Abstract:
A premise system that is reliable, easy to install and easy to maintain, that provides data to a computing platform detailing the energy usage of the consumer, allowing the utility company to dynamically adjust rates and output levels so as to increase cost savings. An energy management system according to the invention is designed as a network of devices installed in the home or small office to efficiently make use of heating, ventilation, and air-conditioning (“HVAC”) units and other appliances. Module devices installed on the network may communicate and transmit energy usage data to a central server, for example, located at the utility company. The utility company monitors the usage data as the data is periodically received and is able to generate messages that initiate energy saving programs specific to each premise.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims the benefit under 35 U.S.C. §119(e) of co-pending and commonly-assigned U.S. Provisional application serial No. 60/391,453 entitled “Premise Equipment Control System and Method” filed on Jun. 24, 2002, by, which application is incorporated by reference herein. 
     
    
     
       FIELD OF INVENTION  
         [0002]    The present invention relates to an energy management system and particularly a cost-efficient, high functionality energy management system.  
         BACKGROUND OF THE INVENTION  
         [0003]    Nearly all homes are connected to a series of energy networks. Each home contains a utility meter, usually on the exterior of the house from which all energy used is recorded. Newer utility meters utilize Automated Meter Reading (“AMR”) technology to facilitate the reporting of energy usage data. These AMR-enabled meters broadcast data on a short range basis to a receiver carried by the utility technician. This allows the technician to gather usage data simply by being in close proximity to the AMR-enabled meters. Utility company employees record a periodic reading from these meters to determine the amount of use and the cost of the utility to be billed to the consumer. Energy management systems have become increasingly popular in the last several years due to cost concerns and environmental concerns. Before these management systems were implemented, a climate control system was governed by a temperature setting. If a threshold temperature was met or crossed by the ambient temperature, the climate-control system would initiate operation until the temperature settled back to the threshold. In a heat-providing system, if the temperature fell below the threshold setting, the heater would initiate and continue operating until the ambient temperature increased back to the set temperature. In an air conditioning system, if the temperature grew above the set threshold, the air conditioner would initiate and begin cooling the air space until the threshold temperature was met. A combination of heating and air-conditioning systems is also readily available. This type of system creates equilibrum by maintaining the temperature at the desired level at all times.  
           [0004]    A home, however, may not need to be at the equilibrium temperature at all times. It is costly to heat or to cool a home at times when no one is present to benefit from the climate-control system. Not only does this increase costs for the consumer, but also for the utility companies. Providing unnecessary electricity and gas to homes and buildings creates an enormous strain on the utility companies and increases operating costs. An excess of wasted energy and excess strain on the utility system can lead to brownouts and create energy crises for everyone on the energy network.  
           [0005]    Energy management systems may include a programmable thermostat that initiates signals to a heater or air conditioner at pre-determined intervals. Examples include timers that define time periods throughout the day and night when the climate-control system should be operative and maintain the set temperature. More sophisticated thermostats may include programmable parameters, such as day of the week, time, fan on/off, etc., that create multiple comfort periods based on the value of the parameters.  
           [0006]    While these types of energy management systems have become progressively more sophisticated there still remains a gap between the utility company and the consumer preventing substantial cost savings for both parties.  
           [0007]    Certain systems have developed whereby a home-network or premise system can be used to monitor and control climate-control devices as well as other appliances throughout the home. Microprocessors, with wired connections to the appliances and to the utility meters, interface with the appliance and serve as a management device for controlling and monitoring the appliance. A central command and control center for climate-control devices in a user-friendly setting, such as a personal computer (“PC”), facilitates the consumer&#39;s control and use over these devices, however there is no link to the utility provider itself. The utility provider must still provide the same power at constant rates and constant levels. The cost savings, if any, are only present on the consumer end of the transaction.  
           [0008]    Known energy management systems are either very expensive and require significant rewiring of the house or are less-expensive and have a poor-reliability factor. The less-expensive systems use pre-existing wiring, however a bridge or amplifier is needed to increase signal strength. Previous systems do not provide the capability of a uniformly applicable system that requires little configuration based on the installation environment. Significant configuration differences exist in previous systems between a design for a small house compared to that of a large house or office building. Differences in PC hardware, operating systems, and related software applications can create further difficulties in installation and maintenance. The combination of varied installation environments as well as differences in control software environments can contribute to poor reliability.  
