Abstract:
A communications and control system for use with a utility meter includes a first wireless communications subsystem for exchanging messages with a central facility via a cellular communications network. The first wireless communications system is operable to send messages including meter data generated by the utility meter to the central facility and receive utility control messages from the central facility for controlling the provision of a utility monitored by the utility meter. A second wireless subsystem communicates within a wireless mesh network of compatible wireless subsystems operating in conjunction with a set of utility meters for exchanging the meter data with a selected compatible wireless subsystem within the mesh network.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/574,043, filed Jul. 27, 2011, U.S. Provisional Patent Application Ser. No. 61/627,415, filed Oct. 12, 2011, and U.S. patent application Ser. No. 13/507,758, entitled Systems and Methods for Wirelessly Communicating with Utility Meters and Utility Meters Using the Same, filed Jul. 26, 2012, which are incorporated herein by reference. 
    
    
     INCORPORATION BY REFERENCE OF COMPUTER PROGRAM LISTING APPENDIX 
     The present application incorporates by reference for all purposes the contents of the CDROM, labeled Copy 1 Disk, and an identical duplicate CDROM, labeled Copy 2 Disk, submitted with U.S. patent application Ser. No. 13/507,758 for all purposes. Each CDROM contains one (1) file entitled Code RDM and ERT.txt of 209 kilobytes. This file was created on Sep. 9, 2011 from firmware created Mar. 11, 2011. 
     FIELD OF INVENTION 
     The present invention relates in general to the distribution of utilities, and in particular, to wireless communications systems and methods particularly suitable for implementation in utility meters. 
     BACKGROUND OF INVENTION 
     With the advent of wireless communications, it is now possible for utility companies to continuously monitor and control services accessed by individual households and corporate users from a centralized facility. Besides significantly reducing the expense and difficulties associated with traditional in-person monitoring of utility usage, wireless utility monitoring and control systems allow for the implementation of additional capabilities that previously were too difficult or expensive to implement on an economically viable scale. 
     The distribution of electrical power is one particular area where wireless monitoring and control is particularly advantageous. Almost every home or business has an electrical meter that must be monitored, not only for billing generation, but also for the detection of faults and unauthorized consumption. Wireless systems allow for continuous and specific monitoring and control of individual customers within a very large distribution system without an undue amount of human intervention. Consumption is efficiently monitored and billed, faults quickly detected, and unauthorized users identified, all from a centralized location. In the case of unauthorized users, power can be terminated or reduced directly by wireless command. 
     In addition, wireless monitoring and control gives an electricity provider the ability to effectively control the load on its distribution grid during periods of high demand by managing the distribution of power to individual consumers or groups of consumers. Rolling “brown-outs” or “black-outs” can be pinpoint managed such that critical facilities (e.g., hospitals) are maintained while power to less critical facilities (e.g., individual households) can distributed on an equitable basis. At an even lower level of control, power to specific appliances, such as air conditioners, can be managed to reduce demand on the power grid. 
     The wireless monitoring and control systems currently available to utility companies are subject to some significant disadvantages. Among other things, most utility companies still maintain their own wireless communications networks for communicating with the meters. These systems are often limited in efficiency and cost effectiveness. Moreover, unauthorized users are often still able to circumvent the controls placed on their meters. 
     SUMMARY OF INVENTION 
     The principles of the present invention are embodied in systems and methods supporting two-way wireless communications between a central facility supporting an utility company and meters located at the customers of that company. Among other things, these principles allow wireless communications to be established between the central facility and the meters using a publically available cellular telephone network maintained by a wireless communications company. Different messaging protocols are supported, thereby allowing the most efficient and cost effective protocol to be used depending on the type and amount of data or commands being transferred. Additionally, a local wireless (mesh) network between a group of meters can be set-up and managed, wherein the central office communicates with a single node to transfer data and commands to and from the meters within the group. 
     According to one embodiment of the principles of the present invention, a communications and control system is disclosed for use with a utility meter, which includes a first wireless communications subsystem for exchanging messages with a central facility via a cellular communications network. The first wireless communications system is operable to send messages including meter data generated by the utility meter to the central facility and receive utility control messages from the central facility for controlling the provision of a utility monitored by the utility meter. A second wireless subsystem communicates within a wireless mesh network of compatible wireless subsystems operating in conjunction with a set of utility meters for exchanging the meter data with a selected compatible wireless subsystem within the mesh network. 
     According to particular embodiments of the present inventive principles, the first wireless communications system can exchange messaging with the central facility using either SMS or IP messaging protocols. Control messages are included for remotely connecting and disconnecting services associated with the utility meter and/or limit access to those services. In the case of an electrical meter, the central facility can transmit messages for connecting the metered user to electrical power, disconnecting that power, limiting the available current, or limiting access duration. 
     In further embodiments, the second wireless subsystem is operable collects meter data from at least one other compatible wireless subsystem for transmission to the central facility in a message via the first wireless communications subsystem and the cellular communications network. For an electrical meter embodiment, the meter data may include current, voltage, outage status, time of use, and tampering data. 
     Embodiments of the present principles advantageously allow an utility company to monitor and control individual meters within a system having a very large number of such meters. Consumption of a particular user can be monitored and efficiently billed. Faults, such as an excess current draw in the case of electricity, can be wirelessly identified and power to the given meter reduced or halted. Unauthorized usage, or usage exceeding a specified amount, can be similarly constrained or halted. Under excess demand conditions, rolling blackouts or brownouts can be managed on a pinpoint basis. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIG. 1A  is a diagram showing an integrated utility meter and multiple-mode wireless communications system embodying the principles of the present invention; 
         FIG. 1B  is a diagram of an utility meter collar system suitable for use in conjunction with a conventional utility meter and a multiple-mode wireless communications system according to the principles of the present invention; 
         FIG. 2  is a functional block diagram of a representative multiple-mode wireless communications system embodying the principles of the present invention and suitable for use in conjunction with the utility meters of  FIGS. 1A and 1B ; 
         FIGS. 3A-3D  are diagrams illustrating the printed circuit boards in one representative embodiment of the utility meter of  FIG. 1A ; 
