REMOTE ACCESS TO ELECTRONIC METERS USING A TCP/IP PROTOCOL SUITE

Abstract: An electronic meter incorporates a TCP/IP protocol suite and an HTTP server (24) to provide two-way access to the meter incorporated into a gateway (20) serving multiple meters connected through a power line or wireless two-way network. The gateway (20) may incorporate an HTTP server (24) for accessing data from multiple meters (40) and for transmission of data to individual meters (40). Other aspects of the disclosed system include the use of a common gateway interface (26) for remote access to meter data and to set meter parameter using HTML forms in HTTP browsers; remote reading and setting of multiple meter parameters using a TCP/IP protocol suite; a TCP/IP protocol suite implemented in designated notes in a CEBus LAN (42) with remote access through TCP/IP (43) to routers and broutes and to individual meters on the LAN; and a SLIP-PPP (21) enabled gateway for remote TCP/IP access (22) through a serial interface to a single or multiple meter parameters.

Description: REMOTE ACCESS TO ELECTRONIC METERS USING A TCP/IP PROTOCOL SUITE FIELD OF THE INVENTION The present invention relates generally to electronic meters and automatic meter reading, and more particularly to TCP/lP-enabled electronic meters for remote two-way access over local area networks and wide area networks . BACKGROUND OF THE INVENTION The present invention relates to automatic meter reading (AMR) systems for use in automatically reading electrical energy and other utility meters (e.g., water and gas meters) . The invention is more particularly intended for, although not limited to, use in an electronic meter. Further background information on electronic meters can be found in U.S. Patent No. 5,548,527, August 20, 1996, titled "Programmable Electrical Energy Meter Utilizing a Non-Volatile Memory" (assigned to ABB Power T&D Company Inc.) Further background on automatic meter reading systems can be found in U.S. Patent No. 5,553,094, September 3, 1996, titled "Radio Communication Network for Remote Data Generating Stations . " - 2 - SUMMARY OF THE INVENTION The present invention, as discussed in greater detail below, involves the use of a TCP/IP protocol suite and a hypertext transfer protocol (HTTP) server. The terms "HTTP" and "TCP/IP" are well known in the networking and telecommunications arts. For example, TCP/IP refers to a well known set of protocols for linking dissimilar devices across networks. The invention also involves the use of a "gateway" . A gateway is a node in a network that connects two otherwise incompatible networks. Gateways may perform code and protocol conversion processes. A "protocol" is a set of rules or procedures relating to the format and timing of data transmissions between two devices. Protocols typically break a file into equal-size blocks or packets. These are sent and the receiving device uses a mathematical procedure to determine whether the block or packet was received accurately. An electronic metering system in accordance with the present invention comprises a wide area network (WAN) operating in accordance with a TCP/IP protocol; a local area network (LAN) comprising a plurality of meters each of which includes meter electronics for measuring a prescribed quantity supplied by a utility and memory for storing measured data and meter control parameters ; a gateway operatively coupled to the LAN and the WAN; and an HTTP server operatively coupled to the LAN and the gateway, whereby the WAN is provided remote access to the measured data and control parameters of the meters . Presently preferred embodiments of the invention further include a CGI application coupled to the HTTP server for use in accessing the measured data. Alternatively, the inventive system may include a virtual machine coupled to the HTTP server for use in accessing the data. The prescribed quantity is preferably electricity, water or gas. - 3 - The HTTP server and CGI application may be embedded in each of the meters or, alternatively, embedded in the gateway. Other features of the present invention are disclosed below. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 schematically depicts an AMR network comprising a wide area network 10, gateway 20, local area network 30 and meters 40, in accordance with the present invention. Figure 2 schematically depicts an embodiment of the present invention in which an HTTP server and a common gateway interface are located in the meter (s) 40. Figure 3 schematically depicts an embodiment of the present invention in which an HTTP server and a common gateway interface are located in the gateway 20. Figure 4 illustrates how the common gateway interface could be replaced by a Java virtual machine and a Java applet . Figure 5 portrays an embodiment of the invention in which one or more computers are given access to the meters by way of a PPP server or interface. