Abstract: A broadcast capable file system is disclosed. In a method, a server may receive a file request from a requesting client and prepare a broadcast response to the file request. The broadcast response may be directed to a group of clients of which the requesting client is a member. In another method, at least one of the clients of the group of clients may submit a file request to the server. Each of the clients of the group may receive a broadcast response to the file request. The broadcast capable file system may be implemented between a server computing device and multiple client computing devices. The server computing device and multiple client computing devices may be included in a network testing system.

Abstract: A field current control circuit for an alternating current generator includes a first voltage source and a time lag reduction circuit, which further includes a generator field that is in selective electrical communication with an energy storage component that is in electrical communication with a time lag reduction voltage source. The time lag reduction circuit may include an electronic controller and be a part of an electric drive machine that receives an operator acceleration command and thereby controls the electrical communication between the energy storage component and the generator field of the time lag reduction circuit. When the energy storage component and generator field are in electrical communication, the current passing through the generator field increases from a starting current to a target current with a reduced time lag compared to predecessor generators.

Abstract: A field current control circuit for an alternating current generator includes a first voltage source and a time lag reduction circuit, which further includes a generator field that is in selective electrical communication with an energy storage component that is in electrical communication with a time lag reduction voltage source. The time lag reduction circuit may include an electronic controller and be a part of an electric drive machine that receives an operator acceleration command and thereby controls the electrical communication between the energy storage component and the generator field of the time lag reduction circuit. When the energy storage component and generator field are in electrical communication, the current passing through the generator field increases from a starting current to a target current with a reduced time lag compared to predecessor generators.

Abstract: Systems and methods are disclosed for detecting a faulty ground strap connection for a machine hosting a high voltage system. In one embodiment, a fault detection and compensation system includes a ground strap, a DC power supply electrically referenced to a machine frame, a leakage detection switch connected to the machine frame, a current source controlled by the leakage detection switch, and a voltage measuring device that measures an offset voltage. The fault detection and compensation system further includes a leakage detection and compensation controller that compensates for the unbalanced fault condition by controlling the leakage detection switch and the current source, and determines whether the ground strap is properly connected to the machine frame.

Abstract: Systems and methods are disclosed for compensating electrical leakage and detecting balanced electrical leakage for a machine hosting an HV system. In one embodiment, a fault detection and compensation system includes a DC power supply electrically referenced to a machine frame, a leakage correction switch connected to the machine frame, a current source controlled by the leakage correction switch, and a voltage measuring device that measures an offset voltage reflecting whether the HV system is in an unbalanced fault condition. The fault detection and compensation system further includes a leakage detection and compensation controller that compensates for the unbalanced fault condition by controlling the leakage correction switch and the current source.

Abstract: Methods and apparatus for testing performance of an system under test are disclosed. The system under test is loaded with simulated traffic which may be generated from a single test port. The performance of the system under test under load may be tested.

Abstract: Systems and methods are disclosed for detecting a faulty ground strap connection for a machine hosting a high voltage system. In one embodiment, a fault detection and compensation system includes a ground strap, a DC power supply electrically referenced to a machine frame, a leakage detection switch connected to the machine frame, a current source controlled by the leakage detection switch, and a voltage measuring device that measures an offset voltage. The fault detection and compensation system further includes a leakage detection and compensation controller that compensates for the unbalanced fault condition by controlling the leakage detection switch and the current source, and determines whether the ground strap is properly connected to the machine frame.

Abstract: Systems, methods and devices for virtual network addresses. A method comprises processing a request from a requestor to create a plurality of software network devices having a corresponding plurality of media access control (MAC) addresses. The MAC addresses may be allocated to a network interface circuit. The MAC addresses and the software network devices may be provided to the requestor. Incoming data units may be received from a network via a driver and a demultiplexor. Outgoing data units may be sent on to the network via a driver.

Abstract: An apparatus and method for transferring a signal from a first bus circuit to a second bus circuit. The apparatus and method includes a first constant current circuit connected to the first bus circuit, a first capacitor connected between the first bus circuit and the first constant current circuit, a second constant current circuit connected to the second bus circuit, a second capacitor connected between the second bus circuit and the second constant current circuit, and an opto-coupler connected between the first and second constant current circuits and providing signal transfer control from the first capacitor to the second capacitor.

Abstract: Systems and methods are disclosed for compensating electrical leakage and detecting balanced electrical leakage for a machine hosting an HV system. In one embodiment, a fault detection and compensation system includes a DC power supply electrically referenced to a machine frame, a leakage correction switch connected to the machine frame, a current source controlled by the leakage correction switch, and a voltage measuring device that measures an offset voltage reflecting whether the HV system is in an unbalanced fault condition. The fault detection and compensation system further includes a leakage detection and compensation controller that compensates for the unbalanced fault condition by controlling the leakage correction switch and the current source.

