MXPA00002005A - Electronic electricity meter - Google Patents

Abstract

An electronic electricity meter which, in one embodiment, includes a modem board, or unit, coupled to the meter microcomputer (20) and exchanges information between the meter (10) and a central computer (58) is described. Using signals supplied by the meter microcomputer (20) and the central computer (58), the modem unit (50) microcomputer can determine whether to exchange information between the meter and the central computer (58) and the proper time at which the information should be exchanged. In an exemplary embodiment, the modem unit (50) detects various conditions within the meter and responds by exchanging information with the central computer (58) at a proper, or pre-defined, time. The modem unit has two different basic modes, or states, of operation. These states of operation are sometimes referred to as the call originate mode and the call answer mode. Call originate refers to the mode of the unit when a condition occurs in meter 10 and information is being transmitted to the central computer (58) from the modem unit (50) utilizing a telephone line. The call is originated upon occurrence, for example of a power outage to the meter. In the call answer mode, the central computer originates a call to the meter. The central computer (58) can then transfer information to the meter, for example a new program can be stored in the modem unit memory.

Description

ELECTRONIC ELECTRICITY METER REFERENCE TO THE RELATED APPLICATION This application claims the benefit of the United States Provisional Application of the United States of America No. 60/091, 039, filed on June 29, 1998. BACKGROUND OF THE INVENTION This invention relates generally to electricity measurement and more particularly, to an electronic electricity meter that can be configured to transmit information to a central computer via a modem unit. In many electronic electricity meters, communications with a microcomputer of the meter can be made via an optical port or an option board connector. For example, in some known meters, an electrical connector is provided so that several options boards, such as a telephone modem communications board, can be electrically connected to the meter's microcomputer. A central computer is commonly used to collect data, including billing information, from the meter, using the modem communication board. The data is available from the modem communication board in a predefined format (a protocol defined by ANSI) in the communications channel that connects the connector of the options board to the meter's microcomputer. To reduce the number of common annoyances and events, for example, power interruption calls, it is desirable to provide a modem unit, or board, that detects the conditions inside the meter and exchanges information with the central computer after the condition has existed for a previously defined period of time. It would also be desirable to provide a unit that would allow modification of the operating parameters. Additionally, it would be desirable to provide a modem unit that could be easily and quickly attached to a meter while allowing the programming of a security password. BRIEF DESCRIPTION OF THE INVENTION In an exemplary embodiment, an electricity meter includes a modem circuit, or unit, coupled to the meter's microcomputer that exchanges information between the meter's microcomputer and a central computer of the data source. Using the signals supplied by the meter's microcomputer and the central computer, the modem unit can detect various conditions within the meter and determine the appropriate time to exchange the information. In one embodiment, the modem unit includes a microcomputer having a plurality of timers. In one aspect, the present invention is directed to allow the programming of modem and meter unit passwords. Specifically, the modem unit and the meter are placed in a password recovery state upon detecting the closure of an external switch. The closing of the external switch simultaneously places the meter and the modem unit in password recovery states so that new passwords can be programmed into the meter and modem unit via the central computer. This configuration avoids the time and expense associated with re-programming the modem unit in the meter workshop or having to send a specially trained individual to the meter location to perform reprogramming. In another aspect, the present invention is directed to limit the number of calls initiated from the meter. More specifically, the microcomputer of the modem unit detects certain events and waits for a pre-defined period of time before initiating the call to the central computer. In one form, after the modem unit detects a power interruption indicator from the meter's microcomputer, the modem unit waits for a period of time that can be programmed before making an interrupt call to the central computer. The microcomputer of the modem unit can be additionally configured so that in order for the call to the central computer to be initiated, several conditions must occur in a previously defined period of time. If all events do not occur within the specified time period, the call will not be made to the central computer. In still another aspect, the present invention relates to the modem unit answering calls from the central computer. More specifically, and in accordance with one embodiment, the meter modem unit receives new program information from the central computer. The program of the microcomputer of the modem unit is stored in a non-volatile memory that has two segments. A new program is stored in an active segment of the memory while the microcomputer of the modem unit executes a program of the active segment. If the programming is complete, the microcomputer changes the inactive segment to the active segment and executes the new program. However, if the programming is not completed, the modem unit's microcomputer will continue to execute the program stored in the active segment. The two segments ensure that the meter will not be left in a partially programmed mode. In a further aspect, the present invention relates to using multiple meter in a subordinate master configuration. The information is exchanged between the meters and the central computer using a single telephone line. More specifically, each meter includes a modem unit that has a unique identification number. Prior to the exchange of information from the central computer, an identification number is transferred to the meters. Each microcomputer in the meter determines if the ID number transferred is equal to the identification number stored in its memory. If the numbers are the same, that modem unit exchanges information with the central computer. Meters whose ID number is not transferred are waiting and listening to the next ID number transferred to determine if there is a similarity. The modem unit described above detects multiple conditions and responds to those conditions in the previously defined time appropriate to reduce the number of calls of common events and inconvenience. The new operation parameters can also be transferred to the modem unit to allow modification of the time and condition parameters. The modem unit described above allows the password to be reprogrammed and the user does not have to previously program the modem unit. As a result, a new modem unit can be quickly installed in a meter. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of an electronic energy meter. Figure 2 is a block diagram of a modem unit in accordance with an embodiment of the present invention.

Figure 3 is a flow chart of the operation of the meter in accordance with an embodiment of the present invention.

