Intrinsically safe field maintenance tool with power islands

• US 20040218326A1
• Filed: 04/30/2003
• Published: 11/04/2004
• Est. Priority Date: 04/30/2003
• Status: Active Grant

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company), Fisher-Rosemount Incorporated, R. STAHL Schaltgeräte GmbH
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company), R. STAHL Schaltgeräte GmbH
• Inventors: Kamper, Gunter, Duren, Joachim
• Granted Patent: US 7,512,521 B2
• Time in Patent Office: Days
• US Class Current: 361/93.1
• CPC Class Codes: G05B 19/0426 Programming the control sequence
• CPC Class Codes: G05B 2219/23067 Control, human or man machine interface, interactive, HMI, MMI
• CPC Class Codes: G05B 2219/23406 Programmer device, portable, handheld detachable programmer
• CPC Class Codes: G05B 2219/25006 Interface connected to fieldbus
• CPC Class Codes: G05B 2219/25428 Field device
• CPC Class Codes: G05B 23/0213 Modular or universal configuration of the monitoring system, e.g. monitoring system having modules that may be combined to build monitoring program; monitoring system that can be applied to legacy systems; adaptable monitoring system; using different communication protocols
• CPC Class Codes: G08C 19/02 in which the signal transmitted is magnitude of current or voltage G08C19/36, G08C19/38 take precedence

Abstract

A hand held configuration for coupling to a two wire process control loop for use in configuring and monitoring field units coupled to the two wire process control loop is provided which includes a power supply, and at least two power islands. The power islands are configured to electrically isolate electrical components in one power island from electrical components in another power island. Independent power connections are provided between each power island and the power supply.

Claims

1. A hand held configurator for coupling to a two wire process control loop for use in configuring and monitoring field units coupled to the two wire process control loop, comprising:

a power supply;

loop coupling circuitry configured to couple to the two wire process control loop;

at least two power islands configured to electrically isolate electrical components in one power island from electrical components in another power island;

independent power connections between each power island and the power supply; and

a series resistor electrically connecting two power islands to limit energy transfer therebetween.

2. The apparatus of claim 1 including a current limiter in at least one power connection to limit current supplied to a power island.

3. The apparatus of claim 1 including a voltage limiter coupled to at least one power connection to limit voltage applied to the power island.

4. The apparatus of claim 1 wherein at least one of the power islands includes a subpower island therein which is separated by a desired spacing distance and coupled to through at least one series resistor.

5. The apparatus of claim 2 wherein the current limitor comprises an active component.

6. The apparatus of claim 2 wherein the current limitor comprises a passive component.

7. The apparatus of claim 3 wherein the voltage limitor comprises an active component.

8. The apparatus of claim 3 wherein the voltage limitor comprises a passive component.

9. The apparatus of claim 1 wherein at least one power island includes voltage step up circuitry to increase a voltage level within the power island.

10. The apparatus of claim 1 wherein the power supply comprises a battery.

11. The apparatus of claim 1 wherein power supplied to a power island is disconnected if the power draw of the power island exceeds a limit.

12. The apparatus of claim 1 wherein at least one power island includes a microprocessor.

13. The apparatus of claim 1 wherein at least one power island includes loop input/output circuitry for coupling to the two-wire process control loop.

14. The apparatus of claim 1 wherein at least one power island includes a display driver.

15. The apparatus of claim 1 wherein at least one power island includes keyboard circuitry.

16. The apparatus of claim 1 wherein at least one power island includes battery management circuitry.

17. The apparatus of claim 1 wherein the power islands are coupled to ground through electrical connections configured to carry a desired maximum current level.

18. The apparatus of claim 1 wherein a maximum power level supplied to each power island is 1.3 watts.

19. The apparatus of claim 1 including a barrier diode electrically connecting two power islands which operate at differing voltage levels.

20. The apparatus of claim 1 wherein driver and/or level shifter circuits couple to the series resistor are located in close proximity to borders of the power islands to thereby reduce capacitance in a signal pass therebetween.