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The present invention, in one embodiment, employs an electronic meter incorporating a TCP/IP protocol suite and an HTTP server for two-way access to the meter data. In another embodiment of the invention, the TCP/IP protocol suite is incorporated into a gateway serving multiple meters connected through a power line or wireless two-way network. The gateway employed in a second embodiment of the present invention incorporates an HTTP server for accessing data from multiple meters and for transmission of data to individual meters . - 4 - The basic architecture of the present invention is shown in Figure 1. As mentioned, embedding an HTTP server and a TCP/IP protocol stack within a meter 40 or a gateway 20 to multiple meters through a local area network (LAN) 30 enables remote access to meter parameters on a continuous basis. As shown, a set of N meters 40 communicate through a non-TCP/IP type of LAN 30. The LAN 30 may be, e.g., a CEBus network employing power line or radio frequency communications (the Consumer Electronics Bus (CEBus) protocol has been adopted as an Electronics Industry Association standard (EIA IS-60) , and defines a LAN that uses multiple media, including power line, radio, twisted pair, coaxial cable, and infrared signaling) . Also connected to the LAN 30 is a gateway 20 that is also connected to a TCP/IP wide-area network (WAN) 10. Other applications (not shown) are also connected to the TCP/IP WAN 10 and may need to access the individual meters or groups of meters. These applications access individual meters by sending commands contained in packets with attached TCP/IP destination addresses that are unique to each meter. In the first implementation of the invention (Figure 2) , the gateway 20 receives packets from other applications on the WAN 10. The gateway 20 includes a TCP/IP interface 22 and a LAN interface 28. The LAN interface 28 includes software for transforming the data packets into the format required for transmission on the LAN 30. The gateway 20 then transmits these reformatted packets over the LAN 30 to the meters 40. The steps involved in this transformation are: 1. The gateway examines the TCP/IP address of the packet and determines if it is the address of a meter or meters within the set attached to the gateway through its LAN. If not, the packet is ignored. - 5 - 2. If the packet is intended for one of the meters on the gateway's LAN, the gateway examines the meter TCP/IP address attached to the packet and determines if it is an individual meter address or a broadcast address. 3. If the packet is addressed to an individual meter, then the gateway encapsulates the packet into a larger packet that is addressed to the meter using its unique LAN address (which is different from its TCP/IP address) . 4. If the packet is meant for broadcast to all the meters, then the gateway encapsulates the packet into a larger packet addressed to the special broadcast address of the LAN (which is different from the TCW broadcast address) . 5. If the packet is larger than the maximum allowable packet size for the LAN, then the gateway segments the packet into smaller pieces. Each piece is labeled with the same LAN address as the original, larger packet. 6. Each piece of the segmented packet is transmitted onto the LAN for reception by one or more of the meters. The gateway is responsible for receiving acknowledgments of packet receptions from the meters, and for retransmitting packets if they are not received. Each individual meter listens on the LAN for packets. A meter reconstitutes the original TCP/IP WAN packet from one or more LAN packets, and then executes the commands contained in the packet and sends the results back to the gateway. The steps involved in this process are: 1. The meter examines the LAN address of the packet to see if it is intended for this meter or is a broadcast address. If the address is neither of these, the meter ignores the packet . 2. If the packet is specifically addressed for the meter, an acknowledgment of reception is sent back to the gateway. If an error is found in the packet, a negative acknowledgment is sent back to the gateway. For broadcast transmissions, no acknowledgment is sent. 3. The received packet is appended to any previously received pieces of the larger segmented packet. When all of the pieces of the segmented packet are received, the entire original TCP/IP packet is extracted and sent to the TCP/IP interface software, in the meter. 4. The TCP/IP interface software examines the packet to see what service is being requested. In this case, assume the packet is intended for servicing by the HTTP server. (It is possible that there could be other servers running on the meter to which TCP/IP messages could be sent . ) 5. The HTTP server examines the data packet to see what operation is being requested. In this case, assume that the packet contains a request that an application program be run on the meter to extract its current reading and send it back to the originator of the request. The HTTP server will initiate this application through the Common Gateway Interface (CGI) . 6. The CGI application will query the meter application software to find the current reading. The meter application directly accesses the meter electronics to get the required information. The reading is passed back to the CGI application, which writes the reading into a message using HTML. The HTML message is sent back lo the HTTP server . 7. The HTTP server encodes the HTML message as a TCP/IP packet and sends it on to the meter's TCP/IP interface. 8. The meter's TCP/IP interface sends the packet to the gateway using the same set of steps that the gateway used to send the original request to the meter. - 7 - 9. Once the gateway receives the TCP/IP packet from the meter, it retransmits the packet onto the WAN where the originating application for the command can receive it. In the second embodiment of the invention (Figure 3) , the gateway assumes most of the tasks assigned to the meters in the first embodiment (Figure 2) . The HTTP server 24 and CGI application 26 are moved to the gateway 20, and the meters retain only their interface 42 to the non-TCP/IP LAN. The processing of packets received from the WAN 10 proceeds as follows: 1. The gateway examines the TCP/IP address of the packet and determines if it is the address of a meter or meters within the set attached to the gateway through its LAN. If not, the packet is ignored. 