         FIG. 4  is an electrical schematic diagram of a representative power filter according to the principles of the present invention and suitable for use in the power management circuitry shown in  FIG. 2 ; and 
         FIG. 5  is a conceptual chart illustrating a representative use of utility meters according to the principles of the present invention in a system environment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The principles of the present invention and their advantages are best understood by referring to the illustrated embodiment depicted in  FIGS. 1-5  of the drawings, in which like numbers designate like parts. 
       FIG. 1A  is a diagram of an exemplary integrated utility meter and multiple-mode wireless communications unit  100  embodying the principles of the present invention. As discussed in detail below, unit  100  allows a utility provider, or a third party contractor, to remotely monitor and control utility consumption by an end user through conventional electronic metrology circuitry and switches (i.e., switches  103  shown in  FIG. 2 ) provided in a conventional meter plug-in base (see  FIG. 3C , metrology circuit board  305  and meter base  308 ). In the illustrated embodiment, meter unit  100  implements an electric power meter, although the principles of the present invention are readily applicable to other types of utility meters, such as gas and water meters. 
     Among other things, meter unit  100  supports multiple modes of wireless communications between the utility provider (or its third party contractor) and the end user, including different wireless transmission protocols and different messaging options. Advantageously, meter unit  100  allows the utility provider to select the most efficient and/or cost effective communications system required to implement various metering functions (e.g., consumption, time of use, voltage, current, outage status, and tamper status), control functions (e.g., remote disconnect and remote connect), and local data processing. Meter Unit  100  is suited for use with households, apartment complexes, commercial establishments, and in general most private and public buildings. 
       FIG. 1B  is a diagram of a meter collar  101  embodying the principles of the present invention and designed to receive a standard electricity meter plug-in, which typically does not include metrology circuitry. In the collar embodiment, system  200  discussed below is primarily used for control of the user&#39;s consumption, such as remote connect and disconnect, and tamper detection. 
       FIG. 2  is a high level functional block diagram of communications and control system  200 . In the illustrated embodiment, communications and control system  200  connects to traditional 240V single-phase electric power lines (not shown) and includes conventional metering board in the base of unit  100  that provides metrology data such as voltage, current, consumption (in volt-amps per hour or kilowatts per hour), and emulated watt disk data. Consumption data is output from the metering board using a standard serial interface. Similar known metrology units are used to measure consumption and other usage parameters in embodiments of the present principles used in gas and water utility applications. A pair of conventional switches  103 , one for each phase of the input power, are provided in the unit base to connect and disconnect the end user to the power supply lines under the control of control system  200 . 
     In the illustrated embodiment, power from the conventional spades of the meter is tapped and passed through power management circuitry  201 . As discussed below in conjunction with  FIG. 4 , power management circuitry  201  includes filter and surge protection circuitry for providing power to the electronics of communications and control system  200 . The 240V two-phase power received from the meter spades is in the common mode and meter unit  100  floats, so a virtual ground for the electronics is created between unit  200  and the underlying metrology board. 
     The 240V two-phase filtered power output from power management circuitry  201  is provided to a power supply  202 , which is preferably a Mean Well NFM-10 series switching power supply outputting 3.3 V nominal for supplying the electronics of communications and control system  200 . Power supply  202  is preferably separated and isolated from the power supply for the metrology board. 
     Advantageously, power supply  202  has a relatively heavy transformer coil and does not employ output clamping or shunting. Consequently, the energy stored in the transformer core supports the power supply output with a current of about 2 amps for approximately 1 to 2 seconds after a power disruption, for example, from a failure of the grid or a disconnect of one or both of the input power lines. As discussed further below, this additional current output allows either the wireless modem or the radio frequency transmitter to issue a message indicating power disruption to the utility provider. As shown in  FIG. 3B , power supply  202  resides on a dedicated board  302  adjacent to the back face of primary board  301 . 
     A wireless modem  203  supports standard cellular communications with the utility provider across a commercially provided cellular communications network. Advantageously, the utility provider has a choice of communications carriers and is relieved of the responsibility of maintaining its own network. This is in contrast to typical utility monitoring systems, where the utility maintains its own network and therefore must address any subsequent communications network problems, in addition to its primary utility business. 
     In the illustrated embodiment, wireless modem  203  is a Wavecomm Q2687-RD quad band modem, which supports standard cellular (mobile) communications in either the GSM 850 MHz, E-GSM 900 MHz, DCS 1800 MHz, or PCS 1900 MHz bands. 
     Wireless modem  203  operates in conjunction with a system processor  204 , which is preferably a TI MSP 430 microcontroller. Exemplary code for the control of system processor  204  is found in the appendix (i.e., the “TI” portion of the code). Wireless modem  203  and system processor  204  preferably communicate via a standard serial interface, such as an SPI or I 2 C bus. 
     To support quad band communications, system  200  includes a quad band foil antenna  205  formed on one face of a summary circuit board  301 , shown in  FIG. 3A . Antenna  205  generally takes the shape of an inverted “f” and floats above the multiple-layer copper circuit board ground plane, in contrast with similar conventional antennas, which are grounded. Advantageously, the floating antenna  205  is less susceptible to noise caused by pulses of electromagnetic radiation in the vicinity of unit  100  (e.g., a lightening strike). Circuit board  301  contains multiple cavity style RF traps built into the geometry of the ground plane as well as discrete filters built with surface mount components to trap, shunt, and reduce harmonics of the 850 MHz and 1900 MHz cell phone bands. This combination yields efficiencies to cell band antennas in electric meter applications and overcomes the form factor limitations imposed by the meter dimensions. 
     Antenna  205  acts as a half-wavelength antenna for the GSM bands and as a quarter-wavelength antenna for the PCS and DCS bands. Alternate embodiments of circuit board antenna  205  contain series and parallel passive components that allow the antenna to have the characteristics of a folded dipole in the upper bands and a bent monopole antenna in the lower bands. 
     A conventional Subscriber Identity Module (SIM)  206  assigns meter  100  a cellular telephone number for communications. Advantageously, SIM  206  allows the utility to configure meter  100  to operate with any one of a number of different wireless communications carriers, as well as providing a unique identifier for system  200 . 
     Configuration code, as well as data from the metrology board, are stored in non-volatile external memory  207 , which preferably is Flash memory. Metrology data cycles in a first-in-first-out manner, with older data being overwritten by new data. As discussed further below, the utility company has a number of options with regards to the frequency at which metrology data is collected, the amount of data formatted into a message, and the frequency at which messages are pushed to or pulled from system  200 . Generally, the amount of data stored at any one time is a function of the amount and type of data taken with each measurement, the frequency at which measurements are taken, and the frequency at which data are returned. 
