Rosemount Inc.

Rosemont Inc.

Gabriel A Maalouf

David Erich Tetzlaff

Jogesh Warrior

Kevin B Moore

Roger Benson

Stephen D Anderson

Dale Warren Borgeson

Paul D Kammann

Daniel V Hulse

Carro Lynel Boyd

A field device is configured to send and receive data over an industrial process network. The field device includes a processor and a communications unit communicatively connected to the industrial process network. The communications unit is configured to send and receive the data over the industrial process network via a first communications protocol at a first data rate. The communications unit is connected to communicate with the processor via a second communications protocol at a second data rate that is greater than the first data rate.

Communications unit for an industrial process network

A receiver receives modulated message signals in non-coherent FSK and coherent 8PSK protocols. A selectively configurable processor demodulates the message signals, and includes a demodulator that derives in-phase and quadrature signals based on the message signals. A phase detector is responsive to the in-phase and quadrature signals and delayed in-phase and quadrature signals to derive a phase signal. A selector is responsive to the in-phase and quadrature signals to selectively connect a loop filter between the phase detector and the demodulator. When the selector connects the filter between the phase detector and demodulator, the demodulator is responsive to filtered phase signals to lock onto a frequency of the message signals so that the processor operates as a phase locked loop to demodulate coherent modulated signals. When the selector disconnects the filter from between the phase detector and the demodulator, the demodulator demodulates non-coherent modulated signals and the phase detector supplies a phase signal representing the slope of the phase of the demodulated signal.

Method and apparatus for demodulating coherent and non-coherent modulated signals

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

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Minneapolis, MN, United States of America

Gabriel A Maalouf