Figure 4 is a flow chart illustrating a sequence of process steps for detecting a condition in an electronic electricity meter. Figure 5 is a flow chart illustrating a sequence of process steps for detecting a password recovery status in an electronic electricity meter. Figure 6 is a flow chart illustrating a sequence of process steps for detecting an energy interruption state in an electronic electricity meter. Figure 7 is a flow diagram illustrating a sequence of process steps for detecting an interrupt call in an electronic electricity meter. Figure 8 is a flow chart illustrating a sequence of process steps for generating a status report on an electronic electricity meter. Figure 9 is a flow chart illustrating a sequence of process steps for the responding state called in an electronic electricity meter. Figure 10 is a block diagram of a master / slave configuration in accordance with one embodiment of the present invention. Figure 11 is a flow diagram illustrating a sequence of process steps for a master / slave configuration of an electronic electricity meter. DETAILED DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram illustrating an electronic energy meter 10 which, for example, is commercially available from General Electric Company, 130 Main Street, Somersworth, N. H. 03878, and generally referred to as the KV meter. The KV meter can be modified to incorporate the modem unit described below in more detail. Although the present apparatus and methods are described herein in the context of an electronic electricity meter, it should be understood that the present invention is not limited to practicing with any particular meter. The present invention can be used in relation to other meters based on microcomputers. Referring now specifically to Figure 1, the meter 10 includes voltage sensors 12 and current sensors 14. Sensors 12 and 14, in operation, are commonly coupled to power lines that supply power to the site in which it is located the meter The sensors 12 and 14 are coupled to an analog-to-digital (A / D) converter 16 that converts the analog input current and voltage signal to digital signals. The output of the converter 16 is provided to a digital signal processor (DSP) 18. The digital signal processor 18 supplies the microcomputer with 20 digitized measurement quantities, for example, V2H, l2H. The microcomputer 20, using the measurement quantities provided by the digital signal processor 18, performs the additional calculations and measurement functions. The digital signal processor 18 may, for example, be a commercially available processor as Model Number TMS320 from Texas Instruments Company, P.O. Box 6102, Maíl Station 3244, Temple, TX 76503, modified to perform measurement functions. The microcomputer 20 is coupled to a liquid crystal display 22 to control the deployment of various selected measurement quantities and for an optical communications port 24 to allow an external reader to communicate with the microcomputer 20. Port 24 may be the port well known OPTOCOM® from General Electric Company, 130 Main Street, Somersworth, N. H. 03878, which is in accordance with the optical port of ANSI type I I. The microcomputer 20 can also generate additional outputs 26 used for other functions as is well known in the art. The microcomputer 20 can, for example, be an eight-bit microcomputer commercially available from Hitachi America, Inc., Semiconductor &; I. C. Division, Hitachi Plaza, 2000 Sierra Point Parkway, Brisbane, CA 94005-1819, modified to perform measurement functions. The microcomputer 20, in one embodiment, is also coupled to an input / output board (I / O) 28 and a high-performance board 30. Additionally, the microcomputer 20 is coupled, via a control bus 32, to a memory programmable and erasable electronic read only (EEPROM) 34. The input / output board 28 and the high-performance board 30 are also coupled, via the control bus 32, to the programmable read-only memory and erasable so 34. The backup power is provided to the meter 10 by an energy interruption battery 36 coupled to a wide-range power supply 38. In normal operation, when backup power is not required, the power is supplied to the Meter components from the power lines via the power supply 38. Many functions and modifications of the components described above are well understood in the technique of measurement n. The present application is not directed to said functions and modifications included. Rather, the present application is directed to the methods and structures described below in more detail. Additionally, although the methods and structures are described below in the physical equipment environment shown in relation to Figure 1, it should be understood that said methods and structures are not limited to practice in said environment. Methods and structures could be practiced in many other environments. Additionally, it should be understood that the present invention can be practiced with many alternative microcomputers and that it is not limited to the practice in relation to only the microcomputer 20. Therefore, as used herein, the term microcomputer is not limited to to mean only integrated circuits referred to in the art as microcomputers, but broadly refers to microcomputers, processors, microcontrollers, application-specific integrated circuits, and other programmable circuits. Figure 2 is a block diagram of an exemplary modem circuit, or unit, according to an embodiment of the present invention, generally, the unit 50 is coupled to the meter microcomputer 20 as described below with more In detail and at least based in part on the signals present in the unit 50, the unit 50 can determine whether the meter 10 should perform any action as described below. With reference now specifically to Figure 2, the unit 50 includes a microcomputer 52 coupled to the microcomputer of the meter 20, a memory 54, and a modem circuit 56. The unit 50 provides a communication path or link, for exchanging data, or information, between the meter 10 and a central computer 58. The microcomputer 52, includes, in one embodiment, a random access memory (RAM) 60 and a read-only memory (ROM) 62. The programmed parameters and the operation information or data (not shown), are stored in the memory 54. The memory 54 may, for example, be a non-volatile memory device such as an electronically erasable programmable read-only memory (EEPROM), although other types of non-volatile memory may be used. The modem circuit 56 may, for example, be a set of modem integrated circuits commercially available as Model Number RC224AT from Rockwell International Corp., Digital Communications Division, 431 1 Jamboree Road, Newport Beach, CA 92660. Communications data, response and command are exchanged between the microcomputer 52 and the modem circuit 56. A telephone interface circuit 64 is coupled to the modem circuit 56 to a telephone line 66 so the information can be remotely exchanged between the meter 10 and the central computer 58. In one embodiment, the microcomputer of the modem unit includes a timer circuit 80 having a plurality of timing circuits for measuring time. The timer circuit 80 includes a real-time clock 82, an interrupt timer 84, an interrupt delay timer 86, and a call