Abstract: An apparatus for determining if an elevator car is level with respect to a landing comprises: a first magnet disposed proximate to the landing; a second magnet disposed proximate to the landing; a sensor for providing a level signal in response to detecting a minimum flux region formed by the first and second magnets; and a processor for determining if the elevator is level with respect to the landing in response to the level signal. Each magnet has a first and second magnetic pole. The first and second magnets are adjacently aligned such that the first magnetic pole of the first magnet is adjacent to the first magnetic pole of the second magnet, and the second magnetic pole of the first magnet is adjacent to the second magnetic pole of the second magnet.

Abstract: An active noise control system is provided with a plurality of error sensor arrays 50,77 which provide signals on lines 64-74,90-100 to beam forming and beam steering logic 76 which cause the arrays 50,77 to exhibit acoustic response profiles 104,106, respectively. The profiles 104,106 intersect in a predefined region 116 to be quieted. The logic 76 provides signals on lines 118, one for each region to be quieted, to active noise control (ANC) logic 20 which also receives inputs from feedforward sensing microphones 10 and provides output signals to acoustic speakers 24 which generate anti-noise 26 to cancel the noise in the quiet region 116. The quiet region 116 may be selectively positioned to any region in the room by steering the beams 104,108. Alternatively, the system may have a plurality of distributed sensors which, when taken together, have an overall maximum (main lobe) acoustic response at a predetermined selectable quiet region.

Abstract: An elevator position determination system for determining the position of an elevator car disposed in the elevator hoistway includes a transceiver disposed on the elevator car for generating a query signal and a transponder disposed in the elevator hoistway for providing an identification signal in response to the query signal, wherein, the elevator position determination system determines the elevator car position in response to the identification signal.

Abstract: The pseudorandom process iteratively applies a selected CRC encryption process on the information to be encrypted. The encryption process is selected by testing one of the digits comprising the number to be encrypted. A first encryption process is used if the tested digit is a 1; a second encryption process is used if the tested digit is a 0. The process is repeated a plurality of times, e.g. once for each digit in the number to be encrypted, resulting in a highly encrypted value that is not easily reverse engineered by chosen or known plaintext attack.

Abstract: The pseudorandom process iteratively applies a selected CRC encryption process on the information to be encrypted. The encryption process is selected by testing one of the digits comprising the number to be encrypted. A first encryption process is used if the tested digit is a 1; a second encryption process is used if the tested digit is a 0. The process is repeated a plurality of times, e.g. once for each digit in the number to be encrypted, resulting in a highly encrypted value that is not easily reverse engineered by chosen or known plaintext attack.

Abstract: The digital information is encrypted by first performing a preselected number of CRC iterations or partial convolutions by multiplication with a mask in the Galois Field. Before the CRC operation is completed, the intermediate resultant is subjected to an Integer Ring operation, such as addition, which injects a nonlinearity over the Galois Field due to possible arithmetic carry operations. After the Integer Ring operation, the Galois Field CRC process is continued to completion. The result is an encrypted value which is not readily decrypted by Galois Field techniques.

Abstract: An automobile door lock receiver module (30) and a plurality of keychain fob transmitter units (16) contain identification numbers, secret initial values, and secret feedback masks so as to authenticate encrypted messages from any of the assigned fobs, indicative of commands registered by closing switches on the fob. Each fob is synchronized with the receiving module by means of a truly random number concatenated with a secret initial value and encrypted, through a linear feedback shift register or other operations. A second secret initial value is encrypted and command bits are exclusive ORed into the low order bit positions; the two encrypted numbers are concatenated and encrypted to form a key word which is transmitted with the fob ID. Synchronization includes decrypting to recover the truly random number and the secret initial value concatenated therewith; the truly random number is compared with previously received random numbers in order to avoid copying of recently transmitted synchronization commands.

Abstract: An automobile door lock receiver module (30) and a plurality of keychain fob transmitter units (16) contain identification numbers, secret initial values, and secret feedback masks so as to authenticate encrypted messages from any of the assigned fobs, indicative of commands registered by closing switches on the fob. Each fob is synchronized with the receiving module by means of a truly random number concatenated with a secret initial value and encrypted, through a linear feedback shift register or other operations. A second secret initial value is encrypted and command bits are exclusive ORed into the low order bit positions; the two encrypted numbers are concatenated and encrypted to form a key word which is transmitted with the fob ID. Synchronization includes decrypting to recover the truly random number and the secret initial value concatenated therewith; the truly random number is compared with previously received random numbers in order to avoid copying of recently transmitted synchronization commands.