           [0009]    Other systems have the functionality to communicate with utility companies, such as a system designed by Carrier Corporation, in partnership with Silicon Energy Corporation. The end premise system includes a thermostat and controller device. The thermostat communicates with the controller through a RF or wired connection. The utility company, through computing servers communicate to the thermostat through a bidirectional paging network. Installation of this type of system requires that the controller device be placed to optimize paging reception and transmission, often requiring installation in an attic. Application of this system is limited to premises located in strong paging network areas. A utility company, using a web-based application sends signals to the connected thermostats and changes the thermostat settings. These changes may curtail load. The thermostats may be configured to collect heating, ventilation and air conditioning (“HVAC”) run time data. The information collected is useful to determine if a demand-response event had an energy reducing effect at a particular home. The consumer uses a very limited web-based application that only allows the consumer to change, view, create and adjust the settings and schedule of the thermostat. The sole purpose of this type of system is to control the settings of the HVAC unit remotely by enabling demand-response events. These systems have limited capabilities to expand and control other devices. For example, if the utility company wanted to include water heaters in the set of demand-response assets they would have to deploy another solution into the home to control them. The utility cannot leverage the asset that has been installed in the premise, effectively limiting the return of their investment. These systems also do not provide for the collection of meter data. With no closed feedback loop, it is impossible to measure the amount of benefit gained from a demand-response event, either on a premise-by-premise basis or in aggregate. This type of system is vendor specific in that it is difficult to adapt the system to use a thermostat or controller device provided by another vendor.  
           [0010]    Comverge, Incorporated manufactures two similar systems. One system includes one-way VHF receivers with the capability for cycling devices such as air conditioners, electric water heaters, pool and irrigation pumps and electric heat for example. The receivers are installed in close proximity to the devices they control. Utilities are able to group devices and control start times and durations to effectively generate demand-response events. This type of system offers no feedback loop making it difficult for the utility to quantify the participation and measure the success of a demand-response event.  
           [0011]    Another system is composed of a two-way control device and module installed at the meter socket, along with the pre-existing meter, that functions as an AMR-enabled device as well as a WAN and local area network (“LAN”) connector. Connectivity between the thermostats and relay devices exist through a LAN created through CEBus power line communications. A LAN using the power lines may require a bridge and an amplifier. A WAN connection may be in the form of a broadband, fiber-optic, RF or dial-up connection. The WAN connection terminates at the module installed on the power meter. The Comverge system does provide flexibility for the utility company to directly control the thermostat. It also provides a price responsive demand response. A server gives the utility company the ability to design and monitor demand response events. The server may also collect and analyze usage data and send pricing information to the control device. The system, however, is limited to two thermostats and two other control devices. Similar to the system provided by Carrier Corporation, the other devices must be compatible with the controller offered by Comverge.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention provides a premise system that is reliable, easy to install, adapt and expand, that provides data to a computing platform detailing the energy usage of the consumer, allowing the utility company to dynamically adjust rates and output levels so as to increase cost savings. In addition the system improves operational efficiencies and allows both utilities and consumers to control energy usage, appliances, and other devices more conveniently. Through the presented system, the consumer may participate in energy management programs such as cost saving initiatives offered by the utility company. The present invention also provides a platform for additional value added services in the future.  
           [0013]    An energy management system according to the invention is designed as a network of devices installed in the home or small office to efficiently make use of HVAC units and other appliances. Devices installed on the network may communicate and transmit information, including energy usage data to a computing platform, for example, located at the utility company. The utility company monitors the usage data as the data is periodically received and is able to generate messages that initiate demand-response events specific to each premise or to a selection or grouping of premises. The utility company uses a computing platform for the repository of data and provides access to the applications for both the utility company employees as well as the consumers. The utility company employees may interact with the computing platform via the applications to control premises, appliances, and devices, in addition to monitoring and reviewing the collected data. The consumer interacting with the application may control appliances and receive detailed energy usage and savings information. In addition to providing the utility company the opportunity to maximize efficiency and cost savings, it provides the consumer with a useful and useable manner for controlling the use of energy.  
           [0014]    One embodiment of the energy management system contains a Local Premise Control Network (“LPCN”), on which various devices and a master controller are installed. A reliable LPCN interconnects all appliances and devices on the premise. Some devices to be installed on the LPCN are built with the necessary connectivity hardware and software to communicate. For other devices that do not contain the required hardware or software, an adapter module may be used to convert the communication protocol of the device to one that is understood by the LPCN. A Wide Area Network (“WAN”) links the premise system to the computing platform. An adapter module can be designed to create connectivity to the WAN no matter the media (e.g., broadband, POTS, Radio Frequency, pager) The LPCN may be a wireless LPCN using radio frequency (“RF”) transmission between the module devices. The LPCN is a fault-reliable network and the gateway may serve as the master controller for the network. Network protocol verifies each message sent and retransmits the message if errors are detected. If the error continues, the data to be transmitted is logged and saved for a future re-transmission and a system alert is sent to the utility company. All faults are logged by the master controller. The computing platform can then request the transmission and fault logs from the master controller as well as notify an operator at the utility company. All adapter modules are arranged and configured in a master-slave relationship. The gateway may serve as the master controller and each adapter module acts as a slave on the network.  