delay timer 88. The real-time clock 82 generates a time value representative of the current date and time, for example, HH: MM: SS, MM / DD / YY. Timers 84, 86, and 88 are used to measure the amount of time that has elapsed since a certain event or occurrence of a condition. The timers 84, 86, and 88 may be programmed with an initial value and may increase or decrease their value and produce a signal when the programmed time has passed or elapsed. In an alternative embodiment, the timer circuit 80 may be separate and distinct from the microcomputer of the modem unit 52. To exchange information between the meter 10 and the central computer 58, and in one embodiment, a data exchange algorithm it is loaded into the modem unit 50. Specifically, the algorithm is loaded, and stored in the memory 62. Then, the algorithm is executed by the microcomputer 52. A flow chart 100 that illustrates the process steps executed by the microcomputer 52 when exchanging information between the meter 10 and the central computer 58 is set forth in Figure 3. More particularly, at the switch 102 of the meter 10, or any time after the power is applied to the meter 10, various parameters 104 are programmed in the memory 54. In one embodiment, the parameters include initial values for the timer circuits 80, specifically, the initialization of the timers 84, 86, and 88, whether an interrupt call should be made, how long the meter 10 should wait before making a call, and whether the meter 10 should answer a call from the central computer 58. Additionally, after that the parameters are programmed and the energy is applied to the meter 10, the interrupt delay timer 86 is started. After programming the parameters 104, the microcomputer 52 monitors the operations of the meter 10 to determine, or detect, whether a condition exists , or if a change 106 has occurred in the signals provided to the modem unit 50. The conditions include an error, caution and diagnostic condition. If a condition 106 is detected, information is transferred or exchanged, using the modem unit 50. Particularly, the microcomputer 52 detects the modifications of the signals provided from the microcomputer of the meter 20 to the microcomputer of the meter 52 and in the signals provided of the central computer 58. More specifically as shown in Figure 4, the microcomputer 56 detects 106 at least the following conditions or changes and exchanges 1 08 the indicated information. Detect Condition 1 06 Information Exchange 1 08 1. Password Recovery 110 Retrieve Password 114. 2. Power Interruption 118 Power Interrupt Call 122. 3. Programmed Status Report 126 State Call 130 4. Computer Call central 134 Answer call 138. 5. New Program 142 Update Program 146. 6. Master / Subordinate Mode 150 Update Master / Subordinate 154 Password Recovery and Password Retrieval Password recovery 1 1 0 and recover password 1 12 refer to detect a state of password recovery and activate the programming of the password of the modem unit 50 and the password of the meter 1 0. In a modality, an external switch, which a user can operate, generates a signal of Password Recovery q ue is provided to the modem unit 50 from the microcomputer of the med. code 20. The Password Recovery signal is provided. to the microcomputer 52 in a low to high state to activate the programming of the passwords. More particularly, and with reference to Figure 5, recovering the password 1 14 includes disabling the security of the password 200 of the modem unit 50 and setting the modem unit 50 to a state of password recovery 202. Deactivate the password 200 allows the microcomputer 52 of the modem unit 50 to continue operating without having a password that matches the meter password. After the modem unit 50 is placed in the recovery state 202, the same password is stored 204 in the meter 10 and the modem unit 50. Specifically, the passwords are transmitted from the central computer 58 to the meter 10 using the unit modem 50. Then, the passwords are programmed into the meter's microcomputer 20 and the memory of the modem unit 54. After performing the programming of the new passwords on the microcomputer 20 and the memory 54, the Password Recovery signal supplied the microcomputer 52 is changed to a false or low status by the microcomputer of the meter 20. The password security of the modem unit 50 is activated 208 after the modem unit 50 receives the new passwords.

For example, if a new modem unit 50 is installed and coupled to a microcomputer 20, the meter password and the modem unit password would not match; therefore, the meter 10 can not be programmed to extend the functionality of the meter 10. As a result of the recovery of the password 14, the modem unit 50 and the microcomputer 20 will have matching passwords. Power interruption and power interruption call Power interruption 1 18 and power interruption call 122 refer to notifying central computer 58 when power is removed from meter 10. A power interruption signal is supplied to the modem unit 50 of the microcomputer of the meter 20 to indicate that the energy has been removed from the meter 10. Specifically, the power interruption signal supplied by the microcomputer 20 changes from a false state, to a true state when the energy is removes from the meter 10. More specifically and as shown in Figure 6, when the microcomputer 52 detects the power interruption 1 18, the power is supplied 220 to the microcomputer 52 from the interruption battery 36. The microcomputer 52 updates 222 a meter status signal that is stored in the memory 54. Then, the interrupt timer is started 224 and the interrupt delay timer is stopped and the value is stored 226 in the memory 54. Then, the value of the interrupt timer 84 is monitored 228 using the microcomputer 54 to determine if the value of the interrupt timer 84 is within one valid range. If the energy is not reset to the meter 10 before the value of the interrupt timer 84 is within the valid range, the microcomputer 52 examines 230 the previous completed parameter of the interrupt call stored in the memory 54 to determine if it should be done an interruption call. If the previous completed parameter of the interrupt call stored in the memory 54 is in a false state, a call 232 is made to the central computer 58 as will be described below. However, if the previous completed parameter of the interrupt call is in a true state, the microcomputer 52 examines 234 the value of the interrupt delay timer 86 stored in the memory 54 to determine whether the value is within a valid range or previously defined If the value is within the previously defined range, a call is made to the central computer 58. However, if the value is out of the valid range, the microcomputer 52 restarts the interrupt delay timer 86 and waits for power to be applied to the meter 10. The interrupt timer 84 and the interrupt delay timer 86 may be configured to avoid annoying interruption calls caused by transient power periods and to alter the timing of interrupt calls of different meters in an interruption area common. Specifically, the interrupt timer 84 may be configured to prevent calls from being made to the central computer 58 until a specific amount of time has passed. In one embodiment, the interrupt timer 