Abstract: The invention provides a method for providing an indication of the occurrence of events within a database system. The database system stores data accessible by a plurality of users and in a plurality of data formats. The method comprises the steps of periodically reading a storage location within the database, detecting a data structure stored in the storage location and reading the data structure. The method further includes the steps of converting the data structure from the first data format to a second data format and providing the indication to at least one user, the indication including at least a portion of the data structure.

Abstract: A networked system having a wide variety of applications and particularly applicable to facilities management systems has multiple levels of software in processing nodes. The levels include a "features" processing level which communicates requests for data to a software object level containing databases of processes and attributes and database managers. The database managers in the software object level operate to provide data to the high level features in the same format. The software object level communicates with a hardware object level which also contains databases and database managers to mask differences between operational hardware units. By categorizing operational units by type, additional units of a known type can be added with only low level hardware object database changes. Adding units of a new type is facilitated by software changes confined to the lower level hardware and software objects, avoiding software changes at high level features.

Abstract: A networked system having a wide variety of applications and particularly applicable to facilities management systems has multiple levels of software in processing nodes. The levels include a "features" processing level which communicates requests for data to a software object level containing databases of processes and attributes and database managers. The database managers in the software object level operate to provide data to the high level features in the same format. The software object level communicates with a hardware object level which also contains databases and database managers to mask differences between operational hardware units. By categorizing operational units by type, additional units of a known type can be added with only low level hardware object database changes. Adding units of a new type is facilitated by software changes confined to the lower level hardware and software objects, avoiding software changes at high level features.

Abstract: A pattern recognition adaptive controller configured to dynamically adjust proportional gain and integral time control parameters to minimize integrated absolute errors between a setpoint temperature and a monitored temperature in an HVAC system. The pattern recognition adaptive controller receives a sampled signal representative of the temperature and determines a smoothed signal based on the sampled signal. The controller characterizes a disturbance in the smoothed signal by a damping factor and a closed loop response time. When a significant load disturbance or setpoint temperature change occurs, the controller estimates an optimal gain based on the damping factor, and an optimal integral time based on the response time. The estimated optimal gain and estimated optimal integral time are used to determining a new gain and a new integral time values, to which the control parameters of the controller are then set.

Abstract: A method and apparatus for controlling an environmental parameter is disclosed. The apparatus includes a source of energy controlled air and a source of external air. A damper determines the amount of external air and energy controlled air provided to the room. A control circuit controls the position of the damper in response to an enthalpy calculator. The enthalpy calculator includes a temperature sensitive resistor having a resistance RT and a relative humidity sensitive capacitor wherein the capacitance of the relative humidity sensitive capacitor is CS. An electronic circuit includes RT and CS and provides an output h: ##EQU1## The method includes the steps of providing energy controlled air and external air. The temperature and humidity of the external air are sensed, and the enthalpy is calculated using the equation ##EQU2## where t is the temperature and RH is the relative humidity. The amount of external air provided is adjusted using the calculated enthalpy as a parameter.

Abstract: A method and apparatus for controlling the environment within an enclosed space is provided. The apparatus monitors environmental variables, and responsive to the values of the environmental variables, estimates the rate at which a gas is being generated within the enclosed space. The apparatus generates control signals to control devices based on the rate at which the gas is being generated within the enclosed space. In the preferred embodiment, the apparatus estimates the rate at which carbon dioxide is being generated in the enclosed space. Based on the estimated carbon dioxide generation rate, the apparatus may be configured to control an HVAC system, a comfort control system, lights, alarms or other devices.

Abstract: A network system having a wide variety of applications and particularly applicable to facilities management systems includes network controllers which continuously process data related to building and industrial, environmental, security and other automated system controls. Each network controller has a network address indicative of a communication link to which the network controller is connected, a local address and a node drop ID to determine whether the network controller is a configured or non-configured device. Data stored in an archive device is downloaded to a destination network controller in the absence of a routing table in the destination network controller by transmitting a download request message from the archive device to an intermediate network controller with a routing table. The intermediate network controller assumes control of the download request by transmitting the message to the destination controller.

