Abstract: The detent signals produced by the rotation of a selector switch knob are counted and stored in a first register, the contents of the register including a sign position designating the direction of rotation of the selector switch knob. The contents of the first register are periodically combined with the contents of a second register, permitting an operator to insert any desired numerical value in the second register. In order to expedite the insertion of a desired numerical value in the second register, when the rate of detent signal generation exceeds a preselected value, a numerical value, greater than the rate of detent signal generation, is combined with the contents of the second registr. Two algorithms are disclosed that permit the numerical value added to the second register to increase at a rate greater than the increase in detent signal generation. In this manner, a large numerical value can be entered in the second register without excessive rotation of the selector switch knob.

Abstract: In a liquid crystal display, the optical transmission of the liquid crystal medium as a function of applied electric field varies with temperature. In order to ensure that the temperature of the liquid crystal medium can provide a practical response time, a heating element, along with a sensor element and a thermostat, establishes the temperature of the liquid crystal display in an appropriate range. The output signal of the sensor element is digitized and is used as a first portion of a memory unit address. A second portion of the memory unit address is provided by digitized command signals either from an operator or from the processing apparatus controlling the image of liquid crystal display. The logic signals stored at the location determined by the first and second address portions identify an electric field (applied voltage) that provides compensation for temperature and compensation for non-linear characteristics of the liquid crystal medium.

Abstract: Apparatus and an associated method are described for an aircraft for providing an auto-changeover procedure from a calibrated airspeed control parameter to a Mach number control parameter when the aircraft is ascending; and, from a Mach number control parameter to a calibrated airspeed parameter when the aircraft is descending. The auto-changeover procedure is responsive to application of preselected calibrated airspeed and Mach number parameters. The data processing unit of the aircraft provides a continually updated prediction of the target parameter that would result should the aircraft execute the auto-changeover under the currently existing conditions. When the predicted value and the preselected value are equal, the changeover procedure is invoked, reducing the transients resulting from overshoot of the target parameter value. Provision is made for the circumstance wherein the changeover is determined by an altitude rather than a target parameter.

Abstract: A dialogue system uses a three wire bus connecting a central station with a plurality of substations with two of the wires carrying an AC supply voltage and a third one of the wires carrying data by means of a closed loop of the AC carrying wires and the third wire. The central station uses a series connection of a data transmitter and a data receiver with the third data wire and each substation includes a data receiver in series with the data wire and a data transmitter between the data wire and both AC wires.

Abstract: In a digital data transmission system for transmitting a serial digital data stream between a first unit and a second unit connected to a first and second bus, respectively, a first apparatus interfaces the first bus to a transmission medium and a second apparatus interface the second bus to the transmission medium. The first and second unit and the first and second apparatus each have their own clock circuit. The first and second apparatus each comprise an encoder which outputs the serial digital data stream onto the transmission medium corresponding to serial data received from the first bus during a transmission period of the first bus. The encoder outputs the serial digital data stream onto the transmission medium in a predetermined format during a quiescent period of the first bus. A phase relationship of the serial data and the serial digital data stream outputted at the start of transmission between the quiescent period and the transmission period is established in a single bit time.

Abstract: A process control system has a network which includes a plurality of modules, each module performing a predetermined function. The modules include at least one history module, and at least one application module, the modules being linked via a medium such that each module can communicate with every other module of the network. The network interfaces with a control subsystem which interfaces with control elements of a plant process, the control elements having associated therewith process data. The process data includes data values and event data; the total data includes process data, data calculated from the process data, off-line data, and external data, the total data being stored in a storage device of the history module. A method for maintaining the total data comprises the steps of queuing messages requesting selected portions of the total data to be stored in said storage device.

