to design and manufacture new devices conforming to a new protocol different from the legacy protocol and apply them to the existing legacy system must ensure the success of the operation of the devices conforming to the new protocol. The introduction of devices conforming to should not affect the operation, function, and purpose of legacy terminals following conventional legacy protocols. The smart modem may also be referred to as an evolved modem.

The present invention intends to provide a new method of adding and operating the new smart modems, the new DCU, and the new smart meter while maintaining the legacy meter of the legacy system.

Supporting the coexistence of a legacy meter 20 and a smart meter 40 using a meter-side smart modem 32 operating based on a predefined first protocol based on TDMA according to one aspect of the present invention An automatic weighing meter reading method can be provided. The automatic meter reading method may include obtaining first data, which is at least a part of a serial number of the smart meter, by communicating with the smart meter during a first time interval T1 by the TDMA, by the smart modem at the meter side; obtaining, by the smart modem at the meter, second data that is at least a part of the serial number of the legacy meter by communicating with a legacy meter during a second time period (T2) by the TDMA; The meter-side smart modem generates a first code including the first data, stores the first code as an HDLC address of the smart meter, generates a second code including the second data, and stores the first code as an HDLC address of the smart meter. 2 code as the HDLC address of the legacy meter; and the smart modem on the meter side generates an HDLC address list including the HDLC address of the smart meter and the HDLC address of the legacy meter, and transmits a first power line communication packet including the generated HDLC address list to the DCU (1). In the first time period, a first local communication protocol is used, and in the second time period, a master-slave second local communication protocol is used, and the smart meter and the meter side The smart modem may operate based on the first local communication protocol in the first time period, and the legacy meter and the meter-side smart modem may operate based on the second local communication protocol in the second time period. .

In this case, the first local communication protocol may be a CSMA/(CA+CD) protocol, and the second local communication protocol may be an RS485 protocol.

In this case, the smart meter may be configured to transmit an event generated in the smart meter to the smart modem on the meter side in a push method during the first time period.

At this time, during the first time period, the DCU or the smart modem on the meter side may be configured to obtain predetermined information from the smart meter by a polling method.

At this time, the transmission rate according to the first local communication protocol may be greater than the transmission rate according to the second local communication protocol.

At this time, the MAC frame exchanged through the local communication media provided between the smart modem on the meter side and the smart meter by the first local communication protocol includes a start flag (SF) and a total frame length from the start flag to the CRC. information, destination MAC address (DA), sender MAC address (SA), frame control (FC) information, sequence number (SN), command field (CMD), data, and the CRC.

At this time, the DCU is configured to transmit a scan request packet (SCAN.REQ) through a power line, and the scan request packet is provided between the power line, the meter-side smart modem, and the meter-side smart modem and the smart meter The scan request packet is a broadcast packet in which the MAC address of the sender is the MAC address of the DCU, and the DCU transmits the scan request packet As a response to , a scan response packet (SCAN.RESP) including the ID of the smart meter and the HDLC address of the smart meter may be received from the smart modem on the meter side.

In this case, the ID of the smart meter is an 11-digit decimal number, and the HDLC address of the smart meter may be an address generated by the smart modem on the meter side using the least significant 2 digits of the 11-digit decimal number.

In this case, the DCU may be a gateway.

At this time, the smart modem on the meter side is configured to transmit a beacon periodically, and if the smart meter has never transmitted the scan response packet as a response to the scan request packet, the smart meter responds to the beacon to send the smart It is configured to transmit a scan response packet (SCAN.RESP) including the ID of the meter and the HDLC address of the smart meter, and the beacon is a broadcast packet having the MAC address of the sender as the MAC address of the smart modem on the meter side. can be

At this time, the meter-side smart modem is configured to periodically transmit a beacon during the first time interval through a local communication medium provided between the meter-side smart modem and the smart meter, and each beacon is It includes information about the remaining time until the start of the 2-hour period and the total length of the second time period, and the smart meter controls communication of the legacy meter during the second time period based on the information included in the beacon. It may be configured to enter a do not disturb mode.

At this time, the smart meter and the legacy meter are connected to the fourth network interface 424 of the smart modem on the meter side, and the first power line communication packet is transmitted through the third network interface 323 of the smart modem on the meter side. It is intended to be transmitted to the DCU, and the third network interface may be an interface connecting to power line communication media.

At this time, the first power line communication packet is received by the DCU-side smart modem 31, and the DCU-side smart modem transmits the HDLC address list included in the first power line communication packet to the DCU. The DCU may be configured to acquire meter reading information from the legacy meter or the smart meter by performing communication according to the HDLC protocol with the legacy meter or the smart meter having the HDLC address included in the HDLC address list.

At this time, the automatic meter reading method may include receiving, by the smart modem on the meter side, a second power line communication packet including the HDLC packet 310 generated by the DCU; determining, by the smart modem at the meter, whether a first meter having an HDLC address included in the HDLC packet is the smart meter or the legacy meter, using the HDLC address list; and transmitting, by the meter-side smart modem, the HDLC packet to the first meter.

At this time, when it is determined that the first meter is the smart meter, the meter-side smart modem transmits the HDLC packet to the first meter using the first local communication protocol for a time period classified as the first time period. and when it is determined that the first meter is the legacy meter, the meter-side smart modem transmits the HDLC packet to the first meter in the second time interval using the second local communication protocol. It may be configured to transmit during a classified time period.