2. The TCP/IP interface software examines the packet to see what service is being requested. In this case, assume the packet is intended for servicing by the HTTP server now contained in the gateway. (It is possible that there could be other server applications running on the meter to which TCP/IP messages could be sent.) 3. The HTTP server examines the data packet to see what operation is being requested. In this case, assume that the packet contains a request that an application program be run to get the current reading of an individual meter and send it back to the originator of the request. The HTTP server will initiate this application through the CGI (26) . 4. The CGI application 26 now runs within the gateway. It must determine the LAN address of the specified meter and send a command packet to it over the LAN. 5. The command is received by the meter and causes the meter application to query the electronics to find the current reading. - 8 - 6. The meter reading is encapsulated into a LAN packet and sent back to the gateway. 7. The CGI application receives the LAN packet from the meter and extracts the meter reading. The reading is written into an HTML message and is sent back to the HTTP server. 8. The HTTP server encodes the HTML message as a TCP/IP packet and sends it on to the gateway's TCP/IP interface 22. 9. The gateway's TCP/IP interface 22 sends the packet onto the WAN 10 where the originating application for the command can receive it . Both implementations of the present invention have been described as using CGI applications 46, 26 to handle the details of accessing the current reading for a meter. As shown in Figure 4, the CGI application could be replaced by a Java virtual machine (VM) 26' running a Java application 26'' that performs the same operations as the CGI application. In addition, both implementations have been described using an example where the current reading of an individual meter is requested by an application connected to the WAN . An application on the WAN can also write data to a meter or meters using similar procedures . The data could modify parameters affecting the operations of the meter or meters . An example would be rate updates . Either implementation, with their use of TCP/IP and HTTP servers, supports the reading of meters or setting their parameters using browsers such as a Netscape™ or Explorer™. Utilities and homeowners could perform remote on-demand meter reading via their browsers . An individual meter or group of meters could be accessed as if the meter (s) were a web site and their current readings or other data could be displayed on the browser. The meters could - 9 - send forms to the browser that the user could fill in to change parameters in the meters . Both reading and updating the meters would be protected by encryption and passwords. As shown in Figure 5 , a browser could gain access to the meters through a phone line to a Point-to-Point Protocol (PPP) server 60 attached to the WAN 10 or attached directly to a gateway 20. The PPP server interfaces with modems (not shown) to provide a TCP/IP link to a browser on the other end of the line. The PPP server sends the packets from the phone line onto the WAN where they are received by the appropriate gateway. In the case of a phone line connection directly to a gateway, the PPP software includes an interface 21 for directly connecting to the TCP/IP WAN interface 22 so that the packets received over the phone line are handled in the same way as packets received over the WAN 10. The browser may be replaced by an intelligent application program that accesses the HTTP server for automated meter reading and parameter setting on a scheduled and repetitive basis. The application uses the meter readings to create or update records in a database. This application could be a Java application which can interact with the HTTP servers and databases that support the HTTP protocols . In sum, the present invention includes the following novel aspects: (1) Embedded HTTP server in a meter for on-demand access to meter data and for remotely setting meter parameters; (2) Embedded HTTP server in a gateway to multiple meters to read and set parameters in individual meters on a LAN; (3) Using CGI for remote access to meter data and to set meter parameters using HTML forms in HTTP browsers; (4) Remote reading and setting of multiple meter parameters using TCP/IP protocol suite; (5) TCP/IP protocol suite implemented in designated nodes in a CEBus LAN including CEBus routers and brouters with remote access - 10 - through TCP/IP to the router/brouter and, therefore, individual meters on a LAN; (6) SLIP-PPP enabled gateway for remote TCP/IP access through a serial interface (phone line, or ISDN, for example) to a single or multiple meter parameters (setting and reading) . The foregoing detailed description of preferred embodiments of the invention is not meant to limit the scope of protection of the following claims. Those skilled in the art of electronic metering will recognize that many modifications may be made to the presently preferred and specifically described embodiments without departing from the true spirit of the invention.