           [0015]    The adapter modules are customizable units that may be added to the system. Adapter modules may include a utility meter signal receiver, hot water heater controller and WAN connector. A signal transmitter, such as an AMR-enabled device, attached to the utility meter transmits meter readings to an adapter module configured to receive data. The data is then forwarded by the adapter module across the network to the master controller via the LPCN. The master controller then forwards the data through the LPCN to the WAN adapter effectively completing the communication between the premise and the computing platform. The master controller itself transmits signals and commands to and receives logged data and other operational data from the adapter modules via the LPCN. Other modules may include such adapters as a serial adapter or a Universal Serial Bus (“USB”) adapter to be connected to other appliances. The flexibility created by the use of the adapter modules allows connectivity despite disparate protocols, physical media and distinct vendor&#39;s equipment.  
           [0016]    In one embodiment, the consumer controls the system through the use of the gateway that manages the HVAC units and all other adapters on the premises. The gateway serves as a thermostat to the HVAC as well as the bridge for communications between the other devices and appliances on the network, such as the HVAC unit and the other adapters like the utility meter module or the WAN adapter module. The gateway designed architecture is similar to that of a typical personal digital assistant (“PDA”), however the gateway may contain resources for high-level software development. The gateway has a large liquid-crystal-display (“LCD”) for displaying a browser-like interface for complex user interactions and experiences. It also contains a standards based operating system that includes developer support for integration with standard information technology (“IT”) system development tools and for dynamic software libraries. The gateway may be a commercially available PDA, such as the Compaq IPAQ or the Sharp Zaurus. The operating systems on these commercially available PDAs may be a Windows Pocket PC on the IPAQ or a Linux based system on the Zaurus. Alternatively the gateway may be in the form of a set-top box running a Linux based operating system. A programmable microcontroller thermostat is used in conjunction with these forms of the gateway, such as the Honeywell Enviracom thermostat. In conjunction with the thermostat hardware, the gateway also mimics all functions normally associated with a traditional thermostat for HVAC units. The gateway may be directly connected to existing HVAC unit controls as well as a temperature sensor using the pre-existing thermostat wires.  
           [0017]    The gateway contains sophisticated software applications to monitor and control the adapter modules on the LPCN as well as log and transmit data across the LPCN to the WAN adapter and out to the computing platform. The gateway logs time, temperature readings, measurements and status data from all LPCN modules. It may also log LPCN fault information and unexpected results and changes to system configuration data. The gateway may also manage control signals and messages for the HVAC unit. The gateway provides the user interface and manages the physical LCD screen, records and timestamps all sensor data, and all system state changes.  
           [0018]    The energy management system presented provides a link to the utility company through the WAN adapter module. The WAN adapter module may be built to utilize any form of data communication media, such as broadband, POTS, RF, two-way paging for example. The link is used to transmit usage data from the gateway to the computing platform. The computing platform, through automated processes or through the direction of an operator may issue messages to the gateway designed to maximize efficiency and cost savings. The link also provides a mechanism for the utility company to upload new applications and diagnostic tools onto the gateway for maintenance and repair. When an error log is transmitted to the server, the server notifies an operator from the utility company, either through a user-interface at a workstation or a two-way messaging device, such as a pager or a mobile phone. The operator may then request more diagnostic data from the gateway or upload new applications to rectify the fault with no inconvenience to the consumer.  
           [0019]    The premise system is advantageous over previous systems because installation of the system is easy and less expensive than that of previous systems without sacrificing reliability. The system is easily adaptable to all premise environments and allows for easy expansion of the system. If a wireless LPCN RF transmission is implemented, there are no wires needed to connect adapter modules. There is also a great degree of freedom in the location of the modular devices making the ease of installation greater. Repeater or relay adapter modules may be implemented to increase connectivity across larger areas.  
           [0020]    Yet another advantageous feature of the presented system is the fault-reliable network used for the LPCN and inter-module communication. When erroneous messages are transmitted, or a message is not received, the master controller will repeat the transmission or log the messages to be sent until a future time, when a connection is re-established. These precautions make the system more reliable and more robust than previous systems.  
           [0021]    Another advantageous feature of the current invention over previous systems is the independence from using a pre-existing PC-based gateway. There is no overlap of energy management applications with other applications a home PC might contain. This prevents the misallocation of computing resources in the gateway at critical times. Applications that share resources are more likely to fail than those that have entirely dedicated and independent resources. This independence also facilitates maintenance and installation. In previous systems, repairing one application without disrupting valuable computing resources already allocated is a difficult and costly task. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]    The foregoing and other features and advantages of the present invention will be more fully understood from the following detailed description of illustrative embodiments, taken in conjunction with the accompanying drawings in which:  
         [0023]    [0023]FIG. 1 depicts a system-wide diagram of a particular embodiment of the energy management system.  