     Wireless modem  203  and system processor  204  allow the utility provider to communicate in different modes, depending on the amount of data being transferred per message and the frequency of the messages. In the illustrated embodiment, messages are sent using ASCII code as either a cellular connection using the Transmission Control Protocol (TCP)/Internet Protocol (IP) or as a Short Message Service (SMS) messages. For short messages (i.e., less than 160 characters), data are transferred using the SMS protocol, which typically has reduced expenses for the cellular services subscriber and decreases the power loading on system  200 . (A wireless connection using TCP/IP connections through wireless modem  203  can require up to two amps of current draw on power supply  202 ). On the other hand, a full wireless data connection, significantly more data can be transferred per session. Exemplary messages are discussed below. In the illustrated embodiment, although larger messages are exchanged using TCP/IP connections and a full wireless connection, this is not a requirement to practice the present principles. 
     Wireless modem  203  preferably enters a sleep mode between messages to save power and reduce noise within the remainder of the system. Wireless modem  203  can then receive wake-up command via an SMS message, after which communications may be established using TCP/IP messaging. Similarly, system processor  204  enters a sleep or low power mode when a sleep timer indicates a lack of activity for a programmed interval. System processor  204  will typically enter the sleep mode between wireless messages and between the receipt of metering data from the metrology board within the meter base. 
     A port  208 , which could be an IR port, a hard-wired serial port, or both, provides an alternate path for accessing metrology data stored in memory  207 . A hardwired port, when provided, also allows configuration changes or upgrades to system  200 , either in the shop or in the field. 
     Consumption data can be directly read from an LED display system including an LCD meter display  210 , and LCD driver  209 , and a temperature driver  211 . As shown in  FIG. 3A , temperature driver  211  measures the temperature directly at the back of LCD meter display  210 . LCD driver  209  then adjusts the contrast on LCD meter display  210  as a function of temperature by generally reducing the LCD drive voltage with increasing temperature, and vice versa. 
     In the preferred embodiment, a look up table is employed to determine the proper drive voltage for the temperature of the LCD so that the contrast remains consistent over temperature. In contrast to existing meter systems, system  200  does not use a separate temperature sensor in the immediate vicinity of the glass on the face of LCD display  210  to control the display. Instead, the temperature of the glass is calculated using temperature driver  211  and adjusting the contrast look up table value as a function of the amount of ac current passing through meter  100 . (The temperature of LCD display  210  will generally be a function of the current draw of the user, the heat generated by the electronics within unit  100  or  101 , and sunlight entering the unit enclosure.) This configuration eliminates the dedicated temperature sensor for LCD contrast, thus reducing parts and assembly costs. 
     System  200  implements a second wireless communications subsystem for establishing a mesh network between different users or between appliances within a single user node (e.g., a household or apartment). This mesh network subsystem includes an RF transceiver and processor mesh unit  213  and an RF antenna  212 . As shown in  FIG. 3C , mesh network subsystem  213  is disposed on a dedicated printed current board  303  disposed on the back face of primary circuit board  301 , generally parallel to wireless modem  203 . 
     In the preferred embodiment, mesh unit  211  includes a second TI MSP 430 microcontroller and a Sierra Wireless transceiver. Communications are implemented using a 915 MHz band frequency hopping spread spectrum protocol, which allows for emulation of the proprietary Itron ERT® SCM (“Electronic Receiver Transmitter”) transmission protocol. The data protocol used for mesh establishment and communications can also be a standard protocol, such as the ZigBee protocol. Exemplary code for the second TI MSP 430 microcontroller is also provided in the appendix (i.e., the “ERT” portion of the code). 
     One advantage of a mesh network connection is the ability to consolidate data from a set of meter units 100 , generate messages from the consolidated data, and then transmit those messages from a single master wireless modem  203 . The master wireless  203  may be in a selected one of set of meter units 100  or at a dedicated node. A meshed-network, for example, could be used in a subdivision or apartment complex where only a small number of cellular wireless modems  203  are required. 
     Hence, meshed network configuration minimizes the expenses and complexity of a system relying on multiple wireless modems  203 . In some embodiments of the present principles, wireless modem  203  may be eliminated from all but the meter units  100  acting as master nodes. In other embodiments, wireless modems  203  may be eliminated altogether, with the utility company downloading user data directly from the mesh network wirelessly, through a mesh unit  213  for example with a mobile, RF transceiver. 
     Additionally, the processor within mesh unit  213  can be programmed wirelessly from an external source. For example, mesh unit  213  can be programmed from a high power mode to a low power mode via an over-the-air firmware change in system processor  204  and/or the second processor within mesh unit  213 . Moreover, mesh unit  213  may be configured by direct connection or via over-the-air commands to set the “ERT” identification number, rate of transmission, number of transmissions, RF power out level (which allows for the emulation of high powered and low powered ERTs). Mesh unit  213  also can act as a stand-alone ERT reader, and can read nearby ERTs, either sorting by specific ID numbers or acting as a global collector and forwarding all ERT messages received to the network via wireless modem  203 . 
     Mesh unit  213  preferably can also communicate within a user network such as the Home Automation Network (HAN) to effectuate demand load control, time of use pricing, appliance interactivity, intelligent thermostat control, electric car charging, and in-home displays. In cases of heavy demand, an electric utility company, could, for example, reduce loading on the grid by reducing consumption by high demand appliances, such as air conditioners, water heaters, and swimming pool pumps, rather than by complete rolling blackouts or brownouts. 
     Antenna  212 , shown in  FIG. 3D , is preferably a folded whip antenna that floats above a ground plane of the (i.e., antenna  212  is not grounded like typical antennas). The floating configuration helps in protecting antenna  212  from surges and noise. 
     Utility WebConnect system  213  manages command messages being sent to meter unit  100  and the return of information from meter unit  100 . Through SMS messaging or cellular TCP/IP connections, a utility provider can implement a wide range of features. An exemplary set of commands that a utility can use are shown in Table 1. 
     Generally, a utility company can remotely connect, restrict a user&#39;s consumption or completely disconnect a user. A connection may be established, for example, for the new occupant of a home or apartment. A reduction in service or a complete disconnect can be voluntary or involuntary. A voluntary restriction on service might occur, for example, if a user is paying for service on a pay-as-you-go or pre-paid basis. 