84 is programmed with a value between 0, indicating no delay, and 255 seconds. If the value is programmed with a non-zero value, the energy must be removed from the meter 10 for at least that period, or valid range of time, before the microcomputer 52 proceeds. For example, in one embodiment, the diagnostic tests or reviews are delayed for a period of time that can be selected to allow stabilization of providing power to the meter 10. In another embodiment, the calls to the central computer 58 are avoided until the period of time selected for stabilization has transpired. The value of the interrupt timer 84 is altered to avoid generating annoying power interruption calls having a duration of less than the programmed value of the interrupt timer 84. In addition., the interrupt delay timer 86 may be configured to avoid annoying calls of transient conditions. For example, typical interruptions may consist of a series of energy transitions before the energy is completely lost and small interruptions may occur during normal operation due to power lines moved by the wind or other interruptions. brief. In addition, the process of repairing local power distribution failures commonly produces several brief energy restores, followed by a loss of energy, before the power is permanently restored. To prevent multiple calls from a plurality of meters, the interrupt timer 84 and the interrupt delay timer 86 may be configured to require that the power be removed for a predefined period of time and energy be applied to the meter 10 for a valid range of time before an interruption call is made. Specifically, if the values of both timers 84 and 85 are not within their respective valid ranges, a call will not be made to the central computer 56. With reference to Figure 7, when making a call 236 to the central computer 58, the microcomputer 52 initializes 250 the modem circuit 56. The initialization 250 includes configuring the circuit 56 to originate a call to the central computer 58, define a telephone number to call the central computer 58, and define the parameters related to the speed in baud, type of greeting and other communication parameters as known in the art. If the interrupt call parameter is in a true state indicating that a call is to be made during a power-interruption condition, the microcomputer 52 is delayed 252 for a defined period of time for the interrupt battery 36 to reach its load complete The call delay timer 88 is started 254 and the microcomputer 52 monitors the call delay timer 88 256 until the value of the call timer has an equal value, or valid range, defined during programming of the parameters 104. When the value of the call delay timer is within the valid range, the microcomputer 52 generates a status report 258 and a call 260 is made to the host computer 58 using the modem circuit 56. After the status report is generated 258 , the modem unit 56 supplies the status report to the telephone interface 64 and the telephone line 66 so that the status report is transferred to the central computer 58. If a call 262 is completed, the modem circuit 56 provides 264 a completed interrupt call signal to the microcomputer 52 and the power is removed 266 from the modem circuit 56. If the call is not completed, the timer call delay 88 restarts and starts 268. After the microcomputer 52 detects 270 that the call delay timer 88 is within a valid range, a second call 272 is made to the central computer 58. The second call can be made make the same telephone number as described above, or can be made to a second telephone number for the central computer 58. As described above, if the microcomputer 52 detects 274 that the second call is completed, the modem circuit 56 supplies 262 the interrupt call signal completed to the microcomputer 52 and the power is removed 264 from the modem circuit 56. If the call is not completed, the modem unit 50 stops and waits for the energy to be applied to the meter 10. It also they can include additional configurations, for example, a meter 10 can try any number of calls and any number of different numbers before stopping HE. In one modality and as shown in Figure 8, the generated status report 258 includes transferring the status information or data, from two tables stored in the memory 54. Specifically, the microcomputer 20 periodically runs a test or diagnostic routine to update 300 the status of the meter 10. The results of the diagnostic routine is transferred from the microcomputer 20 to the microcomputer 52 and 302 are stored in a meter status table in the memory 54. A state routine of the modem unit is executed by the microcomputer 52 to update 304 the state of the modem unit 50. The state of the resulting modem unit is stored in a modem state table in the memory 54. The generated status report 258 for transfer to the central computer 58 includes the content of the modem unit. the state table of the med idor and the state table of the modem unit. In another aspect of the present invention, to reduce the power consumption of the interruption battery 36, the interruption battery 36 only energizes the modem unit 50 during a power interruption. Specifically, in the case of a power interruption, before making a call to the central computer 58, the current microcomputer 52 hoists the state table of the modem and stores the updated state in the memory. Then, the non-required circuits are placed in a low energy reserve mode, until the interruption call is made. Once the modem unit 50 is connected to the central computer 58, the status report, including all the required status information, is passed to the central computer 58 by transferring the state table of the meter and the status table of the modem. As a result, the time required to transmit the information is reduced and this in turn reduces the power consumption of the interrogating battery 36. In another aspect of the present invention and in one embodiment, a statistical communication algorithm it is loaded into the central computer 58. Specifically, the algorithm is loaded and saved, in a memory of the central computer (not shown). Then, the algorithm is executed by a microcomputer, or microprocessor (not shown) in the central computer 58. The microcomputer of the central computer stores statistical data related to the information exchanged between the meter 10 and the central computer 58. The statistical data includes status information and error information. The status information is data concerning general byte counts and data packet counts. The error information is data that refers specifically to the number of errors, the number of bytes associated with an error, and the number of data packets associated with the errors. At the end of the exchange of information between the meter 10 and the central computer 58, the microcomputer of the central computer analyzes the statistical data. If certain portions of the data meet a previously established error criterion, then the data is stored in the central computer 58. The algorithm allows only data of interest to be saved thereby saving storage space and analysis time. In another aspect of the invention, to prevent all meters in an interruption area from calling central computer 58 at the same time, the valid