At this time, the automatic meter reading method may include receiving, by the smart modem at the meter side, a response message to the HDLC packet from the first meter; searching, by the smart modem for the meter, the HDLC address of the first meter from the HDLC address list, and generating a second HDLC packet using the searched address; and generating, by the meter-side smart modem, a third power line communication packet including the second HDLC packet, transmitting the generated third power line communication packet to the power line communication medium, and transmitting the generated third power line communication packet to the DCU. can

At this time, the MAC address for power line communication included in the generated third power line communication packet is the MAC address for power line communication of the DCU-side smart modem 31 connected to the DCU, and the DCU-side smart modem uses the power line communication MAC address in the third power line communication packet. The second HDLC packet may be extracted and provided to the DCU.

At this time, when it is determined that the first meter is the smart meter, the meter-side smart modem transmits the response message to the first meter using the first local communication protocol for a time period classified as the first time period. and if it is determined that the first meter is the legacy meter, the meter-side smart modem sends the response message to the first meter in the second time interval using the second local communication protocol. It may be set to receive during a classified time period.

In this case, the fourth network interface is used only during the first time period and may include a MAC using the first local communication protocol.

In the present invention, while maintaining the legacy meter of the legacy power line communication AMR system, a new smart modem is replaced or added, and the system is operated by adding the new smart meters, thereby evolving technology that coexists with the legacy meter technology. can provide a new way to promote

1 is a diagram for explaining a method in which a DCU reads a legacy meter through a legacy modem according to the prior art.
2 shows a smart modem and a new DCU according to an embodiment of the present invention, in a state in which a DCU and a legacy meter are maintained in a legacy automatic power meter reading system provided according to the prior art according to an embodiment of the present invention, a legacy modem and a DCU , and is a network configuration diagram showing the addition of a smart meter according to an embodiment of the present invention.
3 is a timing diagram illustrating a time-division access method used by a smart modem at the meter side according to an embodiment of the present invention.
4 is a flowchart illustrating a method in which a smart modem collects HDLC addresses of a smart meter and a legacy meter and provides the collected HDLC addresses of a smart meter and a legacy meter to a DCU among time-division automatic metering methods provided according to an embodiment of the present invention.
5 is a time-division automatic meter reading method provided according to an embodiment of the present invention, in which a smart modem receives an automatic meter reading command packet from the DCU, collects metering information accordingly, and sends the collected results back to the DCU. It is a flow chart showing how to provide.
6 is a timing diagram for explaining each state defined in the CSMA/(CA+CD) protocol used in an embodiment of the present invention.
7 shows the relationship between the use of RS485 driver TXE / nRXE and transmission and reception modes in the RS485 CSMA / (CA + CD) protocol according to an embodiment of the present invention.
8 illustrates an example of a structure of a frame according to the RS485 MAC protocol exchanged through a local communication medium provided between a smart modem and a smart meter at the meter side by a first local communication protocol according to an embodiment of the present invention. .
9 is a flowchart illustrating a process in which a DCU scans a meter ID based on an RS485 MAC according to an embodiment of the present invention.
10 shows a procedure for a newly added smart meter to report its own meter ID in an operating remote meter reading system.'
11 is a timing diagram for explaining a TDMA operation method of the RS485 MAC protocol provided according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be implemented in various other forms. Terms used in this specification are intended to aid understanding of the embodiments, and are not intended to limit the scope of the present invention. Also, the singular forms used herein include the plural forms unless the phrases clearly dictate the contrary.

Hereinafter, the DCU is represented by a single-digit reference number 1, the smart modem by a two-digit reference number 3x, the legacy meter by a two-digit reference number 2x, and the smart meter by a two-digit reference number 4x.

2 is a replacement of a legacy modem and a DCU with a smart modem and a new DCU according to an embodiment of the present invention in a state in which a legacy meter is maintained in a legacy automatic power meter reading system provided according to the prior art according to an embodiment of the present invention and a network configuration diagram showing that a smart meter is added according to an embodiment of the present invention. In one embodiment, the new DCU may be provided simply by modifying the firmware of the legacy DCU.

<Signal transfer from DCU to meter-side smart modem>

The DCU-side smart modem 31 according to an embodiment of the present invention includes a first network interface 311 locally connected to the DCU 1 and a second network interface 312 connected to the power line communication channel 71. can include The second network interface 312 may include a MAC 3100 for power line communication supporting power line communication.

The DCU 1 may use the HDLC protocol to communicate with the smart meters 41 , 42 , 43 or the legacy meters 21 , 22 . The DCU 1 may generate an HDLC packet including an HDLC address of a smart meter or a legacy meter that the DCU 1 wants to communicate with and provide the HDLC packet to the DCU-side smart modem 31 .

The smart meters 41 and 42 according to an embodiment of the present invention may provide the HDLC address by itself.

Alternatively, the smart meters 41 and 42 according to another embodiment of the present invention do not provide an HDLC address for the DCU to use, but the smart modem 32 on the meter side connected to the smart meters 41 and 42 Instead of the smart meters 41 and 42, the HDLC addresses of the smart meters 41 and 42 are created and managed, and the generated HDLC addresses can be used for communication with the DCU 1. To this end, the meter-side smart modem 32 obtains the serial numbers of the smart meters 41 and 42 from the smart meters 41 and 42, and based on the least significant 2 decimal digits of the serial numbers, the smart meters 41, 42) It is also possible to generate HDLC addresses for each.

In one embodiment, the meters connected to the smart modem 32 on the meter side may be limited to a specific number, for example 32, and more meters may not be connected.

In one embodiment of the present invention, legacy meters 21 and 22 may provide the HDLC address by itself.