Abstract: The apparatus controls the positioning of a device in response to a commanded input signal, and comprises an element for moving the device in response to an error signal. A sensor component determines the actual position of the device, the sensor component outputting a primary signal and a derivative signal corresponding to the actual position and velocity of the device, respectively. A complementary filter system filters the primary signal and the derivative signal to generate a derived position signal, the derived position signal being combined with the commanded input signal thereby generating the error signal. The filtering results in effectively increasing the resolution of the sensor component thereby reducing the limit cycle caused by quantization of the sensor component.

Abstract: The fiber optic network of the present invention is within a structure having a plurality of bulkheads. The network comprises a plurality of terminal groups, each terminal group having at least one terminal. The network includes a reflective star coupler having m ports, m corresponding to the number of terminal groups. The terminal groups (having more than one terminal) include a 1.times.n transmissive coupler having 1 input port and n output ports, the input port being connected to the reflective star coupler via one of the m fiber optic cables, such that each bulkhead has a single fiber optic cable passing through the bulkhead.

Abstract: A communication system which includes a modem and a plurality of controllers has each controller connected to the modem by an interface apparatus, each controller and the modem complying with a predetermined protocol. The interface apparatus comprises a bus which provides a medium to transfer signals between the controllers and the modem. A first interface unit, which interfaces the modem to the bus, implements, a modem-associated multi-state state machine and responds to signals on the bus maintaining the predetermined protocol between the modem and the first interface unit. A plurality of second interface units interface a corresponding controller to the bus. Each second interface unit implements a controller-associated multi-state state machine which responds to signals on the bus and further responds to signals from the corresponding controller, each second interface unit maintaining the predetermined protocol between the second interface unit and the corresponding controller.

Abstract: A communication system which includes a modem and a plurality of controllers has each controller connected to the modem by an interface apparatus, each controller and the modem complying with a predetermined protocol. The interface apparatus comprises a first component, a bus, which provides a medium to transfer signals between the controllers and the modem. A second component provides an arbitration path between said controllers. A first interface unit, which interfaces the modem to the bus, implements a modem-associated multi-state state machine and responds to signals on the bus maintaining the predetermined protocol between the modem and the first interface unit. A plurality of second interface units interface a corresponding controller to the bus.

Abstract: The data processing system, has at least one memory unit operatively connected to a memory bus, and further has an input/output (I/O) bus controller for interfacing at least one peripheral device to the data processing system. The data processing system comprises a first bus which provides a first transmission medium between the peripheral device and the memory bus. A second bus, provides a second transmission medium between a CPU and the memory bus. A logic element, interposed between the first and second bus, and the memory bus, interfaces the first and second bus to the memory bus in response to request signals from the first and second bus.

Abstract: A process control system includes a processor which outputs command signals to a plurality of field devices via an interface unit. The interface unit comprises a primary output unit for outputting a first set of the command signals to the field devices in response to a first control signal. The first set of command signals are command signals for normal operation of the process control system. A secondary output unit outputs a second set of the command signals to the field devices in response to a second control signal. The second set of command signals are command signals for a failure mode of operation of the process control system. The second set of command signals are temporarily stored by the secondary output unit in order to respond quickly upon detection of an error.

Abstract: A method by which the each module of a token passing local area network complying with IEEE standard 802.4 determines if the communication cable from which it is receiving signals is faulty and switches to a second, or redundant cable. Each module transmits the same signals over both cables, but can receive signals from only one, its selected cable. In normal operations, all modules receive signals from the same cable. Each of the modules has the capability of detecting faults in its selected cable, and of switching cables so that its second cable becomes its selected cable. Each module also has the capability of initiating the process or re-establising the network whenever a module switches cables in response to detecting a fault. Each module in response to the process of initiating re-establishing the network, switching cables so that all modules are listening to, or receiving signals from the same cable.

Abstract: A process control system includes a primary processor connected to a primary memory via a bus. The primary processor transfers data to be stored to said primary memory. An apparatus of the present invention connected to the bus, collects predetermined data of the data being transferred simultaneously with the transfer of the data to the primary memory. The predetermined data collected by the apparatus is subsequently transferred to a backup processor controller to update the data base of the backup process controller. The apparatus comprises a storage element which stores the data collected. A logic unit controls the operation of the apparatus including the collection of the predetermined data. A control unit of the apparatus transfers the predetermined data stored in the storage element to the backup process controller.