Abstract: A remote operating system for remote-controlled operation of a device provides secure communication of encoded messages between a transmitter (100) and receiver (150) of the system, and provides automatic re-synchronization of the transmitter and receiver without revealing a loss of synchronization to the operator. A pseudo random binary number (PRBN) generator (105) in the transmitter (100) produces a sequence of identification numbers. Each time the transmitter (100) is activated, the identification number contained in the transmitted encoded message is selected as the next number in the sequence of identification numbers. A PRBN generator (170) in the receiver (150) produces a sequence of reference numbers that is identical to the sequence of identification numbers. The receiver responds to a command code portion of the transmitted encoded message for operation the device when there is identity between the reference number and the identification number.

Abstract: A task communicator for each node in a multiple node processing system having a data memory storing data received from a voter interface which is used for the execution of tasks by an associated applications processor, a next task register storing the identification code of the next task to be executed by the applications processor received from a scheduler through a scheduler interface. An input handler passes the identification code of the next task and the data required for the execution of that task to an input FIFO register interfacing the applications processor. An output FIFO register temporarily stores the data generated by the applications processor and an output handler generates inter-node messages containing data stored in the output FIFO and passes these inter-node messages to a transmitter through a transmitter interface for transmission to all of the other nodes in the processing system.

Abstract: A voter subsystem for a multiple node fault tolerant system having an upper medial value sorter for sorting a plurality of received values to generate an upper medial value and a lower medial value sorter for sorting the same plurality of received values to generate a lower medial value. An averaging circuit adds the upper and lower medial values then divides by two to generate a voted value. A deviance checker checks each of the plurality of received values against the voted value to generate a deviance error for each received value which differed from the voted value by a predetermied amount. A loader loads the plurality of received values into the upper and lower medial value sorters and the deviance checker bit-by-bit, starting from the most significant bit positions through the least significant bit positions. The upper and lower medial value sorters and deviance checker process the received values on-the-fly in the order they are received.

Abstract: A fault tolerator for an operations controller of a multiple node fault tolerant processing system having a data memory for storing the content of all received error free messages, an error file for storing the content of all received inner node error reports, an error handler for generating a base penalty count for each node based on the content of the errors recorded in the error file and for excluding each node from the operation of the multiple node processing system whose base penalty count exceeds an exclusion threshold. The fault tolerator also includes a synchronizer interface for passing the selected fields of the received messages to a synchronizer, a scheduler interface for passing selected information to a scheduler, and a message interface which stores the error free messages in the data memory and passes the selected fields of the messages to the synchronizer.

Abstract: An operations controller for a multiple node fault tolerant processing system having a transmitter for transmitting inter-node messages, a plurality of receivers, each receiving inter-node messages from only one of the nodes and a message checker for checking each received message for physical and logical errors. A fault tolerator assembles all of the errors detected and decides which nodes are faulty based on the number and severity of the detected errors. A voter generates a voted value for each value which is received from the other nodes which is stored in a data memory by a task communicator. A scheduler selects the tasks to be executed by an applications processor which is passed to the task communicator. The task communicator passes the selected task and the data required for the execution of that task to the applications processor and transmits the data resulting from that task to all of the nodes in the system.

Abstract: A synchronizer for each node in a multiple node processing system having a message interface for receiving sync and pre-sync time-dependent message, counter means for generating a local time, a time stamp memory having an entry for each node in the multiple node processing system, a time stamper responsive to receiving a time-dependent message from a node for storing the local time in the entry of said time stamp memory for that node to generate a time stamp.

Abstract: A task scheduler for a fault tolerant multiple node processing system having a task activity list storing a set of application tasks, a priority scan list storing a selected portion of the set of application tasks, a completion status list also storing the same selected portion of the set of application tasks. A wake-up sequencer transfers the application tasks from the task activity list to the priority scan list, and a priority scanner transfers the application tasks ready for execution from the priority scan list to a selection queue. A next task selector selects the next application task that its node will execute, and a task started register stores the identity of the application tasks completed by the other nodes. A task interactive consistency (TIC) handler updates the status of the application tasks stored in the task activity list, the priority scan list, and the completion status list in response to messages received from the other nodes identifying which nodes completed tasks.

Abstract: An automobile door lock receiver module (30) and a plurality of keychain fob transmitter units (16) contain identification numbers, secret initial values, and secret feedback masks so as to authenticate encrypted messages from any of the assigned fobs, indicative of commands registered by closing switches on the fob. Each fob is synchronized with the receiving module by means of a truly random number concatenated with a secret initial value and encrypted, through a linear feedback shift register or other operations. A second secret initial value is encrypted and command bits are exclusive ORed into the low order bit positions; the two encrypted numbers are concatenated and encrypted to form a key word which is transmitted with the fob ID. Synchronization includes decrypting to recover the truly random number and the secret initial value concatenated therewith; the truly random number is compared with previously received random numbers in order to avoid copying of recently transmitted synchronization commands.