Alternatively, the legacy meters 21 and 22 according to another embodiment of the present invention do not provide the HDLC address, but the smart modem 32 connected to the legacy meters 21 and 22 connects to the legacy meters 21 and 22. ), HDLC addresses of the legacy meters 21 and 22 are generated and managed, and the generated HDLC addresses can be used for communication with the DCU 1. To this end, the meter-side smart modem 32 acquires the serial numbers of the legacy meters 21 and 22 from the legacy meters 21 and 22, and the legacy meters 21 and 22 based on the least significant 2 decimal digits of the serial number. 22) It is also possible to generate HDLC addresses for each.

The payload 612 of the power line communication packet 610 generated by the DCU-side smart modem 31 may include the HDLC packet 510 provided by the DCU 1 to the DCU-side smart modem 31. .

In the header 611 of the power line communication packet 610 generated by the DCU-side smart modem 31, the power line communication MAC address ( PLC MAC address).

The HDLC packet 510 may be included in the payload 612 of the power line communication packet 610 flowing through the power line communication channel 71 .

<Signal transmission from the smart modem on the meter side to the smart meter or legacy meter>

The meter-side smart modem 32 according to an embodiment of the present invention is connected to the third network interface 323 connected to the power line communication channel 71 and the smart meter 40 and / or legacy meter 20 A fourth network interface 324 may be included. The third network interface 323 may include a MAC 3300 for power line communication supporting power line communication.

The fourth network interface 324 includes a MAC 3400 that supports a meter coexistence communication protocol that supports local communication with the smart meter 40 and/or the legacy meter 20, which is newly provided according to an embodiment of the present invention. ) may be included. The meter coexistence communication protocol is a predefined protocol based on TDMA, and may be referred to as a first protocol in this specification. In this specification, the first protocol may be referred to as an RS485 MAC protocol in other words. In the first protocol, a first time period and a second time period appearing alternately without overlapping on the time axis are defined. In the first protocol, a predetermined first local communication protocol may be used in the first time period, and a predetermined master-slave type second local communication protocol may be used in the second time period. In a preferred embodiment, the first local communication protocol may be CSMA/(CA+CD) protocol, and the second local communication protocol may be RS485 protocol.

This MAC 3400 may be referred to herein as a meter coexistence MAC 3400 or a local coexistence MAC 3400 or an RS485 MAC 3400.

A meter coexistence MAC corresponding to the RS485 MAC (3400) may also be included in the smart meter (40).

In this case, the RS485 MAC 3400 included in the fourth network interface 324 may be assigned a MAC address for master meter communication, which is a MAC address unique to the fourth network interface 324.

A communication channel connecting the fourth network interface 324 and the smart meter 40 and/or the legacy meter 20 may be wired or wireless. 81) or local communication media 81.

Hereinafter, in this specification, a group of smart meters 40 and a group of legacy meters connected to the fourth network interface 324 of one meter-side smart modem (ex: 32) through the local communication medium 81 s 20 may be referred to as 'locally' connected to the one meter-side smart modem (ex: 32).

The RS485 MAC protocol can communicate with the group of smart meters 40 and the group of legacy meters 20 connected to the fourth network interface 324 using a time division access method.

3 is a timing diagram illustrating a time division access method used by the smart modem 32 at the meter side according to an embodiment of the present invention.

That is, the fourth network interface 324 communicates with the group of smart meters 40 in the first predetermined time interval T1, but does not communicate with the group of legacy meters 20. In addition, the fourth network interface 324 does not communicate with the group of smart meters 40 in the second predetermined time interval T2, but communicates with the group of legacy meters 20. The first time period T1 and the second time period T2 may be repeated while crossing each other on the time axis.

In the second time period T2, the meter-side smart modem 32 may operate as a master device, and the group of legacy meters 20 may operate as slave devices. That is, in the second time period T2, the meter-side smart modem 32 can control the group of legacy meters 20.

The setting of the first time period T1 and the second time period T2 is led by the fourth network interface 324, that is, the meter-side smart modem 32, and the group of smart meters 40 and the group of legacy meters 20 are subject to the control of the smart modem 32 on the meter side.

In one embodiment, the setting of the first time period T1 and the second time period T2 is performed by the meter-side smart modem 32, and the specific operation of the meter-side smart modem 32 is performed by the DCU. may be controlled by

In the first time period T1, the group of smart meters 40 communicate with the smart modem 32 at the meter side according to a predetermined rule. Since the group of smart meters 40 and the smart modem 32 on the meter side can be designed to satisfy the new RS485 MAC protocol, there is no problem in communication in the first time interval T1. The predetermined rule may be referred to herein as a first local communication protocol, and in one embodiment, it may specifically be a CSMA/(CA+CD) protocol.

In this case, each of the group of smart meters 40 may be provided with a network interface 411 supporting the RS485 MAC protocol. The network interface 411 may include an RS485 MAC 4100.

For example, among the group of smart meters 40, the first smart meter 41, the second smart meter 42, and the third smart meter 43 have MAC addresses 4101 for communication with the first meter, and the second smart meter 4101, respectively. A MAC address 4102 for meter communication and a MAC address 4103 for third meter communication may be allocated.

In the second time period T2, the group of legacy meters 20 may appear as if the meter-side smart modem 32 operates in the same way as the legacy modem 12 shown in FIG. 1. there is.

The payload of the communication packet flowing through the local communication medium 81 includes the HDLC packet 510 itself transmitted by the DCU 1 to the meter-side smart modem 32 through the DCU-side smart modem 31. , or a packet in which the HDLC address is modified from the HDLC packet 510 may be included.