     An involuntary restriction on service or complete disconnection might occur, for example, for failure to make payments, consumption of excess current, tampering with meter  100 , or on the detection of unauthorized use by the user. Advantageously, system  200  can generate reports on tampering or unauthorized use, as detected by the metrology unit for transmission to the utility provider. Tampering and unauthorized use can be detected, for example, by observing reverse current flow, back-feed, tilt and over-current conditions. 
     The message structure for wireless communications between system  200  and utility WebConnect system  214  is generally designed to: (1) Provide a high level of security; (2) reduce the risk of false activation of meter units  100  to an insignificant level; (3) provide a high level of corrupt message detection; and (4) provide flexible structure for future expansion. In the illustrated embodiment, messages include Command Messages sent from the utility provider to initiate an action and Unsolicited Messages sent from meter  100  either upon the occurrence of an event or periodically, without the need for polling by the utility provider master system. 
     The message structure, as well as message content, will vary from embodiment to embodiment of the principles of the present invention, as implemented by the particular programming for wireless modem  203 , system processor  204 , the processor of mesh unit  214 , and/or utility web connect system  214 . In the tables, “Pre-Pay” messages generally concern utility customers who have pre-paid for a particular amount of service, “Collar” messages pertaining only to the collar unit  101  shown in  FIG. 1B , “Meter” messages only for full meter units  100 , and “Both” for messages related to both full meter units  100  and collar units  101 . On Table 1, “meter unit” means the indicated unit  100 , collar unit  101 , or both. 
     To upgrade the firmware in meter  100 , utility WebConnect  214  sends an SMS message to meter  100  commanding meter  100  to retrieve a binary file from a back-end server on the network system and reprogram the firmware for either system processor  204  or the mesh unit  213  processor. More particularly, after receiving the command, meter  100  initiates an IP socket connection via wireless modem  203  to the back-end server requesting that the binary file be sent to it in 64 byte packets. Once all of the bytes have been received, error checked, and stored in the non-volatile memory  207 , the given microcontroller will initiate the re-write process. 
     A section of code (e.g., boot loader) will always reside in system processor  205  and/or the mesh unit  213  processor and manages the erasing of the rest of the corresponding program code blocks in assigned memory. Once system processor  204  or the mesh unit  213  processor has erased all of the code except for the boot loader portion, it will read the firmware image stored in non-volatile memory  207  and program it into the eased portions of the local memory. Meter unit  100  will then reboot and send a message that it has successfully completed a firmware upgrade. 
     Time of use (TOU) information can be requested by WebConnect system  213  by using either an SMS message or a wireless connection and the IP protocol. (TOU information is particularly useful for pre-paid user accounts.) Generally, the two methods are mutually exclusive, such that a request via SMS must generate an SMS response and an IP request must generate an IP response. 
     In the illustrated embodiment, the TOU option must be enabled by the command shown in Table 1, preferably by an SMS message. After receiving the command, meter unit  100  responds with an acknowledgement that the command was received and processed. If no acknowledgement was received then the command times out and must be resent. TOU use is similarly disabled by an SMS command. 
     If TOU is enabled, meter  100  responds back with the packet number requested. A typical response message will include the meter reading and the date and time of that meter reading. The response is repeated as necessary to give meter readings spaced by time and/or date intervals set during enablement of the TOU feature. The first packet (e.g. Packet 000) is preferably the most current meter data. 
     In the illustrated embodiment, memory  207  generally has the capacity to store up several days, or even a month or more, of information, such that the utility company can download a sequence of meter readings taken over a defined period of time. For example, meter readings taken at one hour intervals spaced over a single day could be sent to the utility provider every midnight, every other day, once a week, and so on. 
     When the utility provider only requires small amounts of data, for example periodic meter readings of single data points, SMS messaging is the preferred vehicle, given the reduced expenses and overhead burden on system  200 . In the case of SMS, messages are preferably encrypted at WebConnect system  215  and system  200  using an encryption method of the utility provider&#39;s choice. 
     When larger amounts of data are being transferred, for example meter readings for several days, the IP protocol across a wireless cellular connection is preferable. In this case, most wireless carriers encrypt data using industry standard encryption routines. 
     WebConnect system  214 , along with the messages and commands of Table 1, implement a number of additional important functions. For example, zeroing meter  100  or setting current limits on the user. Records onboard meter  100  also indicate the date and time of a power outage and the date and time when power was restored, and are retrievable on command by WebConnect system  214 . 
     Meter  100  also logs instances of tampering (e.g., movement of meter  100 ) and unauthorized use. These logs can be retrieved from by WebConnect system  214  by a Poll command and the Close command used, as deemed appropriate, to disconnect the user. 
     As discussed above, power supply  202  provides about one to two seconds of additional power at approximately two (2) amps after a power outage. The unsolicited Grid Power Failure Message, which can be sent via either an SMS or IP protocol message, provides a “last gasp” indication to WebConnect system  214  that a power outage has occurred in the power grid encompassing the area in which meter  100  resides. 
     Meter Unit  100  is normally sealed by the utility provider to prevent or detect tampering. Some embodiments of the principles of the present invention include an external button, which is enabled by remote command by the utility provider, allowing an end user to connect and disconnect service. Additional embodiments of meter  100  include an internal button, such as button  307  shown in  FIG. 3A , which is only accessible by personnel authorized to break the seal on meter  100  and is only operable when activated by the proper wireless command to system processor  204 . 
     The sealing of meter unit  100 , along with the ability to remotely detect tampering, provides an additional advantage, namely, that the proprietary hardware, software, and hardware within system  200  is also protected against unauthorized access. The ability to detect tampering both remotely and by observation of the seal is particularly important given that wireless modem  203  and SIM  206  provide access to a wireless network, which could allow an unauthorized party to appropriate system  200  as a communications device and/or hack into the utility company&#39;s system. The ability to detect tampering this is also important to ensure unauthorized access and assumption of control over meter  100  through mesh unit  213 , as well as unauthorized access to electrical power. 
     Different meter bases may be used in integrated meter unit  100 , as well as with collar  101 . Differing bases may also used different types of switches  103 , which generally are power relays rated nominally at 240 VAC and 200 amps on the switched power lines. Some relays may be either continuous duty or latching DC controlled relays. Other relays may be continuous duty or latching AC controlled relays. Advantageously, system  200  can be programmed to provide the proper voltages for the type of relays used in the selected base. 
     In the case of DC relays, programmable drive circuitry within power management block  201  is programmed to the required nominal relay control voltages and then monitors and maintains those voltages within tolerances. For AC controlled relays, the drive circuitry is programmable for control voltage, as well as duty cycle and AC phase angle switch on and off times. 