Abstract: The present invention relates to an intelligent transient eliminator which allows a gas ignition system to prevent gas valves from being turned off by a pressure switch in response to a transient pressure wave. The transient eliminator is preferably provided in a HVAC unit or furnace which burns a fuel such as natural gas. An ignition control system employing an intelligent transient eliminator provides a secondary relay across the pressure switch. The secondary relay is controlled by a signal to an ignitor in the furnace. The secondary switch is tested before energizing the inducer blower in the system.

Abstract: A damper assembly gear system for interchangeably carrying either airfoil damper blades or single-ply damper blades. A first embodiment, in which the damper blades rotate in opposition to one another, includes a group of gear bodies, each of which includes a tab structure, including both airfoil tabs and single-ply tabs, for mounting both types of damper blades. The airfoil tabs are shaped to match an airfoil damper and are spaced apart such that an airfoil damper can be inserted between and gripped by the airfoil tabs. Single-ply tabs are located between the airfoil tabs, shaped to match a single-ply damper and spaced apart such that a single-ply damper can be inserted between the single-ply tabs and gripped thereby. An alternative embodiment allows the system to be used in conjunction with both opposed and parallel damper assemblies. First, this embodiment includes two types of gears, blade gears and idler gears.

Abstract: A tombstone style machine tool fixture for machining valve castings having hexagonal flanges on each end and a bonnet intermediate the ends of the castings, the fixture including a column having a number of work stations mounted on the column, each work station including a main support plate, a number of hydraulic cylinder assemblies mounted on said support plate, a clamp plate supported by said hydraulic cylinder assembly for movement between open and closed positions with respect to the main support plate, a locating plate removably mounted on said clamp plate and having a hexagonal notched block mounted on each end of the locating plate for engaging the flanges on the casting and an alignment block mounted on said locating plate intermediate said notched blocks to align the casting in the notched block and a clamp bar mounted on said column for seating the flanges in said notched blocks.

Abstract: The present invention relates to a diagnostic system for use in a network control system. The diagnostic system is preferably utilized to analyze VAV box performance in an environmental control system such as a network facilities management system. The diagnostic system advantageously allows the serviceperson to perform diagnostic tests on VAV boxes from a remote location. Flat box warnings, starved box warnings, box excessive damper hysteresis warnings, oversized box warnings, damper stroke out of bounds warnings, as well as other box and damper warnings may be provided by the diagnostic system. Preferably, the diagnostic system formats the air flow data so that it can be displayed for graphing. The diagnostic system causes individual controls to adjust the damper positions. Air flow parameters for each position are communicated to the remote location.

Abstract: A networked system having a wide variety of applications and particularly applicable to facilities management systems has multiple levels of software in processing nodes. The levels include a "features" processing level which communicates requests for data to a software object level containing databases of processes and attributes and database managers. The database managers in the software object level operate to provide data to the high level features in the same format. The software object level communicates with a hardware object level which also contains databases and database managers to mask differences between operational hardware units. By categorizing operational units by type, additional units of a known type can be added with only low level hardware object database changes. Adding units of a new type is facilitated by software changes confined to the lower level hardware and software objects, avoiding software changes at high level features.

Abstract: An instrumentation interface circuit controlled by a microprocessor of a data acquisition system enables identification of the type of input/output devices that are connected to its inputs through a systematic analysis of the characteristics of the connected devices, the systematic analysis including monitoring the current through and the voltage across the devices as different drive signals are applied to the connected devices, the interface circuit including a conditioning circuit having a drive circuit which is controlled by the microprocessor for providing the drive signals, a current sensing circuit for sensing the load current flowing through the connected device, a voltage sensing circuit for sensing the voltage across the connected device, and a switchable feedback circuit which is controlled by the microprocessor to selectively feed back the load current or the sensed voltage to the input of the drive circuit to establish the drive signals for the connected device.