In the first time interval T1, the smart modem 32 at the meter side and the group of smart meters 40 may communicate with each other according to a first local communication protocol among the RS485 MAC protocols. The meter-side smart modem 32 includes the HDLC packet 510 in the payload of the meter coexistence communication packet following the RS485 MAC protocol in the first time period T1, so that the group of smart meters (40) can be forwarded.

In the second time interval T2, the meter-side smart modem 32 and the group of legacy meters 20 may communicate with each other according to the HDLC communication protocol. The meter-side smart modem 32 may directly deliver the HDLC packet 510 to the group of legacy meters 20 through the local communication medium 81 in the second time period T2.

<Management of HDLC address for smart meter/legacy meter>

Different HDLC addresses are assigned to each of the smart meter 40 and each of the legacy meter 20 connected to the fourth network interface of the smart modem 32 of one meter side.

In one embodiment, the lower two digits (LS) of the serial number (S) following the decimal system of the smart meters 40 and legacy meters 20 locally connected to the smart modem 32 on the side of one meter are mutually exclusive. can be a different value. This guarantee of different values can be made by manually checking the smart meters 40 and the legacy meters 20 by a person installing the smart modem on the one meter side.

In one embodiment, up to 100 smart meters 40 and legacy meters 20 locally connected to one meter-side smart modem may exist. In another embodiment, a total of up to 32 smart meters 40 and legacy meters 20 locally connected to one meter-side smart modem may exist.

However, when different meter-side smart modems are given, that is, when the first meter-side smart modem and the second meter-side smart modem are given, the smart meter or legacy meter locally connected to the first meter-side smart modem The assigned HLDC address may overlap with the HLDC address assigned to a smart meter locally connected to the smart modem of the second meter or to a legacy meter.

In one embodiment, the smart modems 31 and 32 do not report to the DCU 1 details of message exchanges with the smart meters 40 and legacy meters 20, and only the DCU 1 Only the information requested by the smart modems 31 and 32 needs to be provided to the DCU 1.

One of the differences between the technology according to the present invention and the prior art is that the smart meter 40 is provided with the RS485 MAC 4100 supporting the above-mentioned RS485 MAC protocol, but the legacy meter 20 is not provided with this MAC. point. Even if it is assumed that some kind of MAC is provided to the legacy meter 20, it is a different kind of MAC from the RS485 MAC (4100). The difference is that the media access rules of the smart meter 40 are different from the media access rules of the legacy meter 20 .

When the smart modem 32 on the meter side is initialized by itself, information about the smart meter 40 and the legacy meter 20 connected through the fourth network interface 324 and the local communication medium 81 is time-division described above. Access can be collected through methods. The information may include information about serial numbers of the smart meter 40 and the legacy meter 20 .

In the first time period (T1), each smart meter 40 transmits at least the least significant two digits (LS) of the serial number of the smart meter 40 to the meter side according to the first local communication protocol of the RS485 MAC protocol. It can be transmitted to the smart modem 32.

And in the second time period (T2), each legacy meter 20 transmits at least the least significant 2 digits (LS) of the serial number of the meter 20 according to the conventional HDLC communication protocol to the smart modem 32 on the meter side. ) can be sent to In one embodiment of the present invention, the HDLC communication protocol may be regarded as a second local communication protocol among RS485 MAC protocols.

The smart modem 32 on the meter side generates the HDLC address of each smart meter 40 by including the least significant 2 digits (LS) collected from each smart meter 40, and collects from each legacy meter 20 By generating the HDLC address of each legacy meter 20 by including the least significant 2 digits (LS), a meter list including information on meters managed by the smart modem 32 on the meter side can be created. The meter list may include the HDLC address of each meter.

<How the meter-side smart modem generates the HDLC address 1>

The meter-side smart modem 32 may generate an HDLC address for each smart meter 40 by adding a first number to the least significant 2 digits LS collected from each smart meter 40, and the meter The side smart modem 32 may generate an HDLC address for each legacy meter 20 by adding a second number to the least significant two digits LS collected from each legacy meter 20 . Here, the first number and the second number may be different numbers. In this way, the least significant 2 digits (LS) of any one legacy meter connected to the smart modem 32 on the meter side and the least significant 2 digits (LS) of another smart meter connected to the smart modem 32 on the meter side Even if are identical to each other, the two HDLC addresses finally generated from them may be different from each other.

The meter-side smart modem 32 may transmit the generated meter list to the DCU 1.

The DCU 1 can perform meter reading by communicating with the meters using the HDLC address included in the meter list as a target address.

<How the meter-side smart modem generates the HDLC address 2>

In one embodiment, the power line communication MAC 3300 shown in FIG. 2 may be divided into a first power line communication MAC 3310 and a second power line communication MAC 3320. That is, the meter-side smart modem 32 may include two MACs for power line communication.

This is the HDLC address for the smart meters 40 when the lower two digits LS of the serial number S of the two or more smart meters 40 connected to the smart modem 32 on the meter side are the same. This is to avoid duplication.

In addition, when the lower two digits (LS) of the serial number (S) of two or more legacy meters (20) connected to the smart modem (32) on the meter side are the same, the HDLC address for the legacy meters (20) This is to avoid duplication.

In addition, when the lower two digits (LS) of the serial number (S) of the smart meter 40 connected to the smart modem 32 on the meter side and the legacy meter 20 are the same, the legacy meter 20 and This is to prevent the HDLC address of the smart meter 40 from being duplicated.