       FIG. 4  is an electrical schematic diagram of power filter  400  within power management unit  202  of  FIG. 2 . Power for system  200  is tapped from the conventional spade connectors  401   a  and  401   b  on the unit base  308  and receive 240 volt single-phase ac power. Filter  400  is disposed on filter board  305 , which, as shown in  FIG. 3C , extends general orthogonal to primary circuit board  301  and metrology circuitry board  305  on unit base  308 . 
     A gas discharge tube  402 , preferably with a nominal breakdown voltage of 600 volts, bridges the filter input and controls voltage spikes and similar overvoltage conditions. The power inputs then pass through a common mode choke  403 , which is rated, for example at 6.8 mH, and 1.7 amps. The two lines line on the output side of choke  403  pass through power resistors  404   a  and  404   b  having an exemplary resistance of 580 ohms and rated at 5 watts. 
     Across the outputs of resistors  404   a - 404   b  are a second gas discharge tube  405  and a metal oxide varistor (MOV)  406 , which provide additional protection against voltage spikes and other overvoltage events. Second gas discharge tube  405  has an exemplary breakdown voltage of 600 volts. MOV  406  is, for example, a Littlefuse V275LA40AP MOV. 
     A filtering capacitor  407  (e.g., 0.1 uF, 100 ohms, 600 watts) is provided between the AC lines, followed by a second set of power resistors  408   a - 408   b , also having an exemplary resistance of 580 ohms and rated at 5 watts. Resistors  408   a - 408   b  are followed by filtering capacitors  409  (e.g., 0.0018 uF, 2.5 kV) and  410  (e.g., 0.1 uF, 400 V). A transient voltage suppression diode  411  (e.g., 320 V) clamps the output of filter  400  in the event of voltage spikes. 
     In addition to protection against current surges and high voltage transients, filter  400  also generally acts as a hybrid Pi-Butterworth filter for removing noise on the input AC power lines. 
     Common mode choke  403  generally blocks high frequency common mode noise caused, for example, by a lighting strike in the vicinity of meter  100  or a similar surge event that injects noise onto the ac power lines. Noise and voltage spikes that pass through with the differential power signal are shunted by gas discharge tube  405 , MOV  406 , and/or diode  411 . According to the principles of the present invention, filter  400  is disposed on a filter board  304  generally orthogonal to the main board  301  of system  200  and the metrology printed circuit board  305 , as shown in  FIG. 3C . Common mode choke  403  is disposed on filter board  302  such that its longitudinal axis is parallel to the ground plane of the underlying metrology board  305 . 
     In this configuration, the magnetic (B) field generated by common mode choke  403  is generally parallel to the plane in metrology base printed circuit board  305 . In response to high current, high frequency, common mode transients on the AC input power lines, an image current to the common mode high frequency current is established in the metrology board ground plane. The magnetic field of this image current will tend to cancel-out at least some of magnetic field of the transient current, assisting in dissipating the energy of the current transient. Additionally, capacitive coupling between choke  403  and the metrology board ground plane will couple some high frequency energy to ground. 
       FIG. 5  is a flow chart of a direct load control (DLC) procedure  500  embodying the principles of the present invention. Procedure  500  is preferably implemented using meter unit  100  or collar  101  and WebConnect system  214 , although other types of metering units and control systems can be used in alternate embodiments. Furthermore, while procedure  500  is discussed using electric power consumption as an example, it is equally applicable to controlling the consumption of other utility services, such as water and gas. 
     As shown in Table 1, meter unit  100  and collars  100  can cycle electrical power to customers in selected increments by opening and closing switches  103  (e.g., 30 minutes on and 30 minutes off) in response to wireless commands. Meter  100  and collar  101  can also be used to wireless monitor current consumption and determine when a customer&#39;s usage exceeds a certain level. Using these features, a utility company can reward customers for participation in efforts to reduce power consumption during high demand events or emergencies. 
     For example, a customer can volunteer for a hard disconnect (e.g., whole house disconnect) during a high demand period or emergency (“demand event”), wherein meters  100  and/or collars  101  are used by the utility provider to cycle power to volunteering customers to reduce loading on the grid. Those customers who accept a hard disconnect under demand events are rewarded with a reduction in pricing, credit, or other compensation. 
     Alternatively, customers can volunteer for a virtual disconnect during a demand event, wherein the customers are given consumption parameters (e.g., a reduced current level, time duration at the reduced current level, and time of day of the reduction) via email or text messaging and then monitored for compliance with those parameters. In this case, the means of power reduction (e.g., shutting off air conditioning, water heaters, pool pumps, and so on) is left to the customer&#39;s discretion. Those customers who successfully reduce consumption throughout the event are rewarded, while those who drop out of the event (i.e., fail to reach or maintain the consumption parameters) are not rewarded. (The utility company can similarly control usage through mesh unit  213  and a HAN of given users.) 
     In procedure  500 , the utility company monitors its grid (Block  501 ) and detects a demand event (Block  501 ). At Block  502 , the utility provider polls the customers for real time consumption data (e.g., current consumption) to determine the extent of the required demand reduction. From this information, the utility company prices the event (Block  503 ) to determine the amount of reduction required and the amount of rewards needed to achieve that reduction. At Block  504 , the utility company determines the consumer parameters required to achieve the necessary reduction and sends those parameters (e.g., a reduced current level, time duration at the reduced current level, and time of day of the reduction), along with the prospective reward, to participating customers at Block  505 . 
     The customer is given options, at Block  506 , for load reduction based on the received parameters and prospective reward. For example, customer accepting a greater reduction in current over a longer period of time, which encompasses typically high demand time of day, will receive a greater reward than a customer accepting a smaller reduction in current and/or a short duration of reduced current consumption. The customer can also select between a hard disconnect or virtual disconnect. The customer preferably responds to the utility provider within five (5) minutes (Block  507 ). (Customers not responding, or not responding in timely fashion, may not be accepted to participate and receive the incentive.) 
     At Block  508 , the utility provider validates the response from the given customer and awards the event to that customer at Block  509 . In other words, the utility provider may not require a reduction from all customers within the program to achieve the desired loading on the grid and therefore need only accept a certain number to receive prospective rewards. 
     Customer usage, particularly those accepting virtual disconnection, are monitored during the demand event at Block  510 . If, at Block  511 , the event is considered to be a success for a customer (i.e., the customer has met the reduction parameters), the customer is rewarded with cash or credit at Block  512 . 
     Although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed might be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
     It is therefore contemplated that the claims will cover any such modifications or embodiments that fall within the true scope of the invention. 
     