range of call-back timer 88 may be unique for each meter 10. In one embodiment, a random delay is generated for each meter 10. The random delay is based on the generation of a random number in a specific range of an encrypted serial number seed, or initial value. For example, in one embodiment, the valid range of the call delay timer 84 is based on the unique serial number of the meter 10. Using the meter serial number, the microcomputer 52 generates a valid range for the interrupt timer 84 Specifically, the microcomputer 52 uses the encrypted serial number to generate the valid range for the interrupt timer 84. The nature of the encryption is such that two encrypted serial numbers generated from two consecutive meter serial numbers will generate very different valid ranges for the interrupt timer 84. As a result, the meters in the interruption area generate interrupt calls at different times. The valid range of each meter 10 can be programmed to include any valid range. Detect Scheduled Call and Scheduled Call Detect Scheduled Call 126 and Scheduled Call 130 refer to detecting whether the current time, as defined by the real-time clock 82, is within a valid range programmed or previously defined. If the value of the real-time clock 82 is within the valid range, the status report, as described above, is transferred to the central computer 58. Specifically, to transfer the status report, including billing information, to the computer central 58, the real-time clock 82 is monitored to determine whether the actual time matches a value stored in memory 54. The time value of the scheduled call can be set to specify a certain time, day, day of the week , day of the month, or a combination thereof. Upon detecting 126 that the real-time clock 88 is within the valid range, the modem unit 50 initiates a call to the central computer 58 as described above. Then, the status report, including the billing information, is transferred to the central computer 58. Calling the Central Computer and Answering Call Calling the central computer 130 and Answering Call 138 refer to the central computer 58 making a call to the meter 10. Specifically, and as shown in Figure 9, the central computer 58 initiates a call to the meter 10 using the telephone line 66. After detecting the call, the telephone interface provides an incoming call signal to the microcomputer 52. If a response parameter called 300 is detected in a true, or high state, the microcomputer 52 provides a call answering signal to the telephone interface 64 and the modem circuit 56 so that the call is answered 302. After to answer the call of the central computer 58, the modem circuit 56 performs the greeting 304 with the central computer 58 so that the d atos can be exchanged 306 between the central computer 58 and the meter 10.

The data is still exchanged 306 until the termination 308 of the exchange and at this time the modem circuit 56 and the central computer 58 hang 310 and the call is terminated. New Program and Update Program New program 142 and update program 146 refer to transmitting a new program to meter 10 of central computer 58. The new program is transmitted from central computer 58 to meter 10 so that the new program is saved in the modem unit 50. More specifically, the new program is transferred from the central computer 58 to the modem unit 50 to alter the operation of the meter 10. For example, the new program may alter the time of the next scheduled call, the valid ranges for the timer circuits 80 and the parameters of answering the call. The new program can also provide new phone numbers to call the computer centers! 58. In one embodiment, the new program is stored in memory 54 including two segments. Before receiving the new program from the central computer 58, the two segments are defined as an active segment containing the most recently programmed program or data, and an inactive segment containing the previously programmed data. When a new program is received, the new program data is saved in the inactive segment. If the programming session completes successfully, a complete programming signal from the false or initialized low state is changed to a true or high state. If it is detected that the complete programming signal is in a high state, the current active segment is changed to the inactive segment and the current inactive segment is changed to the active segment. If the programming is not completed and the complete programming signal does not go to a high state, a program call loss can be initiated in the host computer so that the programming can be completed. When the central computer 58 makes a call to the meter 10, the original designations of active and inactive segments will not change because the new program did not complete successfully. As a result, the modem unit 50 will always have a valid program, including operation parameters, so that the unit 50 can continue to function properly. Call Master / Subordinate and Update Master / Subordinate Call Master / Subordinate 158 and Update Master / Subordinate 162 refer to making a call to a group of at least two meters coupled to central computer 58 using a single telephone line 66. Specifically and as shown in Figure 10, meters 500A, 500B, 500C, 500D and 500E are coupled to the central computer 58 using a single telephone line 66. A meter, for example the 500A meter, is designated as a master meter, while the meters Remaining meters 500B, 500C, 500D and 500E are designated as subordinate meters. Each meter includes a unique identification number, stored for example in memory 54. The information, or data, is exchanged between central computer 58 and meters 500A, 500B, 500C, 500D and 500E using telephone line 66. With reference to Figure 11, when a telephone call is routed from central computer 58 to meters 500A, 500B, 500C, 500D and 500E using telephone line 66, meters 500A, 500B, 500C, 500D and 500E answer 602 the call . Specifically, after the master meter 500A greets 604 to the central computer 58, the meters 500A, 500B, 500C, 500D and 500E monitor 606 each, an incoming message, or data packet transferred from the central computer 58. The incoming message it includes an identification number corresponding to one of the meters 500A, 500B, 500C, 500D and 500E. The meters 500A, 500B, 500C, 500D and 500E each determine 608 if the transmitted identification number corresponds to the identification number stored in the memory 54 of each meter. If the identification number corresponds to the unique identification number stored in a meter, a transmission line of the modem unit 50 of the meter that matches the identification number is activated 610 and the transmission lines of the modem units of all the meters that do not match are deactivated 612. For example, if the number Identification number matches the meter identification number 500C, the transmission lines of the modem unit of meters 500A, 500C, 500D and 500E will be deactivated. After information is exchanged between the central computer 58 and the activated meter 500C, the meters 500A, 500C, 500D and 500E monitor the following incoming message 606. This routine continues until the central computer 58 ends the call and hangs up. In addition, the master / slave configuration