Specifically, the lower two digits (LS) of the serial numbers (S) of the first and second meters selected from among the smart meters 40 and the legacy meters 20 in the smart modem 32 on the meter side It can be assumed that are equal to each other. At this time, if the smart modem 32 on the meter side uses the lower two digits LS as it is, the DCU 1 cannot distinguish the first meter from the second meter.

Therefore, the meter-side smart modem 32 adds the first number extracted from the MAC 3310 for the first power line communication to the lower two digits of the serial number of the first meter to obtain the first HDLC address for the first meter. can create The first HDLC address generated in this way may have a length of 2 bytes or 4 bytes.

Similarly, the meter-side smart modem 32 adds the second number extracted from the MAC 3320 for second power line communication to the lower two digits of the serial number of the second meter to obtain a second HDLC address for the second meter. can create The first HDLC address generated in this way may have a length of 2 bytes or 4 bytes.

In this case, the first number and the second number are different numbers.

The meter-side smart modem 32 may generate a meter list including information on meters managed by the meter-side smart modem 32 . The meter list may include the HDLC address of each meter created as above.

The meter-side smart modem 32 may transmit the generated meter list to the DCU 1.

The DCU 1 can perform meter reading by communicating with the meters using the HDLC address included in the meter list as a target address.

For example, if the DCU 1 transmits a command for performing a meter reading using the first HDLC address included in the meter list as a target address through a power line, the meter-side smart modem 32 receives the first HDLC address from the command. can be extracted. The meter-side smart modem 32 can obtain the lower two digits of the serial number by removing the first number extracted from the first power line communication MAC 3310 from the first HDLC address. At this time, the meter-side smart modem 32 does not remove the second number extracted from the second power line communication MAC 3320 in the process of obtaining the lower two digits of the serial number, and the first power line communication MAC ( 3310), it can be determined that the lower two digits of the serial number belong to the first meter rather than the second meter. Therefore, the meter-side smart modem 32 can perform meter reading for the first meter instead of the second meter based on the command for the DCU 1 to perform meter reading using the first HDLC address as a target address. there is.

In other words, the smart modem 32 on the meter side can know the serial number of the first meter as well as the lower two digits of the serial number of the first meter. In addition, the smart modem 32 on the meter side can know the serial number of the second meter itself as well as the lower two digits of the serial number of the second meter. Therefore, the smart modem 32 on the meter side can create and store a table in which the generated first HDLC address and the second HDLC address correspond to the serial number of the first meter and the serial number of the second meter, respectively. Therefore, the smart modem 32 on the meter side, when the DCU 1 receives a command to perform a meter reading using the first HDLC address included in the meter list as a target address through the power line, the first HDLC address in the table The meter reading for the first meter can be performed using the serial number of the first meter, which is the meter corresponding to .

Since the RS485 MAC (4100) is included in the smart meters (40), even if HDLC addresses between the smart meters (400) are duplicated, when the smart meter (32) scans, two smart meters (400) have duplicate HDLC addresses. The meters 40 may not respond at the same time.

However, since the legacy meters 20 do not include the RS485 MAC 4100, if the HDLC addresses between the legacy meters 20 are duplicated, when the smart meter 32 scans, two HDLC addresses with duplicate HDLC addresses are duplicated. Two legacy meters 20 may respond at the same time, resulting in a collision. Therefore, in one embodiment of the present invention, the collision problem can be solved by inserting an adapter device giving a MAC address according to the RS485 MAC (4100) in front of the RS485 communication terminal of the legacy meter (20).

<Method of time-division automatic weighing meter reading>

4 is a method in which the smart modem 30 collects HDLC addresses of the smart meter 40 and the legacy meter 20 and provides them to the DCU 1 in the time-division automatic metering method provided according to an embodiment of the present invention. is a flow chart showing

In step S10, the meter-side smart modem 32 communicates with the smart meter 40 connected to the fourth network interface 324 of the meter-side smart modem 32 during the first time interval T1. Thus, first data that is at least a part of the serial number of the smart meter 40 can be obtained.

In this case, the first data may be a single digit number or a double digit number in decimal.

At this time, the smart meter 40 may use the first local communication protocol. The first local communication protocol is a communication protocol using a MAC, and may be, for example, a CSMA/(CA+CD) protocol.

In step S20, the meter-side smart modem 32 is a legacy meter connected to the fourth network interface 324 during a second time period T2 that does not overlap with the first time period T1 ( 20) to acquire second data that is at least a part of the serial number of the legacy meter 20.

In this case, the second data may be a single digit number or a double digit number in decimal.

At this time, the legacy meter 20 may use the second local communication protocol. The second local communication protocol is a communication protocol that does not use a MAC according to the above-described first local communication protocol, and may be, for example, an RS485 protocol and/or an HDLC protocol.

In step S30, the meter-side smart modem 32 generates a first code including the first data, stores the first code as an HDLC address of the smart meter 40, and A second code including data may be generated and the second code may be stored as the HDLC address of the legacy meter 20 .

In this case, the first code and the second code may each have a size of 1 byte or 2 bytes.

In step S40, the smart modem 32 on the meter side generates an HDLC address list including the HDLC address of the smart meter 40 and the HDLC address of the legacy meter 20, and the generated HDLC address The power line communication packet 610 including the list may be transmitted to the DCU 1 through the third network interface 323 of the smart modem 32 at the meter side.

In this case, the third network interface 323 may be an interface connected to power line communication media.

At this time, the power line communication packet 610 transmitted through the third network interface 323 is received by the DCU side smart modem 31, and the DCU side smart modem 31 sends the power line communication packet 610 The included HDLC address list may be transmitted to the DCU 1.

