Rosemount Inc.

Agilent Technologies, Inc.

Other

Rosemont Inc.

Jogesh Warrior

Evren Eryurek

Gary A Lenz

Gregory C Brown

Kelly Michael Orth

John C Eidson

Craig R Tielens

Vincent C Jacobson

Steven R Esboldt

Jane B Lanctot

Scott E Brigham

Ken A Nishimura

Andrew Timothy Patten

Jerry J Liu

David Erich Tetzlaff

Hans J Sitte

Hehong Zou

Gabriel A Maalouf

Coy L Hays

Jeff Burch

Jayendra Das

Kale P Hedstrom

The area density of broadcast stations having respective service areas and broadcasting on the same channel is increased without exceeding a specified level of co-channel interference within the service areas by a method in which the field strength of the signal transmitted by the first broadcast station is monitored, and a field strength determining property of the first broadcast station is controlled in response to the monitoring.

System and method for increasing area density of terrestrial broadcast stations

Representative embodiments are directed to distributed sensor systems from which measurement data is extracted using mobile devices. Representative embodiments record access attempts by the mobile devices and calculate the probabilities of future access by a mobile device to sensor devices using the recorded information. Collection points are selected in response to the probabilities of future access. Additionally, memory management and data prioritization may occur that is at least partially dependent upon the probabilities of future access.

Method for cluster head selection in networks accessed by mobile devices

A system and method are provided that use mobile collectors for accessing a wireless sensor network. In certain embodiments, one or more mobile collectors having mobility that is unpredictable to a wireless sensor network are deployed for use in accessing the wireless sensor network. Thus, rather than relying on an access technique having certainty designed therein with regard to the access of a wireless sensor network, certain embodiments utilize an access technique that relies on statistical probability for accessing the wireless sensor network. For instance, by deploying a plurality of mobile collectors that are operable for accessing a wireless sensor network, a statistical probability exists that at some point (or at various points in time) at least one of the mobile collectors will travel within range of the wireless sensor network to enable access thereof.

System and method for using mobile collectors for accessing a wireless sensor network

A distributed system with an architecture based on synchronized clocks that provides accurate coordination of control functions. The distributed system includes a set of nodes coupled to a communication link. Each node has a clock which holds a real-world time. The nodes participate in a synchronization protocol on the communication link for synchronizing the real-world time in each clock. The architecture of the distributed system is such that the synchronization of control functionality in the distributed system is based upon the real-world time in the clocks. A variety of examples of applications for this architecture are set forth.

Distributed control system architecture based on synchronized clocks

A process device couples to a process control loop. The process device receives process signals. A memory in the process device contains a nominal parameter value and a rule. Computing circuitry calculates a statistical parameter of the process signal and operates on the statistical parameter and the stored nominal value based upon the stored rule and responsively provides an event output based upon the operation. Output circuitry provides an output in response to the event output. The statistical parameter can be used in statistical process control systems.

Device in a process system for determining statistical parameter

A process device couples to a process control loop. The process device receives a process signal. A memory in the process device contains a nominal parameter value. Computing circuitry provides an event output based upon the stored nominal value and the process signal. Output circuitry provides an output in response to the event output.

Transmitter with software for determining when to initiate diagnostics

A transmitter in a process control system includes a resistance-based sensor sensing a process variable and providing a sensor output. Self heating circuitry coupled to the sensor provides a self heating signal related to the sensor. Analog-to-digital conversion circuitry coupled to the sensor output provides a digitized sensor output, and transmitter output diagnostic correction circuitry provides an auto corrected output as a function of the self heating signal output or in another embodiment, the transmitter outputs a residual life estimate of the sensor as a function of the self heating index. A novel method of calculating the self heating index is also disclosed, which is applicable to various methods for providing a diagnostic transmitter output.

Auto correcting temperature transmitter with resistance based sensor

A device in a process control system includes an electrical element which has a resistance. Self heating circuitry coupled to the element provides a self heating signal related to the resistance of the element. Diagnostic circuitry provides a diagnostic output as a function of the self heating signal output.

Resistance based process control device diagnostics

A process device couples to a process control loop. The process device receives process signals. A memory in the process device contains a nominal parameter value and a rule. Computing circuitry calculates a statistical parameter of the process signal and operates on the statistical parameter and the stored nominal value based upon the stored rule and responsively provides an event output based upon the operation. Output circuitry provides an output in response to the event output

Device in a process system for detecting events

A process device couples to a process control loop. The process device receives process signals. A memory in the process device contains a nominal parameter value and a rule. Computing circuitry calculates a statistical parameter of the process signal and operates on the statistical parameter and the stored nominal value based upon the stored rule and responsively provides an event output based upon the operation. Output circuitry provides an output in response to the event output.

A circuit for compensating variables in a measurement transmitter. Within the transmitter, a sensor senses a primary process variable such as differential pressure and a converter digitizes the sensed process variable. The sensor senses pressures within a span of pressures values. A memory inside the transmitter stores at least two membership functions, each membership function having a non-zero value over a predetermined region of the process variable span and a substantially zero value over the remainder of the span. The memory also stores a set of compensation formulas, each formula corresponding to a membership function. A selection circuit in the transmitter selects those membership functions which have a non-zero value at the digitized process variable and a correction circuit provides at least one correction value, each correction value calculated from a compensation formula corresponding to a selected membership function. A weighting circuit multiplies each correction value by its corresponding selected membership function, and combines the multiplicands to provide a compensated process variable. The compensated process variable is coupled to a control circuit connecting the transmitter to a control system.

Transmitter with improved compensation

The present invention includes a process control instrument having an improved data bus protocol for facilitating communications between master and slave nodes. The process control instrument includes a microprocessor operating in accordance with the SPI data bus protocol, first and second peripheral devices, and a data bus coupled to the microprocessor and the first and second peripheral devices. The improved data bus protocol used in the process control instruments of the present invention provides numerous advantages such as reduced printed circuit board space requirements and greater interchangeability of peripheral and master node components.

Field instrument with data bus communications protocol

A smart field-mounted control unit, for controlling a process, receives signals and sends a command output over a two-wire circuit which powers the control unit. An input section receives the signals, which can be instructions representative of commands or instruction sets, process variables sensed by external control units or setpoints representative of a desired process state. The instructions are representative of a control requirement of the process and adjust a controlling section in the control unit to generate the command output in conformance with the control requirement. The command output can be a function of the difference between the process setpoint and a process variable, or a function of a linear combination of a process variable and its calculated time integral and time derivative functions. A sensing section in the control unit can sense and scale a process variable for generating the command output as well. The control unit can include a regulator section, controlled by the command output, which regulates application of a mechanical, hydraulic, pneumatic or electromagnetic force applied to the process.

Field-mounted control unit

A field device such as a transmitter in a process control system includes conversion circuitry coupled between Fieldbus interface circuitry and transmitter interface circuitry. The transmitter includes a transducer for sensing a process variable and providing a transducer output. Measurement circuitry couples to the transducer output, processes the transducer output and provides a measurement output. The transmitter interface circuitry couples to the measurement circuitry and provides an interface output representative of the measurement output. Further, the transmitter interface circuitry receives a transmitter command and responds in accordance with the transmitter command. The Fieldbus interface circuitry is adapted to couple to a process control loop which operates in accordance with the Fieldbus standard.

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Chanhassen, MN, United States of America

Jogesh Warrior