Abstract: A graphics display has the capability of displaying both alpha numeric images and graphic images and properly blending these images. The blending is done timely and efficiently while still utilizing a memory structure wherein the graphic pixmap is stored in one memory and the alpha pixmap is stored in a second memory. A priority value is assigned to each pixel of the display. The priority value indicates what the desired display structure is to be. The priority value, the graphic pixel value, and the alpha pixel value are all polled and the appropriate pixel value is transmitted to a display device.

Abstract: In a process control system having a redundant multilayer hierarchical structure, each node of a layer being redundant sequence of events inputs are received from field devices by an input/output processor (IOP). The IOP is a digital input sequence of events (DISOE) IOP, the IOP being the lowest layer of the hierarchical structure. The IOP interfaces with a controller at the next layer of the hierarchy. A method for reliably maintaining a sequence of events function during a failover of any of the redundant nodes, comprising the steps of maintaining a log, a circular list, by the local DISOE. The circular list is a rolling log of all sequence of events data for a predefined time period. When a failover occurs, the new primary commands an event recovery. The event recovery process freezes the log and uses the information in the log to recreate the events data. The freeze operation inhibits background purge activity for the log thereby avoiding the deletion of information past the defined time.

Abstract: The method allocates a demanded amount of power to a plurality of power output apparatus, each power output apparatus having characteristic curves associated therewith, such that each of the power output apparatus supplies a portion of the demanded power, and the total power outputted from the plurality of power output apparatus results in a minimum cost for generating the power as a function of a plurality of constraints. Data is entered for each of the power output apparatus into a controller. Optimal solutions are generated for all valid possible output power demands using an optimization by parts technique within output power bounds of each of the power output apparatus. The solutions indicate the portion of power each power output apparatus is to supply to provide the total power demanded at minimal cost and emissions output at or less than predetermined levels. The solutions are stored in tables within a storage unit of the controller.

Abstract: A process control system which includes at least one manipulated variable and at least one controlled variable, provides a method for robust control of a process. Predetermined constraints of the manipulated variables and the controlled variables, and the present values of the manipulated variables are obtained. New values are calculated for the controlled variables for a predetermined number of points in the future, such that the values of the controlled variables are within the predetermined range thereby obtaining an optimal robustness of the resultant controller. The manipulated variables are also calculated to be within predetermined constraints, and the controlled variables to fall within a predetermined range when controllable. From a plurality of solutions, a most robust solution is selected. Then the manipulated variables are adjusted to cause the process control system to drive the values of the controlled variables to the calculated values.

Abstract: Low cost components of a circuit board are calibrated in a test fixture to the same accuracy as a single high precision resistor, thereby eliminating the need for high precision, high cost components. The current through the resistor on the circuit board under test is ascertained by determining the current through the resistor by measuring the voltage of the high precision resistor. The voltage across the resistor under test is measured by a controller on the circuit board, thereby being able to calculate a high accuracy value for the resistor. The digital to analog converter (DAC) on the circuit board is calibrated by placing digital load values, or inputs, to the DAC and measuring the voltage across the corresponding calibrated resistors. Two values of inputs are used which define a line thereby calibrating the DAC.

Abstract: When an interlock trip condition occurs, a back tracing of interlock logic occurs by examining input signals to an output gate of the interlock logic to determine which input signal caused the interlock trip condition. If the input signal is a predetermined interlock condition, that signal is deemed to be the cause of the interlock trip, saved and displayed. If the input signal is the output of another gate, then the inputs to that gate are examined to determine which input signal caused that gate to switch state. This process is repeated until a predetermined interlock condition is found which has switched state. By knowing the structure of the interlock logic and knowing the state of logic signals outputted from the interlock logic, the determination is made and saved such that even if the predetermined interlock condition that caused the interlock trip subsequently changes state as a result of placing the device in a safe state, the cause of the interlock trip is ascertained and saved by this method.

Abstract: The present invention relates to a distributed fuel system, wherein a plurality of fuel tanks used for storing fuel are distributed in different locations.The fuel tanks are connected to each other via a manifold which permits fuel to flow therein. The distributed fuel system includes a plurality of control components interposed at predetermined points of the manifold to permit or restrict the flow of the fuel contained in the manifold in response to control signals. A method for distributing the fuel between the fuel tanks to achieve predetermined levels in each of the fuel tanks comprises the steps of determining the status and condition of the fuel system. The functions to be performed are then selected. Based on the system status and the functions to be performed, the configuration of the control elements is selected to perform the functions to be performed.