       
         
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Meter 
                 Message 
                   
               
               
                 Message 
                 Type 
                 Type 
                 Function 
               
               
                   
               
             
             
               
                 OPEN 
                 Both 
                 Command 
                 Unconditionally opens the AC power 
               
               
                   
                   
                   
                 switches. 
               
               
                 CLOSE 
                 Both 
                 Command 
                 Closes the AC power switches. 
               
               
                 ARM 
                 Both 
                 Command 
                 Sets meter into home-owner contact mode 
               
               
                   
                   
                   
                 allowing contact closure through a manual 
               
               
                   
                   
                   
                 button press. 
               
               
                   
                   
                   
                 Illuminates the LED in the home-owner 
               
               
                   
                   
                   
                 button and is only set when meter unit is in 
               
               
                   
                   
                   
                 OPEN mode. Meter waits for new command 
               
               
                   
                   
                   
                 or for button press. 
               
               
                 CYCLE 
                 Collar 
                 Command 
                 Sets meter unit into a cycle mode, for 
               
               
                   
                   
                   
                 example, 30 minutes off, 30 minutes on. 
               
               
                   
                   
                   
                 Meter cycles through OPEN and CLOSE 
               
               
                   
                   
                   
                 states staying in the OPEN state for 30 
               
               
                   
                   
                   
                 minutes, and then swapping to the CLOSE 
               
               
                   
                   
                   
                 state for 30 minutes. A new OPEN or 
               
               
                   
                   
                   
                 CLOSE command ends cycle mode. 
               
               
                   
                   
                   
                 An over current condition will suspend the 
               
               
                   
                   
                   
                 cycle mode, which is re-started if the meter 
               
               
                   
                   
                   
                 unit goes in to the ARM mode from the over- 
               
               
                   
                   
                   
                 current condition whilst in the cycle mode. 
               