At this time, the DCU 1 communicates with the legacy meter 20 or the smart meter 40 having the HDLC address included in the HDLC address list according to the HDLC protocol, thereby enabling the legacy meter 20 or the smart meter Measurement meter reading information from the meter 40 may be acquired.

5 is a time-division automatic meter reading method provided according to an embodiment of the present invention, in which the smart modem 30 receives an automatic meter reading command packet from the DCU 1 and collects metering information accordingly. This is a flow chart showing how to provide one result back to the DCU.

In step S110, the meter-side smart modem 32 receives the power line communication packet 610 including the HDLC packet 310 generated by the DCU 1 through the third network interface 323. can do.

In step S120, the meter-side smart modem 32 determines whether the first meter having the HDLC address included in the HDLC packet 310 is the smart meter 40 or the legacy meter 20. can judge

In step S130, the meter-side smart modem 32 may transmit the HDLC packet 310 to the first meter through the fourth network interface 324.

At this time, the meter-side smart modem 32 transmits the HDLC packet 310 during the time period classified as the first time period T1 when it is determined that the first meter is the smart meter 40. It is intended to be transmitted to the first meter. At this time, the meter-side smart modem 32 may use the first local communication protocol to transmit the HDLC packet 310 .

On the contrary, when it is determined that the first meter is the legacy meter 20, the meter-side smart modem 32 transmits the HDLC packet 310 during the time period classified as the second time period T2. It is configured to transmit to the first meter. At this time, the meter-side smart modem 32 may use the second local communication protocol to transmit the HDLC packet 310 .

In step S140, the meter-side smart modem 32 may receive a response message to the HDLC packet 310 from the first meter through the fourth network interface 324.

At this time, the meter-side smart modem 32, when it is determined that the first meter is the smart meter 40, transmits the response message to the first meter during the time period classified as the first time period T1. is intended to be received from At this time, the meter-side smart modem 32 may use the first local communication protocol to receive the response message. At this time, the first meter, which is the smart meter 40, is also configured to provide the response message during the time period classified as the first time period T1.

Conversely, when it is determined that the first meter is the legacy meter 20, the meter-side smart modem 32 transmits the response message to the first meter during the time period classified as the second time period T2. is intended to be received from At this time, the meter-side smart modem 32 may use the second local communication protocol to receive the response message. At this time, the first meter, which is the legacy meter 20, is also configured to provide the response message during the time period classified as the second time period T2.

In step S150, the meter-side smart modem 32 may search for the HDLC address of the first meter from the HDLC address list and generate a second HDLC packet using the searched address.

In step S160, the meter-side smart modem 32 generates a third power line communication packet including the second HDLC packet, and transmits the generated third power line communication packet to the fourth network interface 324. through the power line communication media.

At this time, the MAC address for power line communication included in the generated third power line communication packet may be the MAC address of the DCU-side smart modem 31 connected to the DCU 1 .

At this time, the DCU-side smart modem 31 extracts the second HDLC packet from the third power line communication packet and provides it to the DCU 1.

<RS485 MAC protocol according to an embodiment of the present invention>

Hereinafter, operating characteristics of the RS485 MAC protocol according to an embodiment of the present invention will be described in detail. The RS485 MAC protocol uses CSMN (CA+CD) protocol and TDMA. TMDA can be used to support the operation of legacy meters. By using the RS485 MAC protocol, it is possible to solve a collision problem caused by a plurality of identical HDLC addresses existing in the RS485 network. If a conventional legacy meter does not support transmission of a meter event in a push method, a smart meter using the RS485 MAC protocol according to the present invention can transmit a meter event frame in a push method. In addition, since it supports the operation of a legacy meter in the TMDA method, it can support a mode compatible with a legacy meter with a speed of 9600bps.

In one embodiment of the present invention, the DCU 1, that is, the gateway may support a manual/automatic mode selection function. That is, the smart DCU according to the present invention developed from the legacy DCU may operate in the advanced mode, or may be configured in the smart DCU to operate in the same manner as the legacy DUC.

In one embodiment of the present invention, a manual/automatic mode selection function may be supported in a smart meter. A smart meter can also choose to operate as a smart meter or as a legacy meter.

The smart meter according to an embodiment of the present invention supports a speed of 115,200 bps, and can support the use of 1 start/stop bit and No Parity.

The time for a smart meter to transmit 1 byte at 115,200 bps is 86.8 usec, but the time for a legacy meter to transmit 1 byte at 9,600 bps is 1.04 msec.

<RS485 CSMA/(CA+CD) protocol according to an embodiment of the present invention>

The state of the medium (RS485 network) determined by the physical carrier detection and backoff process is an IDLE state, a BUSY state, and a CONTENTION state as shown in FIG. 6 .

The IDLE state is a state in which the RS485 channel is idle. In this state, frame transmission can be performed immediately without random backoff.

BUSY status is a status in which the RS485 channel is being used.

CONTENTION state is a state in which the RS485 channel is in contention.

In the RS485 MAC protocol, for example, Interframe Space (IFS) is 5 msec, Time Slot Duration is 500 usec, and Max CWS(N) is 256 Time Slots, which may be 128 msec.

7 shows the relationship between the use of RS485 driver TXE / nRXE and transmission and reception modes in the RS485 CSMA / (CA + CD) protocol according to an embodiment of the present invention.