Abstract: In an aircraft having an aircraft tracking system (ATS), the aircraft being a monitoring aircraft, the monitoring aircraft interrogates target aircraft in the vicinity of the monitoring aircraft in order to determine potentially dangerous situations. The target aircraft responds to the interrogations with parameter information which includes identification (ID). A method of interrogating the target aircraft comprises the steps of receiving unsolicited signals from the target aircraft in the vicinity of the monitoring aircraft. The received unsolicited signals are received by the monitoring aircraft at a first power level. Based on the first power level of the received unsolicited signals, the monitoring aircraft interrogates the target aircraft with a first interrogation signal.

Abstract: In an aircraft which has a tracking system, the aircraft interrogates all target aircraft in the vicinity of the aircraft in order to determine potentially dangerous situations. The interrogation has a predetermined interrogation sequence which includes interrogation pulses and suppression pulses. The target aircraft respond to the interrogation with predetermined parameter information, the target aircraft sometimes responding to the suppression pulses of the interrogation resulting in an indication of false tracks to the monitoring aircraft. A method is implemented which reduces the false tracks resulting from replies to the suppression pulses. The method comprises the steps of forming tracks on responses to the interrogations wherein the responses meet a first set of predetermined criteria. The formed tracks are then identified as suppression pulse tracks or non-suppression pulse tracks in accordance with a second set of predetermined criteria.

Abstract: Data bases of a first and second input output processor (IOP), which are primary and secondary slave IOPs, respectively, are synchronized, and communications by a master controller is made only to the first IOP. Each IOP is executing the same tasks utilizing their own clocking systems. A method for periodically verifying that the first and second data base remain synchronized comprises the steps of sending a sync-verify type message to the first IOP. The second IOP eavesdrops on the communications, and when the second IOP recognizes that the message is addressed to the corresponding primary slave IOP, accepts the message. Upon detecting the message is of the sync-verify type by each IOP, operations by each IOP are suspended. A number is generated by each IOP of its own data base, the number being indicative of the contents of the information stored in the data base.

Abstract: Data bases of a first and second input output processor (IOP), which are primary and secondary slave IOPs, respectively, are synchronized, and communications by a master controller is made only to the first IOP. Each IOP is executing the same tasks utilizing their own clocking systems. A method for guaranteeing that the first and second data base remain synchronized comprises the steps of communicating a message to the first IOP to update the first data base. The second IOP eavesdrops on the communications, and when the second IOP recognizes that the message is to the corresponding primary slave IOP and that the first IOP has successfully received the message, accepts the message. The first IOP and the second IOP execute the received message. The master controller issues a status request type message to the first IOP, and then issues a status request type message to the second IOP.

Abstract: An input data stream (a manchester encoded data stream which includes a clock signal component and has some jitter) is inputted to a clock extractor for extracting the clock signal component, the clock signal component having missing clock pulses. A delay line oscillator provides the missing clock pulses and outputs a recovered clock signal. The recovered clock signal has a first delay time as a result of inherent delays in the delay line oscillator and the clock extractor. A latch element receives the recovered clock signal and the input data stream, the input data stream being delayed a second delay time, the first delay time and the second delay time being essentially the same. The latch element reclocks the input data stream thereby removing a maximum amount of jitter and removes any distortion of the input data stream.

Abstract: In a Traffic Alert and Collision Avoidance System on an aircraft having a plurality of antennas, an optimal bearing value is obtained for each target aircraft by generating a target data block for each response to an interrogation, each target data block including a measured bearing value and an associated priority code. A priority code is assigned based on the antenna receiving the information, and the number of valid bearing measurements used to determine a measured bearing value for the reply. If more than one target data block is obtained in a surveillance period, one target data block is retained based on predetermined criteria. The measured bearing value of all the target data blocks having the same, highest priority code are selected or combined, the result being saved in the target data block. The priority codes are then used to select the proper reply bearing measurement, the bearing track update filtering parameters, and to aid in the reply qualification for bearing track initialization.