         [0024]    [0024]FIG. 2 is a high-level schematic diagram of a particular embodiment of the energy management system.  
         [0025]    [0025]FIG. 3 is an architecture diagram of a RN module in accordance with an embodiment of the present invention.  
         [0026]    [0026]FIG. 4 is a diagram of the major components of the gateway software in accordance with an embodiment of the present invention.  
         [0027]    [0027]FIG. 5 depicts the application user interface component of the gateway software in accordance with an embodiment of the present invention.  
         [0028]    [0028]FIG. 6 is a diagram of the main application process component of the gateway software in accordance with an embodiment of the present invention.  
         [0029]    [0029]FIG. 7 is a diagram of the application infrastructure library component of the gateway software in accordance with an embodiment of the present invention.  
         [0030]    [0030]FIG. 8 is a diagram of the watchdog process component of the gateway software in accordance with an embodiment of the present invention.  
         [0031]    [0031]FIG. 9 is an architecture diagram of the reliable network communications library.  
         [0032]    [0032]FIG. 10 is an architecture diagram of the thermostat hardware interface of the gateway application.  
         [0033]    [0033]FIG. 11 is an architecture diagram of the gateway hardware in accordance with an embodiment of the present invention.  
         [0034]    [0034]FIG. 12 is a front view of the gateway in open mode in accordance with an embodiment of the present invention.  
         [0035]    [0035]FIG. 13 is a front view of the gateway in closed mode in accordance with an embodiment of the present invention.  
         [0036]    [0036]FIG. 14 depicts an alternative embodiment of the energy management system in which the gateway serves as a slave to a home-gateway master controller. 
     
    
     DETAILED DESCRIPTION  
       [0037]    [0037]FIG. 1 depicts a system architecture detailing an embodiment of an energy management system  1 . A home or office  5  is shown containing a gateway  10 , a HVAC unit  15  connected to HVAC controls  20 , a utility meter  25 , a utility meter reading adapter module  30  and a WAN adapter module  35 . The energy management system  1  sends and receives signals, messages, commands, and data to energy company servers  40  through a two-way pager network  42  or a modem/broadband connection  50 .  
         [0038]    In one embodiment, the gateway  10  serves as a master controller for the adapter modules  30 ,  35  located on a reliable network (“RN”)  55 . The gateway  10  transmits and receives RF signals across the RN  55  to and from the adapter modules  30 ,  35 . The gateway  10  issues commands to the adapter modules  30 ,  35  based on data received from other adapter modules  30 ,  35 . The gateway  10  also functions as a micro-controller based thermostat for the HVAC unit  15  over the pre-existing HVAC controls  20  by mimicking the functionality of a typical programmable thermostat. The gateway is capable of responding to demand/response commands sent from computing platforms  40 . The gateway  10  logs data, transmitted from the adapter modules  30 ,  35  as well as data from the thermostat function that may then be uploaded to the computing platforms  40  at specific time intervals. Usage data may include, but is not limited to temperature, thermostat settings and user input commands.  
         [0039]    The utility meter  25  is connected, as a device, to the utility meter adapter module  30 . In this embodiment, the utility meter reading adapter module  30  is designed to work with several pre-existing models of AMR-enabled utility meters. Examples include, but are not limited to an AMR-enabled Schlumberger meter or an AMR-enabled General Electric meter. The utility meter adaptor module  30  can be configured to function with utility meters using differing AMR-enabling technologies. The utility meter adapter module  30  broadcasts RF signals containing electricity usage data output by the AMR-enabled utility meter  25  through the RN  55  to the gateway  10 .  
         [0040]    The WAN adapter module  35  serves as a link between the gateway  10  via the RN  55  and the computing platforms  40 . The WAN adapter module  35  may consist of a dial-up modem/broadband connection  50  or a two-way pager network  42  connection as a conduit between the computing platforms  40  and the gateway  10 . A pager network operator  45  receives and transmits signals from the WAN adapter module  35  and the computing platforms  40 . The computing platforms  40  log and evaluate data transmitted from the RN  55  allowing for dynamic and efficient output of energy resources.  
