Patent ID: 9217653
Filing Date: 2015-12-22
Classification: G01D

Abstract:
1. A process transmitter for monitoring pressure of a process, comprising: at least one pressure sensor which monitors a process pressure; analog-to-digital (A/D) converter circuitry coupled to the at least one pressure sensor and configured to provide process pressure data indicative of process pressure values; a digital signal processor (DSP) coupled to the A/D converter circuitry to receive the process pressure data, the DSP comprising a co-processor configured to receive and perform calculations on the process pressure data from the A/D converter circuitry to generate output data from the co-processor of the DSP based upon a polynomial equation and stored polynomial coefficients; communications circuitry configured to control communication with the process transmitter and transmit the output data from the co-processor of the DSP received from the DSP, wherein a first portion of the communications circuitry includes a digital communications modem; a microprocessor, separate from the co-processor of the DSP, the separate microprocessor coupled between the co-processor and the communications circuitry and configured to process the output data from the co-processor of the DSP and to provide the output data from the co-processor of the DSP to the digital communications modem of the communications circuitry for the communication from the process transmitter to provide a first data path for the output data from the co-processor of the DSP to the communications circuitry, wherein the DSP, the separate microprocessor and the communications circuitry are configured to provide the first data path for the output data from the co-processor of the DSP, through the separate microprocessor, to the digital communications modem of the communication circuitry without further processing by the co-processor of the DSP after processing by the separate microprocessor; wherein the DSP is also coupled to a second portion of the communications circuitry and is configured to provide a second shorter latency data path which bypasses the separate microprocessor for controlling the communications circuitry to communicate the output data from the co-processor of the DSP with reduced latency as compared to the communication of the output data from the co-processor of the DSP using the separate microprocessor and the first data path, wherein the DSP and the communications circuitry are configured to provide the second data path for the output data from the co-processor of the DSP to the second portion of the communications circuitry without processing by the separate microprocessor; wherein the process transmitter is configured to be coupled to loop wiring and the communications circuitry is configured to control the communication over the loop wiring, and further comprising an output circuit configured to be coupled to the loop wiring to control a 4-20 mA current on the loop wiring; and wherein the communications circuitry comprises: loop power circuitry configured to control the 4-20 mA current on the loop wiring; the digital communications modem coupled to the output circuit and configured to control the output circuit to communicate over the loop wiring using a digital communications protocol; and a digital-to-analog converter (DAC) coupled to the output circuit and configured to provide an analog signal to the output circuit to thereby control the 4-20 mA current on the loop wiring.