allows the meters 500A, 500B, 500C, 500D and 500E to initiate a call to the central computer 58 as described above using the meter 10. Specifically, upon detecting a condition 106, one of the meters 500A, 500B, 500C, 500D and 500E initiates the call to the central computer 58. In one embodiment, the meters 500A, 500B, 500C, 500D and 500E are configured so that each meter has a unique valid range for circuit parameters of timer 80 and the valid time range of the program. For example, to prevent 500A, 500B, 500C, 500D and 500E meters from initiating calls without interrupting each other, meters 500A, 500B, 500C, 500D and 500E can be programmed to initiate calls only during a specific time window, for example. example, the meter 500A, 10:00 AM - 10:15 AM on 10/21/98, the meter 500B, 10:16 AM - 10:30 AM on 10/22/98, 500C, 10:45 AM -10: 59 AM on 10/22/98, 500D, 10:16 AM - 10:30 AM on 10/23/98 and 500E, 10:16 AM - 10:30 AM on 10/24/98. Each meter has a unique time window to originate the call to the central computer 58. Additionally, for events that are likely to occur simultaneously to all the meters in a group, for example, a power failure, the meters 500A, 500B, 500C, 500D and 500E may be configured so that only one meter generates a call to the central computer 58. Specifically, a call start parameter may be programmed in the modem unit 50 so that the microcomputer 52 can not initiate a call to the central computer 58. The modem unit described above exchanges information between the meter and the central computer after the occurrence of a condition in the meter. Then, the microcomputer of the modem unit evaluates the condition against the parameters stored in the memory 54. Using additional parameters, the microcomputer can then determine whether the information should be exchanged between the central computer and the meter. Also, the modem unit is configured to determine the appropriate time to exchange information between the central computer and the meter. It is considered that said modem unit reduces the number of annoying calls to the central computer. Additionally, the modem unit is configured to allow the meter to continue operating despite error conditions. Although the invention has been described in terms of several specific embodiments, those skilled in the art will recognize that the invention can be carried out with modifications within the spirit and scope of the claims.

Claims (74)

1. CLAIMS 1. A method of exchanging information between an electricity meter and a computer center! , the meter comprises a microcomputer and a modem coupled to the central computer, said method comprises the steps of: determining if there is a condition in the meter; and if the condition exists, then it will transmit a status report from the meter to the central computer after waiting for a previously defined period of time.
2. 2. A method according to claim 1, wherein determining whether a condition exists comprises the step of determining whether there exists at least one error, caution and diagnostic condition.
3. 3. A method according to claim 1, wherein transmitting the status report to the central computer after waiting for the previously defined time period comprises the steps of: initiating an event timer; determine if the event timer is within a valid range; if the event timer is within a valid range, then determine if the condition is within a valid range; and if the condition is within the valid range, then transmit the status report to the central computer.
4. 4. A method according to claim 3, wherein transmitting the status report to the central computer comprises the steps of: generating a status report; and transmit the status report of the meter to the central computer using the modem.
5. 5. A method according to claim 3, wherein determining whether the event timer is within the valid range comprises the step of comparing the event timer with a delay variable.
6. 6. A method according to claim 5, wherein comparing the event timer to the delay variable comprises the steps of: reading a meter serial number; and generate a unique delay variable based on the median serial number.
7. 7. A method according to claim 6, wherein reading the serial number of the meter comprises the steps of: reading a serial number stored in the meter; and encrypt the serial number.
8. 8. A method according to claim 3, wherein determining whether the event timer is within the valid range comprises the step of starting a delay timer.
9. 9. A method according to claim 8, further comprising the step of: determining whether the delay timer is within a valid range; and if the delay timer is not within the valid range, then re-start the delay timer. 1 0.
10. A method according to claim 9, wherein the modem of the meter comprises a non-volatile memory and wherein said method additionally comprises the step of whether the delay timer is within the valid range, then saving the value of the non-volatile memory delay timer. eleven .
11. A method according to claim 1, wherein the meter comprises a battery for energizing the meter during a power interruption and the modem comprises a non-volatile memory, and wherein transmitting the status report of the meter to the central computer comprises the steps: apply energy to the meter's modem using the battery; and transmit data from saved tables in the memory of the modem to the central computer using the modem.
12. 12. A method according to claim 1 1, wherein transmitting data from the tables comprises the steps of: reading a state of the microcomputer of the med idor; save the status of the meter in a meter status table in the modem memory; and save a modem status in a modem status table in the modem's memory.
13. 13. A method according to claim 12, wherein transmitting data from the memory tables of the modem further comprises the step of updating the tables.
14. 14. A method of exchanging information between a microcomputer of the electricity meter and a meter modem unit coupled to the meter's microcomputer, wherein the meter's microcomputer and the modem unit each comprise a password, said method comprising the step of: detecting if at least one of the meter password and the modem unit password is being changed; and if the passwords are being changed; then program the passwords on the meter's microcomputer and the modem unit.
15. A method according to claim 14, wherein detecting if at least one of the meter password and the password of the modem unit is being changed comprises the step of providing a deactivation signal of the meter microcomputer to the modem unit.
16. 16. A method according to claim 15, wherein detecting if at least one of the meter password and the password of the modem unit is being changed further comprises the step of: detecting whether the deactivation signal is providing the modem unit; and if the deactivation signal is detected in the modem unit, then deactivate the password of the modem unit.
17. 17. A method according to claim 1, wherein programming passwords in the microcomputer of the meter and the modem unit comprises the steps of: receiving the passwords of a central computer using the modem unit; save the password in the modem unit; and save the password in the meter's microcomputer.