         [0041]    Data from the energy management system  1  may be uploaded to the computing platforms  40 . This allows the utility company, through its servers  40  to monitor and evaluate the incoming data sent from the energy management system  1  through the WAN  37 . The data transmitted is then used to revise the energy management scheme at a system-wide level or at a premise-by-premise level. The computing platforms  40  then respond by transmitting signals that initiate cost-saving programs specific to each premise. The computing platforms  40  may also dynamically load software packages and drivers to the adaptor modules  30 ,  35  over the WAN  37  through the WAN adapter module  35  and the RN  55 . This facilitates maintaining and updating the energy management system software resident on the adapter modules  30 ,  35  from both a time and cost perspective.  
         [0042]    [0042]FIG. 2 is a high-level component diagram of one embodiment of the energy management system  1 . The RN  55  provides for communication between the gateway  10 , the utility meter reading adapter module  30 , a temperature sensor adapter module  60 , a third-party LAN adapter module  65  and a WAN adapter module  35 . The adaptor modules  30 ,  35 ,  65  link devices and other networks to the RN  55  of the energy management system  1 .  
         [0043]    The gateway  10  serves as both the micro-controller based thermostat and as the master controller for the adapter modules  30 ,  35 ,  65  on the RN  55 . The gateway  10  is the main user-interface in the home to the energy management system  1  and is capable of controlling appliances and devices  85  located on the RN  55 . The HVAC unit  15  is connected to the gateway  10 . The gateway  10  serves as a traditional programmable thermostat. The user inputs commands and program settings into the gateway  10 . The gateway  10  transmits the commands to the HVAC unit  15  and the HVAC unit  15  responds by changing its mode of operation. The gateway  10  may also transmit commands to the adapter modules  30 ,  35 ,  65  which, in turn, forward the commands to the appliances, devices. The gateway  10  receives data from the adaptor modules  30 ,  35 ,  65  and stores the data for periodic upload to the computing platforms  40 .  
         [0044]    The third-party LAN adapter module  65  provides a link from the RN  55  to another third party LAN  75 . The third-party LAN adapter module  65  allows communication between a distinct network (e.g. networked sensors)  80  and other adapter modules  30 ,  35 ,  65  that reside on the RN  55 . The third-party LAN  75  may consist of a home security system, or a home management or automation network. The gateway  10  can control and monitor, through the third-party LAN adapter module  65 , the other network  80  and appliances and devices  85 . The third-party LAN adapter module creates a single-point monitor and control device for the other network  80  and appliances and devices  85 . The third-party networks  75  typically consist of control modules  70  connected to the appliances and the devices  85 , such as HVAC units, lights, or security sensors.  
         [0045]    The utility meter adapter module  30  takes the output of the AMR-enabled utility meter  25  and transmits RF signals containing electricity usage data to the RN  55 . The gateway  10  receives and stores the usage data until it is uploaded to the computing platforms  40 . The data transmitted to the computing platforms  40  allows the utility company to dynamically revise its energy resources and outputs based on the level of energy used and the strain on the system created by each energy consumer.  
         [0046]    The temperature sensor adapter module  60  monitors and transmits an ambient temperature to the gateway  10  via the RN  55 . As with a conventional HVAC configuration, the temperature reported by the sensor  60  and the temperature threshold setting stored by the user through the thermostat function of the gateway  10  determines the HVAC unit&#39;s  15  state of operation. The gateway  10 , acting as a thermostat, compares the data reported by the temperature sensor  60  with the temperature threshold to determine the mode of operation of the HVAC unit  15 .  
         [0047]    The WAN adapter module  35  is a link between the gateway  10  and the computing platforms  40  using a 2-way pager network  42  or a dial-up modem/broadband connection  50  as means for connecting the two. Other media are also available to provide a connection to the computing platform, such as POTS, RF and digital cellular networks. The computing platforms  40 , using sophisticated algorithms and software tools, analyze the uploaded data from the energy management system  1 . The platform operator may issue messages and commands pertaining to energy savings and cost savings programs through the WAN  37 , using the WAN connection  50  or two-way pager network  42 , to the gateway  10  via the RN  55 .  
         [0048]    In one embodiment, the gateway  10  serves as the master device on the RN  55  and the adapter modules  30 ,  35 ,  65  serve as slaves receiving commands from the gateway  10 . During initialization the adapter modules  30 ,  35 ,  65  broadcast identifications (“IDs”) and the gateway  10  receives and stores the IDs in memory. Thereafter, the gateway  10  communicates with adapter modules  30 ,  35 ,  65  from which IDs have been received during initialization. The gateway  10  also detects faults and outages of the adapter modules  30 ,  35 ,  65 .  
         [0049]    The RN  55  is designed as a fault-reliable network. The gateway  10 , serving as master controller, audits communications using CRC or equivalent techniques and issues retransmit commands if there are errors or faults in the RN  55 . If the fault persists, the data is logged by the slave adapter module  30 ,  35 ,  65  for future re-transmission. The gateway  10 , serving as the master controller logs all faults and attempts to retransmit at periodic intervals. If a fault condition persists a system alert is issued by the gateway  10  to the computing platforms  40 . The sophisticated software of the computing platforms  40  can then evaluate the fault and initiate a course of action.  