According to the RS485 CSMA/(CA+CD) protocol, a physical carrier detection function can be provided, and thus carrier detection is possible when Rx data is received during reception mode operation. In addition, for collision detection, the transmitter transmits its own transmission frame data and performs a reception operation at the same time, compares the received data with its own transmission data, and determines that it is a collision when data that is not identical to each other occurs. Transmission is stopped, and when a collision occurs, frame retransmission may be performed through a random backoff process in the next contention section.

8 illustrates an example of a structure of a frame according to the RS485 MAC protocol exchanged through a local communication medium provided between a smart modem and a smart meter at the meter side by a first local communication protocol according to an embodiment of the present invention. .

A frame according to the RS485 MAC protocol includes a start flag (SF), total frame length information (LEN) from the start flag to CRC, destination MAC address (DA), sender MAC address (SA), frame control (FC) information , a sequence number (SN), a command field (CMD), data, and the CRC.

9 is a flowchart illustrating a process in which a DCU scans a meter ID based on an RS485 MAC according to an embodiment of the present invention.

In FIG. 9, Master (GW) may be the above-described DCU (1), and Slave N may be a meter. In FIG. 9 , communication between the Master (GW) and the Slave N may actually include the smart modems. As shown in FIG. 9, the DCU (Master, GW) can acquire the meter ID and HDLC address information of the meter belonging to its own network by transmitting a SCAN.Request frame when necessary.

In FIG. 9, meter ID and HDLC address information are returned in response to the SCAN.Request frame transmitted by the DCU 1. However, when the new smart meter is installed and powered on in a network system that is already in operation, the DCU 1 does not know this fact. Therefore, the DCU 1 acquires the meter ID and HDLC address information of the installed new smart meter. (1) cannot transmit the SCAN.Request frame again. In addition, even if the DCU 1 can transmit a new SCAN.Request frame again, a situation occurs in which meter ID and HDLC address information for all meters for which reporting has already been completed are returned again, which is not desirable. Therefore, in this case, as shown in FIG. 10, a smart meter newly added to the network can report the meter ID by itself.

10 illustrates a procedure for a newly added smart meter to report its own meter ID in an operating remote inspection system.

DCU (Master, GW) (1) transmits a beacon (Beacon) periodically over the network after transmitting the SCAN.Request frame. When the smart meter newly added to the network receives the beacon, it can operate to transmit SCAN.Report containing its own meter ID and HDLC address information to the DCU (1).

11 is a timing diagram for explaining a TDMA operation method of the RS485 MAC protocol provided according to an embodiment of the present invention.

In one embodiment, the DCU 1 provides information on the remaining time until the start of the communication period (second time period) for communication with the legacy meter (A / B) and information about the length of the second time period ( C) may be included in the beacon transmitted by the DCU 1 through the power line and transmitted to the smart modems on the meter side. At this time, the meter-side smart modem is a beacon that transmits information (A/B) on the remaining time until the start of the second time period and information (C) on the length of the second time period from the meter-side smart modem. can be included in The beacon transmitted by the smart modem on the meter side may be delivered to the smart meters through the local communication media.

In another embodiment, the meter-side smart modem includes information (A / B) on the remaining time until the start of the communication period (second time period) for communication with the legacy meter and the length of the second time period Information (C) may be included in the beacon transmitted by the smart modem on the meter side. The beacon transmitted by the smart modem on the meter side may be delivered to the smart meters through the local communication media. In this case, the DCU may not be involved in the second time period designated by each meter-side smart modem.

Beacon N shown in FIG. 10 includes information about the time lengths of A and C, and beacon N+1 includes information about the time lengths of B and C.

The DCU can perform a traditional DLMS SCAN operation and meter reading operation after entering the communication time period (second time period) of the legacy meter. In this period (second time period), the smart meter, which is a new RS485 MAC-based meter, can stop communication.

A smart meter based on the RS485 MAC protocol provided according to an embodiment of the present invention can operate in a manual legacy meter mode and an automatic legacy meter mode. The manual legacy meter mode is intended to be used through manual setting and operates as a legacy meter at a speed of 9,600 bps. In the automatic legacy meter mode, the automatic gateway detection function is operated after the RS485 MAC-based gateway, that is, the DCU (1) according to an embodiment of the present invention is connected, and through periodic beacon information from the DCU (1). RS485 MAC meter operation is intended to make decisions.

Using the above-described embodiments of the present invention, those belonging to the technical field of the present invention will be able to easily implement various changes and modifications without departing from the essential characteristics of the present invention. The content of each claim of the claims may be combined with other claims without reference relationship within the scope understandable through this specification.

1-DCUs
20 - Legacy meter
31 - DCU side smart modem
32 - meter side smart modem
40 - smart meter
310 - HDLC Packet
323 - 3rd network interface
424 - fourth network interface
T1 - 1st time interval
T2 - second time interval

Claims (19)