Claims: - 11 - We claim: 1. An electronic metering system, comprising: (A) a wide area network (WAN) operating in accordance with a TCP/IP protocol; (B) a local area network (LAN) comprising a plurality of meters each of which includes meter electronics for measuring a prescribed quantity supplied by a utility and memory for storing measured data and meter control parameters; (C) a gateway operatively coupled to said LAN and said WAN; and (D) an HTTP server operatively coupled to said LAN and said gateway, whereby said WAN is provided remote access to said measured data and control parameters of said meters. 2. A system as recited in claim 1, and further comprising a common gateway interface (CGI) application coupled to said HTTP server for use in accessing said measured data. 3. A system as recited in claim 1, and further comprising a virtual machine coupled to said HTTP server for use in accessing said data. 4. A system as recited in claim 1, wherein said prescribed quantity is electricity. 5. A system as recited in claim 1, wherein said prescribed quantity is gas. 6. A system as recited in claim 1, wherein said prescribed quantity is water. - 12 - 7. A system as recited in claim 2, wherein said HTTP server and CGI application are embedded in each of said meters . 8. A system as recited in claim 1, wherein said HTTP server and CGI application are embedded in said gateway. 9. A system as recited in claim 1, wherein each of said meters further comprises a LAN interface. 10. A system as recited in claim 1, wherein said gateway comprises a LAN interface. 11. A system as recited in claim 7, wherein each of said meters further comprises a TCP/IP interface. 12. A system as recited in claim 1, wherein said gateway comprises a TCP/IP interface. 13. A system as recited in claim 1, and further comprising a common gateway interface (CGI) application coupled to said HTTP server for use in accessing said measured data; wherein said HTTP server and CGI application are embedded in each of said meters; wherein said gateway and each of said meters comprises a LAN interface and a TCP/IP interface; and wherein said prescribed quantity is a member of the group consisting of electricity, water and gas . - 13 - 14. A system as recited in claim 1, and further comprising a common gateway interface (CGI) application coupled to said HTTP server for use in accessing said measured data; wherein said HTTP server and CGI application are embedded in said gateway; wherein each of said meters and said gateway comprises a LAN interface; wherein said gateway further comprises a TCP/IP interface; and wherein said prescribed quantity is a member of the group consisting of electricity, water and gas. 15. A system as recited in claim 1, wherein said LAN is a CEBus LAN. 16. A system as recited in claim 13, wherein said LAN is a CEBus LAN. 17. A system as recited in claim 14, wherein said LAN is a CEBus LAN.

Inventors: ARDALAN SASAN H, VAN DEN BOUT DAVID E, ARDALAN, SASAN, H., VAN DEN BOUT, DAVID, E.
Applicants: ABB POWER T & D CO, ABB POWER T & D COMPANY INC.
Application year: 1998
Main classification: G08C13
IPC codes: G08C15, H04L29, H04M11