         [0050]    Referring to FIG. 3, each adapter module on the RN  55  contains a RN module  100 . The RN module  100  allows the adapter module to communicate across the RN  55  to the master-controller and other devices. The RN  55  is configured as a master-slave network. The firmware installed on the adapter modules dictates the device&#39;s role as a master or a slave. A reliable network host interface  105  communicates high-level functions to the gateway  10  or adapter modules  30 ,  35 ,  65 . A micro-controller  110  implements a RN stack and communicates with a RN physical layer  115 . The RN physical layer  115  may be, for example, a radio frequency network or power line systems. In one embodiment, a radio frequency emitting chipset, such as one from RFWaves, is used. The RFWaves chipset provides a low-cost, 2.4 GhZ world-wide license free band frequency, a raw data rate of up to 1 Mbps and offers versatile operation voltages and communication ranges. The RF chipset has low power consumption, a simple module architecture with minimal external components and provides for a standard encrypted query protocol. The RF chipset is a cost effective and efficient solution for the RN physical layer  115  that connects the gateway  10  and the adapter modules  30 ,  35 ,  65 .  
         [0051]    With respect to FIG. 4, the software application  120  architecture of the gateway  10 , designed around a PDA, is built for the interaction of several major components. The application user interface  125  sends commands to the main application process  130 . The main application process  130  sends and receives data from a watchdog process  135 , that monitors the application process, and the application infrastructure library  140  which supports the main application process  130  with various lower level functions.  
         [0052]    The reliable network communications library  145  provides an interface for the main application process  130  and the watchdog process  135  via the application infrastructure library  140  to communicate with devices in the RN  55  or the WAN. The reliable network communications library  145  is linked with the application infrastructure library  140  and provides a low-level interface for formatting messages for a delivery to and from the RN  55 . The reliable network communications library  145  also monitors the RN  55  for error conditions. If an error is detected, the reliable network communications library  145  transmits a message to the event logger in the main application process  130 . The hardware interface  150  is implemented as a library that is linked to the application infrastructure library  140 . The hardware interface  150  enables the gateway software  120  to send and receive data from the thermostat hardware, such as temperature sensors and the HVAC controls  20 .  
         [0053]    Regarding FIG. 5, the application user interface  125  controls the user interactions with the gateway software  120  including information formatted and displayed on the LCD screen, and user input retrieved from physical switches. The application user interface  125  includes simple scripting and validation functions  155  as well as a mechanism to send commands to the main application process  130 . The application user interface  125  is implemented as a mini-browser  160  with application screens implemented as pages. The mini-browser  160  formats applications for display and captures user input. The scripting functions  155  implement dynamic content display in the application and validate user input. The graphics functions  165  render graphical information to the LCD screen.  
         [0054]    The request dispatcher  170  sends commands to the main application process  130  as a result of user input and delivers the response from the main application process  130  to the user interface. The installer application  175  includes the application screens or pages that implement the initial installation and setup steps, and subsequent installation and setup steps for future devices or adapter modules, required to configure the gateway  10 . The application user interface  125 , through the main application process  130 , discovers the available devices on the RN  55 , downloads information from the computing platforms  40  and stores configuration settings. The thermostat application  180  includes the application screens or pages that implement the interface between the user and the energy management system  1 . It relies on the main application process  130  to respond to commands to control or read the thermostat hardware and to initiate actions on other devices in the RN  55 .  
         [0055]    Referring to FIG. 6, the main application process  130  is composed of sub-components that may include a task scheduler  185 , a request handler  190 , a device discovery sub-component  195 , an event logger  200 , and a rules engine  210 . The task scheduler  185  stores data concerning events scheduled to execute in the future, for example, at a pre-defined time, the task scheduler  185  initiates an event sending a control signal to a device. The request handler  190  responds to requests received from the application user interface  125  or the computing platforms  40 . The device discovery sub-component  195  searches for devices connected to the RN  55  by sending messages and storing the responses to persistent storage. The event logger  200  listens for and stores events that occur on the RN  55 , such as faults and state changes. The event logger  200  also logs events received from the thermostat hardware.  
