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PROCESS VARIABLE TRANSMITTER WITH SELF-LEARNING LOOP DIAGNOSTICS

  • US 20170093533A1
  • Filed: 09/30/2015
  • Published: 03/30/2017
  • Est. Priority Date: 09/30/2015
  • Status: Active Grant
First Claim
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1. A two-wire process variable transmitter for use in an industrial process, comprising:

  • a process variable sensor configured to sense a process variable of a process fluid of the industrial process;

    output circuitry configured to provide an output on a two-wire process control loop which is related to the sensed process variable;

    terminal voltage measurement circuitry configured to measure a voltage related to a terminal voltage of the process variable transmitter, the terminal voltage comprising a voltage measured across an electrical connection of the two-wire process variable transmitter to the two-wire process control loop;

    a microprocessor configured to perform loop diagnostics on the two-wire process control loop based upon a determined loop current and the measured terminal voltage, wherein the microprocessor determines coefficients of a polynomial equation which relates loop current and terminal voltage during normal operation of the two-wire process variable transmitter and performs subsequent diagnostics based upon the coefficients of the polynomial.

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