               
                 CYCLE 
                 Meter  
                 Command 
                 Sets meter into a cycle mode for mmmm 
               
               
                 mmmm, pppp 
                   
                   
                 seconds, off for pppp seconds. Meter cycles 
               
               
                   
                   
                   
                 through OPEN and CLOSE states staying in 
               
               
                   
                   
                   
                 the OPEN state for mmmm seconds, and 
               
               
                   
                   
                   
                 then swapping to the CLOSE state for pppp 
               
               
                   
                   
                   
                 seconds. A new OPEN or CLOSE command 
               
               
                   
                   
                   
                 ends cycle mode. 
               
               
                   
                   
                   
                 An over current condition will suspend the 
               
               
                   
                   
                   
                 cycle mode, which is re-started if the meter 
               
               
                   
                   
                   
                 goes in to the ARM mode from the over- 
               
               
                   
                   
                   
                 current condition whilst in the cycle mode. 
               
               
                 SET_CURRENT  
                 Meter  
                 Command 
                 Sets current limit in range in range 0 to 50A 
               
               
                 aaab 
                   
                   
                 (0 = no limit). Sets a new current limit to aaa 
               
               
                   
                   
                   
                 amps, where b sets options: 0 = Arm and 1 = 
               
               
                   
                   
                   
                 Timed five minutes. Meter unit will look at 
               
               
                   
                   
                   
                 an average current draw over a 10 second 
               
               
                   
                   
                   
                 window. 
               
               
                 POLL 
                 BOTH 
                 Command 
                 Commands meter to respond with status 
               
               
                   
                   
                   
                 update. Meter unit responds with current 
               
               
                   
                   
                   
                 status including: meter read, current reading, 
               
               
                   
                   
                   
                 output status, contactor (switch) status, input 
               
               
                   
                   
                   
                 status, error count, voltage, and signal level. 
               
               
                   
                   
                   
                 Error count is incremented every time the 
               
               
                   
                   
                   
                 host meter receives a message it cannot 
               
               
                   
                   
                   
                 understand and discards (e.g., either random 
               
               
                   
                   
                   
                 text or a message with corrupted 
               
               
                   
                   
                   
                 characters). 
               
               
                 POWER_UP 
                 Both 
                 Unsolicited 
                 When power is applied to the meter unit, it 
               
               
                   
                   
                   
                 responds by sending the unsolicited power 
               
               
                   
                   
                   
                 up message. 
               
               
                 GRID POWER 
                 Both 
                 Unsolicited 
                 When power is lost to a meter unit, an 
               
               
                 FAILURE 
                   
                   
                 unsolicited message is generated with a ST 
               
               
                   
                   
                   
                 code of (30). 
               
               
                 SET_VOLTAGE 
                 Meter 
                 Command 
                 Sets a new voltage limit to vvv volts (in 
               
               
                 vvv 
                   
                   
                 range 0 to 360, with 0 = no limit. This limit 
               
               
                   
                   
                   
                 can be set for High or Low triggering using 
               
               
                   
                   
                   
                 OpCode VA. Meter will look at an average 
               
               
                   
                   
                   
                 voltage draw over a 30 second window 
               
               
                 TAMPER 
                 Meter 
                 Command 
                 When the meter is turned upside down or 
               
               
                 DETECT 
                   
                   
                 moved it increments bits that can be read via 
               
               
                   
                   
                   
                 the POLL command. 
               
               
                 TIME OF USE 
                 Pre- 
                 Command 
                 Request the time of use via SMS for a meter 
               
               
                 (TOU) 
                 Pay 
                   
                 in 15 min increments, where ppp is the index 
               
               
                 ppp 
                   
                   
                 or packet number to request from the meter. 
               
               
                   
                   
                   
                 If meter does not have TOU enabled then it 
               
               
                   
                   
                   
                 will respond with NAK on any request for 
               
               
                   
                   
                   
                 packet index. 
               
               
                 Tlsss,eee, 
                 Pre- 
                 Command 
                 Request the time of use via IP for a meter in 
               
               
                 APN,IP,PORT 
                 Pay 
                   
                 15 min increments, where: sss is the start 
               
               
                   
                   
                   
                 index or packet number to request from the 
               
               
                   
                   
                   
                 meter; and, eee is the end index or packet 
               
               
                   
                   
                   
                 number to request from the meter. APN is 
               
               
                   
                   
                   
                 the APN Domain name to use when 
               
               
                   
                   
                   
                 connecting via IP messaging. IP is the IP 
               
               
                   
                   
                   
                 address of the Server to Connect to. PORT 
               
               
                   
                   
                   
                 is the port number to connect on. Response 
               
               
                   
                   
                   
                 to above will be ACK. If meter does not 
               
               
                   
                   
                   
                 have TOU enabled then it will respond with 
               
               
                   
                   
                   
                 NAK on any request for packet index. 
               
               
                 TYssss 
                 Pre- 
                   
                 Enables the time of use feature in the meter 
               
               
                   
                 Pay 
                   
                 unit, where ssss is the interval in seconds for 
               
               
                   
                   
                   
                 time of use collection in meter. 
               