         [0056]    The rules engine  210  monitors the event logger  200  for specific events and initiates subsequent actions when pre-defined rules are satisfied. Examples of rules and actions defined in the rules engine include, but are not limited to: if there is no motion detected in a room for 30 minutes, turn off the lights in that room; if the efficiency of an oil burner falls outside of defined parameters, send a message to the energy management service to schedule service; if the utility meter has not reported data in two hours, then transmit a message to the energy management system to schedule service; if a compressor is running and only has a short time remaining in its cycle and a second compressor is about to begin running, delay the second compressor until the first compressor cycle is complete; if the weather forecast indicates a high temperature, schedule an energy management event to raise the indoor temperature at which the air conditioner begins cooling; if the current price of energy is peaking, reduce power consumption of all devices to a pre-defined threshold; if the humidity in a room falls below a pre-defined parameter, turn on the humidifier. The rules can be defined to include several different parameters. The task scheduler  185 , the request handler  190 , and the rules engine  210  all rely on the other sub-components of the main application process  130 . The sub-components of the main application process  130  rely on the application infrastructure library  140  to complete their functions, such as communications, persistence, and message protocol translation.  
         [0057]    Referring to FIG. 7, the application infrastructure library  140  supports the main application process  130  with lower level functions such as configuration management, message protocol resource management, persistent storage and network communications. The reliable network communications library  145  provides an interface for the application infrastructure library  140  to communicate with devices on the RN  55 .  
         [0058]    A configuration manager  220  controls all configuration information for the gateway application  120 . The gateway configuration may be changed through a variety of methods, including through the installation application, the rules engine  210 , or remotely from the computing platforms  40 . The configuration manager  220  relies on the persistence manager  225  to store configuration information. It also uses the communications manager  230  to communicate with computing platforms  40  or with other devices on the RN  55 . The protocol handler  235  stores definitions of message formats that are understood by the devices on the RN  55 . The protocol handler  235  completes all translations required to forward messages from one device to another. The request dispatcher sends commands to the main application process  130  as a result of messages received from the devices on the RN  55  or from the computing platforms  40 . The request dispatcher  240  uses the communications manager  230  to interface with the RN  55 .  
         [0059]    The communications manager  230  converts messages from the main application process  130  or the watchdog process  135  into messages that are understood by the RN  55 . The resource-manager  245  monitors and controls any PDA operating system resources that are needed by the gateway application  120 . If a resource is low, it can gather any un-used or low-priority resources to avoid a system failure. The resource manager  245  operates in conjunction with the persistence manager  225  to supervise memory and non-volatile storage. The persistence manager  225  stores and retrieves data from non-volatile storage.  
         [0060]    Regarding FIG. 8, the watchdog process  135  may be implemented as a separate task, separate threads or a separate process based on the capabilities of the PDA Operating System. The software update manager  250  may receive periodic messages from the computing platforms  40  detailing updates to the gateway application software  120 . It installs the updates and schedules an application reboot using a boot manager  255 . The software update manager  250  uses the application infrastructure library  140  for communications and persistence. The boot manager  255  monitors the main application process  130  to ensure that the main application process  130  is not online. If the boot manager  255  detects the main application process  130  is available or a system fault has occurred, the boot manager  255  reboots the gateway application  120  or the entire gateway  10 .  
         [0061]    Referring to FIG. 9, the reliable network communications library  145  is implemented as a separate library that is linked with the application infrastructure library  140 . The subcomponents of the reliable network communications library include a master controller  260 , a RN event logger  265 , a messaging abstraction layer  270 , and a collection of low-level functions  275 . A master controller sub-component  260  monitors the RN  55  for error conditions and devices with which it can communicate. If a RN error is detected the RN event logger  265  forms a message to be dispatched to the event logger  200  in the main application process  130 . A messaging abstraction layer  270  provides an abstract interface for formatting, sending and receiving messages on the reliable network  55  and for using the reliable network&#39;s  55  protocol. The communications manager  230  of the application infrastructure library  140  uses the messaging abstraction layer  270  to send and receive application level messages on the RN  55 .  
         [0062]    Regarding FIG. 10, the hardware interface component of the gateway application  120  is implemented as a separate library that is linked with the application infrastructure library  140 . The hardware interface  150  enables the gateway application  120  to interact with temperature sensors  60  and the HVAC controls  20  directly connected to the gateway in this embodiment. The data functions sub-component  280  enables the gateway application  120  to change data values in the thermostat or HVAC controller hardware such as heat and cool setpoints or schedule times. The notification functions sub-component  285  provides updates from the thermostat or HVAC controller hardware about changes in the hardware state, data measured by temperature sensors, or hardware faults detected. The low-level device I/O functions subcomponent  290  sends and receives instructions and data to and from the thermostat and HVAC controller hardware via serial communications, by manipulating hardware registers, or other similar means  
         [0063]    Referring to FIG. 11, the gateway  10  is designed around a PDA architecture with added functionalities, such as a thermostat function for controlling the HVAC unit  15 . The gateway hardware extends the PDA  300  through additional interface hardware  305  such as an HVAC controller  310 , a temperature sensor  315  and a RN module  100 . The HVAC controller  310  implements a universal interface to a range of possible HVAC control situations including common control types such as various heat pumps and multizone HVAC control. The resultant gateway  10  is a PDA that has specific hardware features enabling both thermostat and gateway application  120  functions. This device replaces the pre-existing thermostat.  