Abstract: An apparatus and method for transferring a signal from a first bus circuit to a second bus circuit. The apparatus and method includes a first constant current circuit connected to the first bus circuit, a first capacitor connected between the first bus circuit and the first constant current circuit, a second constant current circuit connected to the second bus circuit, a second capacitor connected between the second bus circuit and the second constant current circuit, and an opto-coupler connected between the first and second constant current circuits and providing signal transfer control from the first capacitor to the second capacitor.

Abstract: A method is provided for detecting electrical leakage between a power supply and a frame of a vehicle or machine. The disclosed method includes coupling a first capacitor between a frame and a first terminal of a power supply for a predetermined period of time. The current flowing between the frame and the first capacitor is limited to a predetermined current limit. It is determined whether the voltage across the first capacitor exceeds a threshold voltage. A first output signal is provided when the voltage across the capacitor exceeds the threshold voltage.

Abstract: A method is provided for detecting electrical leakage between a power supply and a frame of a vehicle or machine. The disclosed method includes coupling a first capacitor between a frame and a first terminal of a power supply for a predetermined period of time. The current flowing between the frame and the first capacitor is limited to a predetermined current limit. It is determined whether the voltage across the first capacitor exceeds a threshold voltage. A first output signal is provided when the voltage across the capacitor exceeds the threshold voltage.

Abstract: A resettable circuit breaker includes a current monitoring and interrupting circuit including an electrically conductive line carrying a current. A sensor outputs a voltage level indicative of the magnitude of the current. A comparator compares the voltage level to a reference potential and generates a circuit indicator signal. A logic-based current interrupter controls the current in the line in response to the circuit indicator signal.

Abstract: An apparatus and method for measuring a characteristic, such as speed, of a machine. A variable reluctance sensor (VRS) is coupled to a resistive element, which filters a portion of a basic output signal generated by the VRS having a frequency above a prescribed threshold level, thus removing high-frequency noise from the basic output signal. An amplifier amplifies the filtered output signal. The filtered, amplified output signal has an increased signal-to-noise ratio such that the machine characteristic, i.e. speed, can be more accurately measured during a slow speed operation. A controller generates a control signal received by a switching device to decouple the resistive element when machine speed exceeds a prescribed threshold level. Then, the basic output signal is used to measure the characteristic of the machine during normal machine operation.

Abstract: An apparatus and method for measuring a characteristic of a machine. A variable reluctance sensor (VRS) is coupled to the machine. A first switching device and capacitor, coupled in parallel with the VRS, boosts a variable amplitude of a basic output signal generated by the VRS to increase the signal-to-noise ratio. A control input of the first switching device receives signals, and a modified output signal is generated by the first switching device, having a variable amplitude that is substantially higher than the variable amplitude of the VRS. The modified output signal has an increased signal-to-noise ratio such that machine speed can be more accurately measured during a start-up phase.

Abstract: Systems, methods and devices for virtual network addresses. A method comprises processing a request from a requestor to create a plurality of software network devices having a corresponding plurality of media access control (MAC) addresses. The MAC addresses may be allocated to a network interface circuit. The MAC addresses and the software network devices may be provided to the requestor. Incoming data units may be received from a network via a driver and a demultiplexor. Outgoing data units may be sent on to the network via a driver.

Abstract: A power circuit includes a first electrically-energizable contactor configured to receive a first power input of 110-120 volts of alternating current (VAC), and a second electrically-energizable contactor configured to receive a second power input of 220-240 VAC. The first and second contactors are arranged such that when one of the first and second contactors is energized by the corresponding power input, the energized one of the first and second contactors prevents the other one of the first and second contactors from being energized.

Abstract: An apparatus and method for measuring a characteristic, such as speed, of a machine. A variable reluctance sensor (VRS) is coupled to a resistive element, which filters a portion of a basic output signal generated by the VRS having a frequency above a prescribed threshold level, thus removing high-frequency noise from the basic output signal. An amplifier amplifies the filtered output signal. The filtered, amplified output signal has an increased signal-to-noise ratio such that the machine characteristic, i.e. speed, can be more accurately measured during a slow speed operation. A controller generates a control signal received by a switching device to decouple the resistive element when machine speed exceeds a prescribed threshold level. Then, the basic output signal is used to measure the characteristic of the machine during normal machine operation.

Abstract: An apparatus and method for measuring a characteristic of a machine. A variable reluctance sensor (VRS) is coupled to the machine. A first switching device and capacitor, coupled in parallel with the VRS, boosts a variable amplitude of a basic output signal generated by the VRS to increase the signal-to-noise ratio. A control input of the first switching device receives signals, and a modified output signal is generated by the first switching device, having a variable amplitude that is substantially higher than the variable amplitude of the VRS. The modified output signal has an increased signal-to-noise ratio such that machine speed can be more accurately measured during a start-up phase.