Portable field maintenance tool configured for multiple process control communication protocols

Patent metadata

Field	Value
Publication number	US-10599134-B2
Application number	US-201615217757-A
Country	US
Kind code	B2
Filing date	Jul 22, 2016
Priority date	Jul 22, 2016
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A portable field maintenance tool may perform one or more tasks, such as communicating with a field device, powering a field device, diagnosing a field device, or diagnosing a communication link in a plant environment to which a field device is connected. The portable field maintenance tool may interact with field devices configured according to a number of different communication protocols, such as the HART protocol and the Fieldbus protocol. The portable field maintenance tool may be energy limited and fault tolerant, and may operate in compliance with Intrinsic Safety standards, enabling use of the portable field maintenance tool in hazardous areas.

First claim

What is claimed is:

1. A portable field maintenance tool comprising:
(A) a housing;
(B) a communication interface disposed through the housing, the communication interface including an internal portion accessible within the housing;
(C) one or more communication circuits disposed within the housing and electrically connected to the internal portion of the communication interface, the one or more communication circuits configured to communicate according to a first protocol and to communicate according to a second protocol; and
(D) one or more power supplies disposed within the housing and electrically connected to the internal portion of the communication interface, the one or more power supplies configured to supply power according to the first protocol and to supply power according to the second protocol; and
wherein the communication interface further includes one or more terminals that are:
(i) connectable to a first field device so that the first field device receives a first composite signal including a first power signal and a first communication signal, wherein the first composite signal is configured, according to the first protocol, to supply power via the first power signal from the one or more power supplies to the first field device and to communicatively connect the first field device to the one or more communication circuits; and
(ii) connectable to a second field device so that the second field device receives a second composite signal including a second power signal and a second communication signal, wherein the second composite signal is configured, according to the second protocol, to supply power via the second power signal from the one or more power supplies to the second field device and to communicatively connect the second field device to the one or more communication circuits;
wherein the first power signal conforms to a first set of requirements associated with the first protocol and the second power signal conforms to a second set of requirements, different from the first set of requirements, associated with the second protocol;
wherein the first field device is configured to be powered by power signals conforming to the first set of requirements associated with the first protocol; and
wherein the second field device is configured to be powered by power signals conforming to the second set of requirements associated with the second protocol.

2. The portable field maintenance tool of claim 1 , wherein the one or more communication circuits are configured to communicate according to the first protocol by way of a digital amplitude modulation (AM) communication signal.

3. The portable field maintenance tool of claim 1 , wherein the one or more communication circuits are configured to communicate according to the second protocol by way of a digital frequency modulation (FM) communication signal.

4. The portable field maintenance tool of claim 1 , wherein the first protocol is a HART protocol and the second protocol is a Fieldbus protocol.

5. The portable field maintenance tool of claim 1 , wherein the one or more communication circuits include:
a first communication circuit configured to communicate according to the first protocol; and
a second communication circuit configured to communicate according to the second protocol.

6. The portable field maintenance tool of claim 5 , wherein the one or more power supplies include:
a first power supply configured to supply power according to the first protocol; and
a second power supply configured to supply power according to the second protocol.

7. The portable field maintenance tool of claim 6 , wherein the one or more terminals include:
a first pair of terminals electrically connected to the first communication circuit and to the first power supply, wherein the first composite signal is transmitted via the first pair of terminals to the first field device; and
a second pair of terminals that is electrically connected to the second communication circuit and to the second power supply, wherein the second composite signal is transmitted via the second pair of terminals to the second field device.

8. The portable field maintenance tool of claim 7 , further comprising:
one or more energy measurement circuits electrically connected to the first pair of terminals and to the second pair of terminals, the one or more energy measurement circuits configured to measure at the first pair of terminals one or more electrical characteristics of the first composite signal and to measure at the second pair of terminals one or more electrical characteristics of the second composite signal.

9. The portable field maintenance tool of claim 1 , wherein the one or more power supplies and the one or more communication circuits are configured to avoid exceeding intrinsic safety energy levels.

10. The portable field maintenance tool of claim 1 , wherein the first composite signal includes an analog DC communication signal and a digital FM communication signal superimposed on the analog DC communication signal.

11. A method for communicating with a field device, the method including:
communicatively connecting a portable field maintenance tool to a first field device configured according to a first protocol;
transmitting by the portable field maintenance tool a first composite signal configured according to the first protocol, the first composite signal including: (i) a first power signal, conforming to a first set of requirements associated with the first protocol, to power the first field device, and (ii) a first communication signal to communicate with the first field device;
communicatively connecting a portable field maintenance tool to a second field device configured according to a second protocol; and
transmitting by the portable field maintenance tool a second composite signal configured according to the second protocol, the second composite signal including: (i) a second power signal, conforming to a second set of requirements, distinct from the first set of requirements, associated with the second protocol, to power the second field device, and (ii) a second communication signal to communicate with the second field device;
wherein, to be powered, the first field device requires a power signal conforming to the first set of requirements of the first protocol; and
wherein, to be powered, the second field device requires a power signal conforming to the second set of requirements of the second protocol.

12. The method of claim 11 , wherein transmitting the first composite signal configured according to the first protocol comprises:
transmitting the first composite signal according to a digital amplitude modulation (AM) protocol.

13. The method of claim 11 , wherein transmitting the second composite signal configured according to the second protocol comprises:
transmitting the second composite signal according to a digital frequency modulation (FM) protocol.

14. The method of claim 11 , wherein transmitting the first composite signal configured according to the first protocol comprises:
transmitting the first composite signal according to a HART protocol.

15. The method of claim 11 , wherein transmitting the second composite signal configured according to the first protocol comprises:
transmitting the second composite signal according to a Fieldbus protocol.

16. The method of claim 11 , wherein transmitting the first composite signal includes ramping the first power signal over a time period.

17. The method of claim 11 , wherein:
communicatively connecting the portable field maintenance tool to

Assignees

• Fisher Rosemount Systems Inc

Inventors

• Benson Roger
• Ferguson Anthony D
• Toepke Todd M

Classifications

• G05B2219/25008

  Different buses, protocols on same line, also dsl · CPC title

• G05B19/4186 Primary

  by protocol, e.g. MAP, TOP · CPC title

• G05B2219/25006

  Interface connected to fieldbus · CPC title

• G08B21/185

  Electrical failure alarms · CPC title

• G05B19/0423 Primary

  Input/output · CPC title