         [0064]    Referring to FIG. 12, an embodiment of the gateway  10  in open mode is shown with a hinged cover  320  fully open. The gateway  10  contains a faceplate  325  having openings for a LCD screen  330 , operation buttons  335 , a message indicator  340  and a jog-dial  345 . The LCD screen  320  displays configuration and status information of the energy management system  1  to the user in a browser-like interface. In open mode, the LCD screen  330  displays in-depth menus for schedule programming, diagnostics, and several other functionalities. The gateway  10  contains resources to support high level software development. The gateway  10  utilizes a well-supported standards-based operating system that includes developer support for integration with standard IT system development tools and support for dynamic software libraries. The operation buttons  335  are a means for a user to navigate and input commands highlighted on the LCD screen  330 . The jog-dial  345  allows the user to navigate through menus and options as a means of controlling and monitoring the energy management system  1 . The hinged cover  320  of the gateway has openings aligned with critical display areas of the LCD screen  330  as well as an opening for the jog-dial  345  to allow for operation of the thermostat functions of the gateway  10  while the hinged cover  320  remains closed.  
         [0065]    Referring to FIG. 13, the front-cover obscures a large portion of the LCD screen  330 . In closed mode, the gateway  10  operates as a traditional thermostat. The user adjusts the heating or cooling temperature by rotating the jog-dial  345  until the desired temperature setting is reached. Rotating the jog-dial  345  will interrupt and override any pre-programmed setting of the gateway  10 . In an embodiment, the exposed portion of the LCD screen  350  alternately displays the current temperature and current time. Also visible in closed mode is the schedule  355  of heat and cool threshold temperatures for pre-programmed periods such as wake, leave, return and sleep. The gateway  10  may also notify the user, by an audible and visual notification, that a message has been received from the computing platforms. The message indicator  340  will light up upon receiving a message. A range of customizable audible and visible notifications may be implemented depending on the importance or severity of the message. Less urgent messages may use a softer tone or display, for example.  
         [0066]    In an alternative embodiment, as depicted in FIG. 14, a home-gateway  360  is the master controller on the RN  55  and replaces the WAN adapter module  35 . The home-gateway  360  is connected to a home-gateway adapter module  365 . The home-gateway adapter module  365  transmits and receives signals across the RN  55  to the gateway  10  and adapter modules  30 ,  365 . The gateway  10  is a slave device in this configuration acting as the thermostat. The home-gateway adapter module  365  is linked to the computing platforms  40  through a bi-directional broadband ISP connection  370 . A two-way pager network  42  may be used for redundancy and reliability if the broadband connection  370  fails. A pager network operator  45  receives and transmits signals from the home-gateway adapter module  365  and the computing platforms  40 .  
         [0067]    Although the embodiments described herein discuss thermostat, gateway and master controller functionality, it should be appreciated by those skilled in the art that such functionality can be provided in a system according to the invention with separate and distinct functional elements (i.e. a separate thermostat, separate gateway and separate master controller), or such functionality can be implemented by combining these elements (e.g. thermostat and gateway functionality in a discrete component with or without the master control functionality, or the gateway and thermostat as separate components with one or the other including the master controller).  
         [0068]    Although the embodiments described herein discuss a gateway and a master controller that may emulate the functionality of a wall-mounted thermostat, it should be appreciated by those skilled in the art that the gateway or master controller may be a mobile device, such as a commercial hand-held PDA, for example the Compaq IPAQ, or the Sharp Zaurus. The gateway or master controller may also be a detachable wall unit, capable of monitoring and controlling the system while being carried by a user or technician.  
         [0069]    Although the embodiments described herein discuss an energy management system targeted to utility company services, it should be appreciated by those skilled in the art that the services may include other utility systems, (e.g. water services, sewage services, gas services or electricity services), or other command and control systems (e.g. pool monitoring systems, asset performance monitoring services).  
         [0070]    Although the embodiments described herein discuss networks utilizing specific media protocols such as RF, dial-up modem, POTS, two-way paging and broadband, it should be appreciated by those skilled in the art that the media of the WAN connection or the RN may include other forms of media (e.g. power lines, RF, dial-up modem, POTS, two-way paging, broadband, digital wireless broadband, and any hybrid combination thereof).  
         [0071]    It should be apparent to those skilled in the art that many other combinations and configurations of the above mentioned details and embodiments are possible without departing from the true underlying principles of the invention.