18. 18. A method according to claim 1, wherein the modem unit comprises a non-volatile memory and wherein storing the password in the modem unit comprises the step of storing the password in the non-volatile memory.
19. 1 9. A method of exchanging information between a plurality of electricity meters and a central computer using a single telephone line, the meters comprising a master meter and at least one subordinate meter, each meter comprising a microcomputer, an identifier A single modem and a modem, said method comprises the steps of: activating the master modem to exchange information with the central computer; transmit information from the central computer to the meters; determine to which meter the information transmitted from the central computer is directed; If the transmitted information is directed to the master meter, then transmit information between the central computer and the master meter.
20. 20. A method according to claim 19, further comprising the step of: if the information transmitted from the central computer is not directed to the master meter, then it will determine which subordinate meter the information is directed to.
21. 21. A method according to claim 19, wherein the information transmitted from the central computer comprises identifier data and where to determine to which subordinate meter the information is directed comprises the steps of: determining whether the identifier data matches a unique identifier of subordinate meter; and if the identifier matches a unique identifier of the subordinate meter, then deactivate the master meter and activate the subordinate meter whose unique identifier matches the identifier data.
22. 22. A method according to claim 19, further comprising the step of transmitting a status report of the meter to the central computer.
23. 23. A method according to claim 22, wherein transmitting a status report comprises the steps of: determining whether a condition exists in at least one meter; If the condition exists, then initiate a call from the meter to the central computer using the meter's modem.
24. 24. A method according to claim 23, wherein initiating the call from the meter to the central computer comprises the step of transmitting the status report of the meter to the central computer at a certain time.
25. 25. A method according to claim 24, wherein each meter has a predetermined time to avoid interrupting another meter.
26. 26. A method according to claim 19, wherein activating the master meter for exchanging information with the central computer comprises the step of transmitting hello data between the master meter and the central computer.
27. 27. A method for programming an electricity meter comprising a microcomputer and a modem, said method comprises the steps of: programming the meter; determine if the meter programming is complete; and if the programming of the meter is complete, then it provides a programmed signal from the microcomputer to the modem.
28. 28. A method according to claim 27, wherein the programmed signal provided to the meter changes from a first state to a second state if the programming of the meter is complete.
29. 29. A method according to claim 28, wherein if the programmed signal remains in the first state, then the meter starts a pro- gram loss call to a central computer.
30. 30. A method according to claim 27, wherein the meter modem comprises a non-volatile memory having two segments and wherein programming the meter comprises the step of determining whether or not pro- gramming data were stored at the same time. last in the first segment or in the second segment of the memory.
31. 31 A method according to claim 30, wherein if the programming data was stored last in the first segment, said method comprises the step of setting a segment signal in a first state.
32. 32. A method according to claim 31, wherein if the programming data was stored last in the second segment, said method comprises the step of setting a segment signal in a second state.
33. 33. A method according to claim 32 further comprising the step of: determining if the segment signal is in a first state; and if the segment signal is in the first state, then execute a program stored in the first segment of the memory.
34. 34. A method according to claim 33, further comprising the step of whether the segment signal is in the second state, then executing a program stored in the second segment of the memory.
35. 35. A method of monitoring communication errors while exchanging information between an electronic electricity meter and a computor, this method comprises the steps of: transmitting data between the meter and the computer; analyze the data transmitted using the computer; determine if the transmitted data meet an established error criterion; and if the data meets the error criteria, then save the data to a file in the computer.
36. 36. A method according to claim 35, wherein analyzing the data comprises the step of tracking statistical communications data.
37. 37. A method according to claim 36, wherein the statistical data of com- munications comprises status information and error information.
38. 38. A modem unit for an electronic electricity meter to exchange data with a central computer, the meter comprises a microcomputer of the meter, said unit is coupled to the microcomputer of the meter and configured to: determine if there is a condition in the meter; and if the condition exists, then it will transmit a status report to the central computer after waiting for a previously defined period of time.
39. 39. A modem unit according to claim 38, wherein to determine if a condition exists, said unit is configured to determine if at least one error, caution and diagnostic condition exists.
40. 40. A modem unit according to claim 38, wherein said modem unit further comprises an event timer to measure time, and where to transmit the status report to the central computer after waiting the period of time previously defined, said unit is configured to: initiate said event timer; determine if the said event timer is within a valid range; if the mentioned event timer is within a valid range, then determine if the condition is within a valid range; and if the condition is within the valid range, then transmit the status report to the central computer.
41. 41. A modem unit according to claim 40, wherein for transmitting the status report to the central computer, said unit is configured to: generate the status report; and transmit the status report of the meter to the central computer.
42. 42. A modem unit according to claim 40, wherein said unit comprises a meter and wherein to determine if said event timer is within the valid range, said unit is configured to compare the event timer to a variable of delay stored in said memory.
43. 43. A modem unit according to claim 42, wherein in order to compare said event timer to said variable, said unit is configured to: read a meter serial number from the microcomputer of the meter; and generate said delay variable based on the serial number of the meter.
44. 44. A modem unit according to claim 43, wherein to read the serial number of the meter, said unit is configured to: read a serial number stored in the meter meter of the meter; and encrypt the serial number.
45. 45. A modem unit according to claim 40, wherein said unit comprises a delay timer to measure the time and wherein to determine if said event timer is within the valid range, said unit is configured for Start such a delay timer.
46. 46. A modem unit according to claim 45, wherein said unit is further configured to: determine if said delay timer is within a valid range; and if the delay timer is not within the valid range, then restart that delay timer.