As an automatic meter reading method that supports the coexistence of a legacy meter 20 and a smart meter 40 using a meter-side smart modem 32 operating based on a predefined first protocol based on TDMA,
obtaining, by the smart modem at the meter, first data that is at least a part of a serial number of the smart meter by communicating with the smart meter during a first time period (T1) by the TDMA;
obtaining, by the smart modem at the meter, second data that is at least a part of the serial number of the legacy meter by communicating with a legacy meter during a second time period (T2) by the TDMA;
The meter-side smart modem generates a first code including the first data, stores the first code as an HDLC address of the smart meter, generates a second code including the second data, and stores the first code as an HDLC address of the smart meter. 2 code as the HDLC address of the legacy meter; and
The meter-side smart modem generates a HDLC address list including the HDLC address of the smart meter and the HDLC address of the legacy meter, and sends a first power line communication packet including the generated HDLC address list to the DCU 1. transmitting;
Including,
In the first time period, a first local communication protocol is used, and in the second time period, a master-slave second local communication protocol is used.
The smart meter and the meter-side smart modem operate based on the first local communication protocol in the first time interval;
The legacy meter and the meter-side smart modem operate based on the second local communication protocol in the second time period.
Automatic weighing method. The method according to claim 1, wherein the first local communication protocol is a CSMA/(CA+CD) protocol, and the second local communication protocol is an RS485 protocol. The method of claim 1, wherein the smart meter transmits an event generated in the smart meter to the smart modem of the meter in a push method during the first time interval. The automatic meter reading method according to claim 1, wherein the DCU or the smart modem at the meter side obtains predetermined information from the smart meter through a polling method during the first time period. The method of claim 1, wherein a transmission rate according to the first local communication protocol is greater than a transmission rate according to the second local communication protocol. The method of claim 1, wherein a MAC frame exchanged through a local communication medium provided between the smart modem and the smart meter by the first local communication protocol includes a start flag (SF), a start flag and a CRC. Full frame length information, destination MAC address (DA), sender MAC address (SA), frame control (FC) information, sequence number (SN), command field (CMD), data, and automatic metering, including the CRC inspection method. According to claim 1,
The DCU is configured to transmit a scan request packet (SCAN.REQ) through a power line,
The scan request packet sequentially passes through the power line, the meter-side smart modem, and local communication media provided between the meter-side smart modem and the smart meter to be delivered to the smart meter,
The scan request packet is a broadcast packet in which the MAC address of the sender is the MAC address of the DCU,
The DCU, as a response to the scan request packet, receives a scan response packet (SCAN.RESP) including the ID of the smart meter and the HDLC address of the smart meter from the smart modem on the meter side,
Automatic weighing method. According to claim 7,
The ID of the smart meter is an 11-digit decimal number,
The HDLC address of the smart meter is an address generated by the smart modem on the meter side using the least significant two digits of the 11-digit decimal number.
Automatic weighing method. The method according to claim 1, wherein the DCU is a gateway. According to claim 7,
The meter-side smart modem is configured to periodically transmit a beacon,
If the smart meter has never transmitted the scan response packet as a response to the scan request packet, the smart meter responds to the beacon with a scan response packet including the ID of the smart meter and the HDLC address of the smart meter ( SCAN.RESP), and
The beacon is a broadcast packet in which the MAC address of the sender is the MAC address of the smart modem on the meter side.
Automatic weighing method. According to claim 1,
The meter-side smart modem is configured to periodically transmit a beacon during the first time period through a local communication medium provided between the meter-side smart modem and the smart meter,
Each of the beacons includes information about the remaining time until the start of the second time period and the total length of the second time period,
The smart meter is configured to enter a mode in which communication of the legacy meter is not disturbed during the second time period based on information included in the beacon.
Automatic weighing method. According to claim 1,
The smart meter and the legacy meter are connected to a fourth network interface 424 of the smart modem on the meter side,
The first power line communication packet is to be transmitted to the DCU through the third network interface 323 of the smart modem on the meter side;
The third network interface is an interface connecting to power line communication media,
Automatic weighing method. According to claim 1,
The first power line communication packet is received by the DCU-side smart modem 31, and the DCU-side smart modem transmits the HDLC address list included in the first power line communication packet to the DCU,
The DCU acquires meter reading information from the legacy meter or the smart meter by performing communication according to the HDLC protocol with the legacy meter or the smart meter having the HDLC address included in the HDLC address list,
Automatic weighing method. According to claim 1,
receiving, by the meter-side smart modem, a second power line communication packet including the HDLC packet 310 generated by the DCU;
determining, by the smart modem at the meter, whether a first meter having an HDLC address included in the HDLC packet is the smart meter or the legacy meter, using the HDLC address list; and
transmitting, by the smart modem at the meter side, the HDLC packet to the first meter;
Including more,
Automatic weighing method. According to claim 14,
When it is determined that the first meter is the smart meter, the meter-side smart modem transmits the HDLC packet to the first meter using the first local communication protocol during the time period classified as the first time period. is supposed to do,
When it is determined that the first meter is the legacy meter, the meter-side smart modem transmits the HDLC packet to the first meter using the second local communication protocol during a time period classified as the second time period. supposed to do,
Automatic weighing method. According to claim 14,
receiving, by the smart modem at the meter, a response message to the HDLC packet from the first meter;
searching, by the smart modem for the meter, the HDLC address of the first meter from the HDLC address list, and generating a second HDLC packet using the searched address; and
generating, by the meter-side smart modem, a third power line communication packet including the second HDLC packet, transmitting the generated third power line communication packet to a power line communication medium, and transmitting the generated third power line communication packet to the DCU;
Including more,
Automatic weighing method. According to claim 16,
The MAC address for power line communication included in the generated third power line communication packet is the MAC address for power line communication of the DCU-side smart modem 31 connected to the DCU,
The DCU-side smart modem extracts the second HDLC packet from the third power line communication packet and provides it to the DCU.
Automatic weighing method. According to claim 16,
When it is determined that the first meter is the smart meter, the meter-side smart modem receives the response message to the first meter using the first local communication protocol during the time period classified as the first time period. is supposed to do,
When it is determined that the first meter is the legacy meter, the meter-side smart modem receives the response message to the first meter using the second local communication protocol during a time period classified as the second time period. supposed to do,
Automatic weighing method. 13. The method of claim 12, wherein the fourth network interface includes a MAC that is used only during the first time interval and uses the first local communication protocol.

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