               
                   
                   
                   
                 Preset values would be: 
               
               
                   
                   
                   
                 Five Seconds : 0005 
               
               
                   
                   
                   
                 Ten Seconds : 0010 
               
               
                   
                   
                   
                 30 Seconds : 0030 
               
               
                   
                   
                   
                 1 Minute : 0060 
               
               
                   
                   
                   
                 5 Minute : 0300 
               
               
                   
                   
                   
                 6 Minute : 0360 
               
               
                   
                   
                   
                 12 Minute : 0720 
               
               
                   
                   
                   
                 15 Minute : 0900 * Default 
               
               
                   
                   
                   
                 20 Minute : 1200 
               
               
                   
                   
                   
                 30 Minute : 1800 
               
               
                   
                   
                   
                 60 Minute : 3600 
               
               
                   
                   
                   
                 Response to above will be ACK 
               
               
                 TM 
                 Pre- 
                 Command 
                 Disable the Time of use feature in the meter 
               
               
                   
                 Pay 
                   
                 unit. Response to above will be ACK 
               
               
                 Software Reset 
                 Meter  
                 Command 
                 Software reset of system 200 module, 
               
               
                   
                   
                   
                 Where mode is: 
               
               
                   
                   
                   
                 0: Reboot immediately 
               
               
                   
                   
                   
                 1: Enable/Disable Automatic Reboot 
               
               
                   
                   
                   
                 Reboot freq is the reboot frequency for 
               
               
                   
                   
                   
                 automatic reboot (in hours). 
               
               
                 Query Meter 
                 Meter  
                 Command 
                 Used to retrieve the current meter factor for 
               
               
                 Factor 
                   
                   
                 meters being displayed and read. 
               
               
                 Mesh 
                 Meter  
                 Command 
                 Configuration for mesh meter 213. 
               
               
                 Configuration 
                   
                   
                   
               
               
                 Query Mesh 
                 Meter  
                 Command 
                 Returns mesh unit 213 ID. 
               
               
                 Configuration 
                   
                   
                   
               
               
                 Reset Meter 
                 Meter  
                 Command 
                 Reset meter unit reading. 
               
               
                 Firmware 
                 Meter  
                 Command/ 
                 Request a firmware update from the server. 
               
               
                 Update 
                   
                 Unsolicited 
                   
               
               
                 General Packet 
                 Meter  
                 Command/ 
                 General packet sent from meter to server 
               
               
                   
                   
                 Unsolicited 
                 using IP protocol. Server responds with 
               
               
                   
                   
                   
                 packet number requested. 
               
               
                 Get Version 
                 Both 
                 Command/ 
                 Request the current firmware/ hardware 
               
               
                   
                   
                 Unsolicited 
                 versions. 
               
               
                 Status 
                 Meter/ 
                   
                 STATUS = unsolicited message (00000 
               
               
                   
                 Pre- 
                   
                 message ID) sent to database to indicate 
               
               
                   
                 Pay 
                   
                 specific change of state in meter: 
               
               
                   
                   
                   
                 10 Account Balance Reached 
               
               
                   
                   
                   
                 11 Set Level 1 Credit 
               
               
                   
                   
                   
                 reached(Pre-Pay) 
               
               
                   
                   
                   
                 12 Set Level 2 Credit 
               
               
                   
                   
                   
                 reached(Pre-Pay) 
               
               
                   
                   
                   
                 13 Set Level 3 Credit 
               
               
                   
                   
                   
                 reached(Pre-Pay) 
               
               
                   
                   
                   
                 14 Set Level 4 Credit 
               
               
                   
                   
                   
                 reached(Pre-Pay) 
               
               
                   
                   
                   
                 15 Set Level 5 Credit 
               
               
                   
                   
                   
                 reached(Pre-Pay) 
               
               
                   
                   
                   
                 16 Set Level 6 Credit 
               
               
                   
                   
                   
                 reached(Pre-Pay) 
               
               
                   
                   
                   
                 17 Set Level 7 Credit 
               
               
                   
                   
                   
                 reached(Pre-Pay) 
               
               
                   
                   
                   
                 18 Set Level 8 Credit 
               
               
                   
                   
                   
                 reached(Pre-Pay) 
               
               
                   
                   
                   
                 19 Set Level 9 Credit 
               
               
                   
                   
                   
                 reached(Pre-Pay) 
               
               
                   
                   
                   
                 20 Contactor (switches) closed by 
               
               
                   
                   
                   
                 home owner /ARM button being 
               
               
                   
                   
                   
                 pressed 
               
               
                   
                   
                   
                 21 Meter tried to CLOSE contactor 
               
               
                   
                   
                   
                 (switches) and detected a backfeed 
               
               
                   
                   
                   
                 condition 
               
               
                   
                   
                   
                 22 Meter tried to CLOSE contactor 
               
               
                   
                   
                   
                 and failed 
               
               
                   
                   
                   
                 23 Meter tried to OPEN contactor 
               
               
                   
                   
                   
                 and failed 
               
               
                   
                   
                   
                 30 Grid Power Off Detected 
               
               
                   
                   
                   
                 40 Current Limit Exceeded. 
               
               
                   
                   
                   
                 Waiting for Timeout to Connect. 
               
               
                   
                   
                   
                 41 Current Limit Exceeded. 
               
               
                   
                   
                   
                 Waiting for home owner button to be 
               
               
                   
                   
                   
                 pressed. 
               
               
                   
                   
                   
                 42 Current Limit Exceeded. 
               
               
                   
                   
                   
                 Maximum number of retries 
               
               
                   
                   
                   
                 reach. Manual Connect 
               
               
                   
                   
                   
                 required. 
               
               
                   
                   
                   
                 43 Current Limit Re-Connected 
               
               
                   
                   
                   
                 after Timeout. 
               
               
                   
                   
                   
                 60 Grid Power Off Detected with 
               
               
                   
                   
                   
                 Tamper 
               
               
                   
                   
                   
                 70 Voltage Limit detected 
               
               
                   
                   
                   
                 71 Voltage Limit restored 
               
               
                   
                   
                   
                 80 Meter Reset Button Pressed. 
               
               
                   
                   
                   
                 Resetting Kw Hours to Zero 
               
               
                   
                   
                   
                 90 Rate Exhausted