47. 47. A modem unit according to claim 46, wherein said modem unit comprises a non-volatile memory and wherein if said delay timer is within the valid range, then save a value of such a timer. of delay in said non-volatile memory.
48. 48. A modem unit according to claim 38, wherein the additional memory comprises an energy interruption battery and such unit comprises a non-volatile memory, and wherein to transmit the status report of the meter to the central computer, said unit is configured to: receive energy from said battery; and transmit data from the tables stored in the aforementioned modem memory to the central computer.
49. 49. A modem unit according to claim 48, wherein for transmitting data from the memory tables said unit is further configured to: read a status of a microcomputer d icha of the meter; save the status of the meter in a meter status table in the mentioned memory of the modem unit; and saving a modem unit status in a modem state table in such a modem unit memory.
50. 50. A modem unit according to claim 48, wherein said modem unit is further configured to update said memory tables of the modem unit before the data is transmitted from such memory tables of the modem unit. modem.
51. 51. An electricity meter comprising a microcomputer and a modem unit, said modem unit and such microcomputer each have a password, said meter configured to: * determine if at least one of the aforementioned microcomputer password of the meter and such password of the modem unit is changed; and if it is changed; then program passwords in the mentioned microcomputer of the meter and such a modem unit.
52. 52. A meter according to claim 51, wherein in order to determine if at least one of said password of the meter microcomputer and said password of the modem unit is changed, said meter is configured to supply a signal to deactivate said one. microcomputer to such a modem unit.
53. 53. A meter according to claim 52, wherein to determine if at least one of said password of the microcomputer of the meter and said password of the modem unit is changed, said meter is additionally configured to: detect whether said signal to deactivate, a modem is being provided to the aforementioned; and if said signal to deactivate in such a modem unit, then deactivate such password of the modem unit.
54. 54. A meter according to claim 52, wherein for programming passwords in the meter's microcomputer and such a modem unit, said meter is configured to: receive a password from a central computer via such a modem unit; save such password in said modem unit; and save said password in such meter microcomputer.
55. 55. A meter according to claim 54, wherein said modem unit comprises a non-volatile memory and wherein to store said password in such a modem unit, said meter is configured to store said password in such non-volatile memory of the unit. of modem.
56. 56. A system for exchanging information with a central computer using a single telephone line, such system comprises a plurality of meters that each comprise a microcomputer, a unique identifier, and a modem board, such a system configured to: designate one of said meters as a master meter; designate the aforementioned meters as subordinate meters; activate such modem of the master meter; transmit information from the central computer to said meters; determine to which of these meters the information of the central computer is directed; If the transmitting information is directed to the master meter, then transmit information between the central computer and said master meter.
57. 57. A system according to claim 56 is additionally configured to determine to which of said subordinate meters the information is directed, if the information transmitted from the central computer is not directed to such a master meter.
58. 58. A system according to claim 56, wherein the information transmitted from the central computer comprises identifier data and in which to determine to which of said subordinate meters the information is directed, said system is configured to: determine if said data Identifier matches one of the unique identifiers of meters; and if said identifier matches a unique identifier of a subordinate meter, then deactivate said master meter and activate said subordinate meter whose unique identifier matches said identifier data.
59. 59. A system according to claim 56, further configured to transmit a status report of said meter to the central computer.
60. 60. A system according to claim 59 wherein for transmitting the status report, said system is configured to: determine if a condition exists in at least one meter; If the condition exists, then initiate a call from said meter to the central computer to transmit the status report.
61. 61 A system according to claim 60, wherein to initiate the call of said meter to the central computer, said system is configured to transmit said status report of said meter to the central computer at a predetermined time.
62. 62. A system according to claim 61, wherein each of said meters comprises a unique predetermined time to avoid interruption between each of said meters.
63. 63. A system according to claim 60, wherein to initiate a call from said meter to the central computer, said system is configured to initiate a call from said master meter to the central computer.
64. 64. A programmable electronic electricity meter that includes a microcomputer and a modem coupled to a central computer, said meter configured to: receive programming data from the central computer using said modem to program the meter; determine if such meter programming is complete; and if the programming of the meter is complete, then provide a programmed signal of such a modem to such a microcomputer.
65. 65. A meter according to claim 64, wherein said programmed signal of said modem changes from a first state to a second state if said programming of the meter is complete.
66. 66. A meter according to claim 64, wherein if the programmed signal remains in the first state, then said meter initiates a loss of program call to a central computer.
67. 67. A meter according to claim 61, wherein said meter modem comprises a non-volatile memory having at least two segments and wherein to program said meter, said meter is configured to determine if the programming data were saved. the latter in a first segment or a second segment of such a modem memory.
68. 68. A meter according to claim 67, wherein said meter is configured to set a segment signal to a first state if the programming data was stored last in said first segment.
69. 69. A meter according to claim 67, wherein said meter is configured to set a segment signal to a second state if the programming data was stored last in said second segment.
70. 70. A meter according to claim 69, further configured to: determine whether said segment signal is in said first state; and if the segment signal is in such a first state, then execute a stored program in the memory of said first segment.
71. 71 A meter according to claim 70, further configured to execute a program stored in said memory if said segment signal is in said second state.
72. 72. A system for monitoring communication errors while exchanging data between an electronic electricity meter and a computer, said system configured to: transmit data between the meter and the computer; analyze the data transmitted using the computer; determine if the transmitted data meet an established error criterion; and if the transmitted data meets the aforementioned error criteria, then save the data in a file on the computer.
73. 73. A system according to claim 72, wherein to analyze the transmitted data said system is configured to track statistical communications data.
74. 74. A system according to claim 73, wherein said communication statistics data comprise status information and error information.