Abstract: A system has at least one output device, the output device having a first set of output terminals connected to a corresponding field device. Each output device has a corresponding redundant output device having a corresponding first set of output terminals connected to the same corresponding field device as the corresponding output device. The output device and the redundant output device each have a second set of output terminals corresponding to the first set of output terminals, the second set of output terminals being connected to an apparatus for controlling the information outputted from the first set of output terminals. The apparatus comprises a plurality of switching elements, having a set of first and second contact points. Each of the second set of output terminals of the output device being connected to a corresponding first contact point, and the second set of output terminals of the redundant output device being connected to the corresponding second contact point.

Abstract: A process control system which is controlling a continuous process produces an output product having a first grade. The process control system performs quality checks at predetermined times on the output product for verifying predetermined parameters of the output product of the first grade are within predetermined limits. A method for dynamically monitoring the continuous process (without shutting down the process) when the grade of the output product is changed to a second grade having second predetermined limits, comprises the steps of initiating new setpoints for the continuous process to produce an output product having the second grade. The predetermined parameters of the output product is verified by the process control system to be within second predetermined limits of the second grade. When the predetermined parameters of the output product fall outside the second predetermined limits, an alarm is indicated, and the output product divert to a bypass path.

Abstract: An apparatus of a process control system for controlling a process variable of a process includes an adaptive controller tuned to the process. The process variable output signal of the process is coupled to a difference device and also coupled to the adaptive controller, thereby permitting the adaptive controller to monitor the process variable signal independently of an error signal outputted from the difference device. Any changes detected in the process variable signal without a corresponding change in the setpoint signal inputted to the difference device initiates an adjustment in the tuning parameters of the adaptive controller thereby providing continual, optimal, control of the process.

Abstract: A primary (first) and secondary (second) slave (IOP) collect input pulses from a field device, each independently maintaining an interim total number of pulses. A master controller executes a method for maintaining the total number of pulses for the entire process by requesting the interim total number of pulses, a process variable, and a flag from the first IOP by the controller. If the flag indicates no anomaly in the interim total number of pulses or the process variable, the master controller determines a new interim total number of pulse and the process variable since the previous request. The new interim total number of pulses and the process variable is saved in a temporary holding area, such that upon a failover of the first IOP, differences in the interim total number of pulses transmitted by the second IOP can be handled without causing an error in the total number of pulses for the entire process being maintained by the master controller.

Abstract: A plant control system includes a plant control network for performing the overall supervision of a process being controlled. The plant control network has at least one external bus for operatively connecting a corresponding interface apparatus to the plant control network. Further, each interface apparatus interfaces with at least one predetermined field device, each field device being a type having a corresponding predetermined signal type. The interface apparatus comprises a controller for controlling the input/output (I/O) of the interface apparatus. At least one I/O module, connected to the controller, preprocesses information signals to and from the predetermined field device connected to the I/O module. The preprocessing is a translation between the signal type of the field device and signals compatible with the controller.

Abstract: Data bases of a first and second input output processor (IOP), which are primary and secondary slave IOPs, respectively, are sychronized, and communications by a master controller is made only to the first IOP. Each IOP is executing the same tasks utilizing their own clocking systems. A method for maintaining synchronization between the first and second IOP comprises the steps of transmitting a message addressed to the first IOP by the master controller. The first IOP receives the message for subsequent execution. Receipt of the message is acknowledged by a transmission back to the master controller the acknowledge message including a message number. The second IOP eavesdrops on the transmissions between the master controller and any of the IOPs on the network. Upon recognizing that the message is addressed to the corresponding first IOP and that the message is of a predetermined type, the second IOP receives the message for subsequent execution.

Abstract: The apparatus for sensing pressure comprises a header, having at least one input port for receiving a substance under pressure. A substrate, having a wafer-like shape with a relatively large surface area in comparision to its thickness, includes at least one internal passage to couple the substance under pressure. A pressure sensing element is mounted onto the surface of the substrate over an exit port of the internal passage coupling the substance under pressure. The substrate is bonded to a surface of the header at extreme locations from a location in which the pressure sensing element is mounted. Thus isolation is provided for the pressure sensing element from unwanted stresses induced in the substrate.