Abstract: A circuit for producing signals representative of at least two flame current levels is disclosed herein. The circuit includes two electrodes locatable in a flame, where a voltage potential is set up between the electrodes, and the current flow is measured therebetween (flame current). The circuit includes an amplifying portion for amplifying the flame current and applying a signal to a microprocessor. The microprocessor samples the signal and outputs a signal representative of the flame current level.

Abstract: The present invention relates to a method for increasing the useful life of a shape memory alloy (SMA) actuator, wherein the SMA element contracts on heating and elongates on cooling under an applied stress and that property is used as an actuating technique. More specifically, the present invention relates to the cooling aspect of the cycle and maintaining a martensite strain on the actuator SMA element at less than about 3% by limiting the upper stress on the element. In the most preferred embodiment, the element is a ribbon actuator prepared from a nickel-titanium SMA alloy.

Abstract: A facility management system including facility control devices, monitoring arrangements, and actuating arrangements is provided. Each facility control device is connected to every other facility control device through a group of Integrated System Digital Network (ISDN) bearer channels (B-channels). Each facility control device is further connected to every actuating and monitoring arrangement through an ISDN data channel (D-channel). This facility management system allows each facility control device to communicate with all other facility control devices without any intervening communication processing by other facility control devices. Thus, this system does not create the throughput bottlenecks and reliability problems inherent in systems which necessitate such intervention. The components of this facility management system are networked over telephone lines, thus, the system does not require the installation of separate network lines between each system component.

Abstract: A signal isolation apparatus has a first transformer with a primary winding tap receiving an input signal and another primary winding tap receiving a first oscillating signal. A second transformer has a primary winding tap receiving the input signal and another primary winding tap receiving a second oscillating signal. The second oscillating signal is out of phase (typically 180 degrees out of phase) with the first oscillating signal. A rectifier electrically connected between a first secondary winding tap of the first transformer and a first secondary winding tap of the second transformer has a high output terminal and a low output terminal, the low output terminal being referenced to a second secondary winding of the first and second transformers. A signal across the high and low output terminals is an output signal galvanically isolated from the input signal with the same electrical characteristics as the input signal.

Abstract: A load shedding apparatus for limiting peak electrical demand in an electrical system to a target level through load shedding. The apparatus employs predictive control logic to estimate the amount of energy that needs to be shed in a predetermined future period. Preferably, the load shedding apparatus forecasts the amount of energy require in a predetermined future period by analyzing current energy consumption, current load shedding, and error factors indicative of the random energy demand characteristics of the electrical system. The apparatus estimates the amount of energy that needs to be shed in view of the forecast of the amount of energy required in the predetermined future period. The apparatus selects non-essential loads for shedding until the estimated amount of energy that needs to be shed is reached. The apparatus transmits shed control signals to selected devices within the electrical system to disconnect the selected devices.

Abstract: A capacitance humidity sensor according to the invention has a film core which is in contact with a pair of conductive layers bonded to opposite faces of the core. The core is made of a polyimide having a dielectric constant which varies substantially linearly with humidity and which includes at least one ether linkage in the dianhydride portion thereof. The polyimide may also include at least one ether linkage in the diamine portion thereof and/or at least one fluorine atom in the diamine, dianhydride or both the diamine and dianhydride portions thereof.

Abstract: A motor controller for a recreational vehicle (RV) heating system is disclosed. The motor controller regulates the amount of current supplied to an electrical motor in a blower of the heating system in response to the operating voltage and a signal from a microprocessor. The microprocessor operates a linear program in response to a cyclical signal provided at a reset terminal. The motor controller includes a locked rotor sensor which determines if the motor is turning. The motor controller utilizes a resistor as a voltage limiting means and a field effect transistor (FET) for bypassing the resistor. The microprocessor and motor controller provide a highly reliable and readily adaptable heating system which is not disadvantageously susceptible to variations in the supply voltage.