Communication system for process field device

Patent metadata

Field	Value
Publication number	US-9264787-B2
Application number	US-95518510-A
Country	US
Kind code	B2
Filing date	Nov 29, 2010
Priority date	Nov 29, 2010
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A field device for use in an industrial process, includes a process interface element configured to measure or control a process variable. Communication circuitry is configured to communicate with another location. A communication system is configured to provide communications between at least two components in the field device. A signal inverter couples an inverted signal from the communication system to other circuitry to thereby reduce interference received by the other circuitry.

First claim

What is claimed is:

1. A field device for use in controlling or monitoring a process variable of an industrial process, comprising:
a process interface element configured to measure or control the process variable of the industrial process;
a first communication system including a single ended transmitter and receiver;
a second communication system configured to provide communications between at least two second components, the second communication system comprising a signal source that produces a signal that couples to the first communication system through electromagnetic intersystem coupling to form an interference signal in the first communication system;
a signal inverter coupled to the output of the signal source and configured to receive and invert the signal produced by the signal source to produce an inverted signal that is the inverse of the signal produced by the signal source and couples to the first communication system through electromagnetic intersystem coupling to produce an injected signal in the first communication system to thereby reduce interference from the second communication system to the first communication system, wherein the injected signal has a phase, amplitude and wave shape which are an inversion of the interference signal; and
wherein the field device is configured to communicate with another location in the industrial process;
wherein the first and second communication systems communicate digital information and the first communication system comprises loop input/output circuitry used to communicate with a remote location over a process control loop and the second communication system comprises local databus communication circuitry used to communicate locally.

2. The field device of claim 1 wherein the first communication system is configured to communicate with the another location in the industrial process.

3. The field device of claim 1 wherein the second communication system includes a local databus.

4. The field device of claim 1 wherein the process interface element comprises a process variable sensor.

5. The field device of claim 1 wherein the process interface element comprises a control element.

6. The field device of claim 1 wherein at least one of the first and second communication systems includes a wireless databus.

7. The field device of claim 1 wherein at least one of the first and second communication systems comprises a single ended communication system.

8. The field device of claim 1 including a second signal inverter configured to invert a signal carried on the first communication system to form an inverted signal that is coupled to the second communication system by electromagnetic intersystem coupling to thereby reduce interference from the first communication system to the second communication system.

9. A method for use in a field device of the type used to control or monitor a process variable in an industrial process, the method for providing communications between components:
interfacing with the industrial process through a process interface configured to measure or control the process variable of the industrial process;
communicating data between at least two first components over a first databus between a single ended transmitter and a single ended receiver;
communicating data between at least two second components over a second databus, wherein at least one of the two second components is located in the field device;
obtaining a communication signal sent between the at least two components on the second databus;
inverting the communication signal to form an inverted signal that is an inversion of the communication signal; and
injecting the inverted signal onto the first databus through electromagnetic intersystem coupling to thereby reduce an interference signal formed on the first databus through electromagnetic intersystem coupling of the communication signal, wherein the injected signal introduced on the first databus through electromagnetic intersystem coupling has a phase, amplitude and wave shape which are an inversion of the interference signal;
wherein the field device is configured to communicate with another location in the industrial process;
wherein the first and second databuses communicate digital information and the first databus couples to loop input/output circuitry used to communicate with a remote location over a process control loop and the second databus couples to local databus communication circuitry used to communicate locally.

10. The method of claim 9 wherein the first databus is configured to communicate with the another location in the industrial process.

11. The method of claim 9 wherein the second databus includes a local databus.

12. The method of claim 9 wherein at least one of the first and second databuses includes a wireless databus.

13. The method of claim 9 wherein at least one of the first and second databuses comprises a single ended databus.

14. The method of claim 9 including providing a second inverted signal from the first databus to the second databus to thereby reduce interference.

Assignees

• Korolev Eugene
• Schulte John P
• Rosemount Inc

Inventors

• Korolev Eugene
• Schulte John P

Classifications

• H04Q2209/40

  using a wireless architecture · CPC title

• H04B3/32

  Reducing cross-talk, e.g. by compensating · CPC title

• H04Q2209/10

  using a centralized architecture · CPC title

• H04Q9/00 Primary

  Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom · CPC title

• H04B1/7107

  Subtractive interference cancellation · CPC title