Abstract: A process control system includes a process controller which has a first and second controller, one of the controllers being designated as a primary controller and the other controller being designated as a secondary controller. Each controller has a respective data base. The primary controller performs predefined control functions of the process control system which includes updating the data base associated with the primary controller as a result of performing the predefined control functions. A method for updating the data base associated with the secondary controller comprises the steps of performing the control functions. Results therefrom are utilized to update the data base associated with the primary controller. Simultaneously with updating the data base, predetermined information being stored in the primary data base is collected. At the completion of performing the control functions, the predetermined information which was collected is transferred to the secondary controller.

Abstract: An A/D converter circuit generates a precise digital signal which accurately corresponds to an analog input signal. The A/D converter comprises a converter element, having a first and second, input terminal for receiving control signals, and having an output terminal, and further having at least one analog input terminal. The analog input signal is coupled to the analog input terminal, for converting the analog input signal to an uncorrected digital signal. The uncorrected digital signal includes inaccuracies of the parameter differentials of the converter element. A memory unit, stores information defining the actual parameter values of the converter element. A processor, controls the conversion of the analog input signal to the precise digital signal, wherein the actual parameter values are applied to the uncorrected digital signal thereby removing the inaccuracies of the converter element to obtain the precise digital signal.

Abstract: The lubrication insertions system of the present invention inserts lubricating oil into the critical areas of a bearing. The system comprises a delivery element for delivering lubricating oil to a predetermined point relative to the bearing. The bearing, which is rotating, causes the lubricating oil to be slung outward of the spin axis of the bearing. A cage element, having a lip that extends beyond the edge of the bearing, captures the lubricating oil and directs the lubricating oil into the bearing to the outer race of the bearing and to the rolling elements of the bearing, which track the oil to the inner race of the bearing.

Abstract: A local area network has a plurality of modules, each module having a corresponding timing subsystem. Each timing subsystem includes a clock unit for generating clock pulses, and an a.c. power source. Each timing subsystem is capable of having the timing information generated by each timing subsystem substantially synchronized to the timing information generated by a timing subsystem designated as a master timing subsystem. Each timing subsystem includes a first element, adapted to receive clock pulses and an a.c. reference signal generated from an a.c. power source, which generates timing information from the clock pulses or the a.c. reference signal in response to commands from the module. A register element stores the timing information generated. A second element updates the timing information stored in the register element with timing information included in a timing frame in response to a predetermined command from the module.

Abstract: An apparatus controls the movement of a data block between a peripheral and a data processing system, which comprises a bus which includes an address bus, a first data bus, and a second data bus, the peripheral being connected to the second data bus. A first memory, connected to the second data bus, stores data, and a second memory, connected to the first data bus, stores a plurality of dummy routines in predetermined areas, the predetermined areas of the second memory having corresponding buffer areas in the first memory. The first memory and the second memory correspond to a first memory area and a second memory area within a total predefined memory space, each memory location within the total memory space being defined by a unique memory space address. A processor connected to the first data bus, fetches an instruction, in response to a control signal from the peripheral, from a preselected one of the dummy routines.

Abstract: A bidirectional repeater for Manchester encoded data (MED) signals present on a coaxial cable and fiber optic cable forming the transmission media of a local area network. The repeater receives and then reconstitutes the MED signals present on the coaxial cable and transmits the reconstituted MED signals onto the fiber optic cable. MED data present on the fiber optic cable is received, reconstituted, and transmitted onto the coaxial cable. Signals can be received from only one cable at any one time. Transmission of reconstituted MED signals is terminated when a special set of MED signals identifying the end of a transmission by a module of the network is received.