Universal input and output interface

Patent metadata

Field	Value
Publication number	US-2017366196-A1
Application number	US-201415532675-A
Country	US
Kind code	A1
Filing date	Dec 3, 2014
Priority date	Dec 3, 2014
Publication date	Dec 21, 2017
Grant date	—

Abstract

Provided is programmable circuit for interfacing with a field device. The circuit includes only one analog-to-digital converter (ADC) configured to receive from the field device one from the group including a current signal and a voltage signal. The received one signal has frequency shift keying tones (FSK) superimposed thereon, the ADC being configured to extract information from the received one signal and the FSK tones simultaneously. Also included is only one digital-to-analog converter configured to drive an output signal to the field device, the output signal (i) including one from the group including a current signal and a voltage signal and (ii) being summed with an FSK-modulated signal.

First claim

What is claimed is:

1 . A programmable circuit for interfacing with a field device, the circuit comprising:
only one analog-to-digital converter (ADC) configured to receive, from the field device, one from the group including a first current signal and a first voltage signal, the received one signal having frequency shift keying tones (FSK) superimposed thereon; wherein the ADC is configured to extract information from the received one signal and the FSK tones simultaneously; and only one digital-to-analog converter configured to drive an output signal to the field device, the output signal (i) including one from the group including a second current signal and a second voltage signal and (ii) being summed with an FSK-modulated signal.

2 . A programmable device for interfacing with a field device, the circuit comprising:
a converter module configured to operate as only one of an analog-to-digital converter (ADC) and a digital-to-analog converter (DAC); wherein when the converter module operates as an ADC, the ADC is configured to (i) receive, from the field device, one from the group including a first current signal and a first voltage signal, the received one signal having frequency shift keying tones (FSK) superimposed thereon and (ii) extract information from the received one signal and the FSK tones simultaneously; and wherein when the converter module operates as a DAC, the DAC is configured to drive an output signal to the field device, the output signal (i) including one from the group including a second current signal and a second voltage signal and (ii) being summed with an FSK-modulated signal.

3 . The circuit of claim 1 , wherein the FSK tones are representative of a Highway Addressable Remote Transfer (HART) signal.

4 . The circuit of claim 1 , wherein the FSK-modulated signal is a Highway Addressable Remote Transfer (HART) signal.

5 . The circuit of claim 1 , wherein the field device is a resistance temperature detector (RTD).

6 . The circuit of claim 1 , wherein the field device is a thermocouple.

7 . The circuit of claim 1 , wherein the received one signal is selected from the group including 4-20 mA current signals, 0-5 Volt unipolar signals, 0-10 Volt unipolar signal, +/−5 Volt bipolar, and +/−10 Volt bipolar voltage signals.

8 . The circuit of claim 1 , wherein the output signal is selected from the group consisting of 4-20 mA current signals, 0-5 Volt unipolar signals, 0-10 Volt unipolar signal, +/−5 Volt bipolar, and +/−10 Volt bipolar voltage signals.

9 . A device, comprising:
a field circuit disposed on a field side of a barrier, the field circuit configured to receive a field signal from a field device in one of a digital and analog format, the field circuit including: only one analog-to-digital converter configured to perform a conversion of the field signal on the field side of the barrier to generate a converted signal; and a processing circuit configured to extract a first signal and a second signal from the converted signal, the first signal being a modulated signal based on a Frequency Shift Keying (FSK) protocol.

10 . The device of claim 9 , wherein the processing circuit is configured to:
split the converted signal into two signals paths; and transmit signals from each of the two signal paths to a control device disposed on a control side of the barrier.

11 . The device of claim 10 , wherein the barrier is a galvanic isolation barrier.

12 . The device of claim 11 , wherein the barrier includes non-isolated channels.

13 . The device of claim 9 , wherein the barrier includes an isolated channel.

14 . The device of claim 13 , wherein the isolated channel includes a digital isolator.

15 . The device of claim 9 , wherein the first signal is modulated according to a Highway Addressable Remote Transfer (HART) protocol.

16 . The device according to claim 9 , wherein the field signal is selected from the group consisting of current signals and voltage signals.

17 . The device of claim 9 , wherein the second signal is a non-modulated signal.

18 . The device of claim 9 , wherein the field circuit is configured to receive a signal from the field device in a mode selected from the group of modes consisting of discrete level input mode, discrete level output mode, and voltage input mode.

19 . A device, comprising:
a field circuit disposed on a field side of a barrier, the field circuit configured to receive a control signal from a control device in one of a digital and analog format, the control device disposed on a control side of the barrier, and the field circuit including: only one digital-to-analog converter configured to perform a conversion of the control signal on the field side of the barrier to create a converted signal; and a summing circuit configured to generate an output signal, the output signal comprising a first signal being modulated according to a Frequency Shift Keying (FSK) protocol and superimposed on the converted signal.

20 . The device of claim 19 , wherein the converted signal is a non-modulated signal.

21 . The device of claim 19 , wherein the first signal is modulated according to a Highway Addressable Remote Transfer (HART) protocol.

Assignees

• Gen Electric

Inventors

• Lovell Alan Carroll
• Henderson Bruce

Classifications

• G01K7/16

  using resistive elements · CPC title

• H03C3/00

  Angle modulation (H03C5/00, H03C7/00 take precedence) · CPC title

• G01K7/021

  Particular circuit arrangements (G01K7/026, G01K7/12, G01K7/14 take precedence) · CPC title

• H03M1/004 Primary

  Reconfigurable analogue/digital or digital/analogue converters (H03M1/02 takes precedence) · CPC title

• H04L27/10 Primary

  Frequency-modulated carrier systems, i.e. using frequency-shift keying (H04L27/32 takes precedence) · CPC title