摘要:
An electronic energy meter is described. The meter includes, in one form, voltage and current sensors having their outputs coupled to an analog to digital converter. The digital signals output by the converter are supplied to a digital signal processor (DSP) which outputs digitized metering quantities to a microcomputer. Using the metering quantities supplied by the DSP, the microcomputer performs additional metering calculations and functions. In one aspect, the present invention is directed to a method for determining whether an option board is being used and, if so, controlling meter operations in accordance with the coupled option board. In another aspect, the present invention is directed to a high function option board which, when enabled, operates as a master and the meter microcomputer automatically switches from its normal master mode to slave mode. In yet another aspect, the present invention is directed to converting the functionality of the electronic electricity meter from a first mode of operation to a second mode of operation. In still another aspect, the present invention is directed to a structure for avoiding, or minimizing, the loss of billing data when converting, or upgrading (or downgrading), meter operations.
摘要:
An electricity meter having a protected enabling scheme for activating meter options and upgrades is presented. The meter has a unique serial number, which includes bit-flags indicating which options have already been enabled, stored in the non-volatile RAM. Each option which is not enabled must be requested and a password verified before it can be utilized. At least one password is stored in a read protected location in the non-volatile RAM. The meter is in communication with a computer, e.g., a desktop or laptop type of computer. The password is generated by processing a secret software key and the unique serial number of the meter with an authentication algorithm. The computer is loaded with an upgrade software program, which includes the authentication algorithm. A hardware key which stores a secret software key is attached to a parallel port of the computer. The upgrade software program reads the serial number from the non-volatile RAM in the meter and reads the secret software key from the hardware key, then processes the read secret software key and the read unique serial number of the meter with the stored authentication algorithm to generate at least one password. The password along with an upgrade command are presented to the meter where they are compared to the read-protected password in the meter, and, if there is a match, then the upgrade command initiates codes in the meter to implement one or more stored options or upgrades.
摘要:
Methods, systems, and apparatus for controlling a turbine clearance in an aircraft engine are provided. A method includes activating a turbine clearance control based on a flight phase of an aircraft using the aircraft engine, and adjusting the turbine clearance based on a preselected turbine clearance value.
摘要:
Systems are provided for efficiently managing the effects of a change to a transportation system's state. One example system comprises a plurality of distributed data input and data output terminals, the distributed data input terminal configured to automatically generate data related to a first aspect of transportation system operation, at least one of a distributed database and a synchronized database configured to store data, a plurality of distributed computational engines configured to receive data from at least one database, and based on the data received, automatically manage operations of a second, different aspect of the transportation system operations, and a communications network linking the data input terminals, the data output terminals, the databases, and the computational engines, wherein the change to the transportation system's state is initiated by the data generated at the distributed input terminals.
摘要:
The present invention provides a novel Geometric Harmonic Modulation (GHM) method. The GHM method functions in two modes, a preamble mode and a traffic mode. During the preamble mode, n+1 frequencies are each offset by a predetermined phase in a transmit unit and passed through a channel to a receive unit. The set of phases is used as the spreading code in the transmit unit, and also acts as an `address` of intended receive units. The receive unit monitors preamble signals to determine the phases. When it recognizes a set of phases, or `address`, which pertains to itself, the receive unit stores the phases and uses these phases to despread and decode the appended message. After the preamble mode is finished, the GHM modulator enters the traffic mode and requests the message to be transmitted from the message source. A traffic carrier waveform is created by multiplying tones, each having its specific phase. An analog or binary message is encoded by modulating the traffic carder waveform. The receive unit detects a preamble carrier and recovers the particular preamble phases to be used as the despreading `key`. The receive unit then employs the phases in despreading the received signal to recover the transmitted binary message.
摘要:
A signal processor includes a phase looked loop for estimating a largest sine wave component phase and frequency element of an incoming analog signal to provide a component signal and a delta-adjusted subtraction loop for removing a largest sine wave component of the incoming signal. The subtraction loop includes a gain adapter for monitoring an output signal and calculating a gain for minimizing the magnitude of the output signal, a multiplier for multiplying the gain by the component signal to provide a multiplied signal, and a subtractor for subtracting the multiplied signal from the incoming analog signal and supplying the output signal to the gain adapter. The gain adapter in one embodiment includes an algorithm capable of repeating the following sequence during a predetermined period of time: adapting a gain by adding a voltage limit; calculating a present maximum absolute value of a subtracted signal (the output signal) over a measurement cycle; comparing the present maximum absolute value with a previous maximum absolute value and, if the present maximum absolute value is greater, changing the sign of the voltage limit, and adapting the gain by adding the voltage limit; multiplying the voltage limit by a fraction having a value less than one; and changing the previous maximum absolute value to the present maximum absolute value.
摘要:
Data words are transmitted over a radio channel with a novel modulation scheme which transmits data in parallel. An entire data word is modulated by separating a carrier frequency band into a number of discrete `tones`. Tone T.sub.1 is set to a zero phase shift in order to provide timing in synchronization of the signal. The remaining tones are phase shifted according to a predetermined convention, thereby encoding the bits of the data word. The phase shifts for all tones comprises a spectrum which is transmitted to a receiver simultaneously. A receiver monitors tone T.sub.1 for zero phase shifts to provide synchronization of the signal. The remaining tones are analyzed for their phase shift to provide bits which are assembled into a transmitted data word. Since the bits are transmitted in parallel as the data word, as opposed to conventional modulation schemes, the throughput is increased.
摘要:
A highly fault tolerant system for datagram communication of information in the form of a message packet employs a distributed network of transmitter/receivers `transceivers`, which interact with `bridge transceivers` which are transceivers connected to a wired network, and wired nodes each having a unique identification ("ID") number. An initiating unit, which may be a transceiver, bridge transceiver or wired node, creates a message packet having an ID of an intended destination unit. If initiated from a transceiver, the message packet finds its way to a wired network by broadcasting the message packet to local transceivers. The transceivers determine valid message packets which have not expired, not been received before and were transmitted without errors. If the message packet is valid and the transceiver ID does not match its internal ID, the transceiver broadcasts the valid message packet to other local transceivers. The transceivers which receive the message packet repeat the process. The message then finds its way to a bridge transceiver connected to a wired network. A `NODE LOC` is embedded in the message packet identifying a closest wired node. The message is routed through the wired network to the wired node and then transmitted as described above to a destination unit by radio signals.
摘要:
A countermeasure to a partial-band follower jammer for frequency hopping spread spectrum communication systems employs an M-ary orthogonal frequency shift keyed (FSK) signaling system having q frequency channels available for hopping. During each signaling interval, the transmitter and receiver operate in either a conventional or unconventional mode. The conventional mode is selected by the transmitter and the receiver with a pseudorandom probability p.sub.c. In this mode, the transmitter transmits one of r tones within the corresponding hop (i.e., within one of q channels), and log.sub.2 r information bits are conveyed, while the receiver comprises a dehopper followed by noncoherent matched filters. The unconventional mode is selected with probability 1-p.sub.c. In this mode, the transmitter randomly chooses one of the r tones and transmits it in one of r channels within each hop, where the r channels are selected pseudorandomly. In the unconventional mode, log.sub.2 r information bits are transmitted and the receiver comprises a bank of r radiometers.
摘要:
A method for operating a train having at least one locomotive vehicle, the method including controlling operation of the train via a first crew member located on-board the locomotive unit, providing information that may be required for operation of the train to a second crew member located remote from the first crew member, and using the information to enable the second crew member to assist the first crew member in the controlling of the train.