Control switch with integrated RFID tag

• US 9,514,899 B2
• Filed: 04/28/2015
• Issued: 12/06/2016
• Est. Priority Date: 12/29/2014
• Status: Expired due to Fees

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Blackwood, Andrew James
• Primary Examiner(s): BLOUIN, MARK S
• Application Number:
  US14/697,801
• Publication Number:
  US 20160189888A1
• Time in Patent Office: 588 Days
• Field of Search: 340/10.5
• US Class Current: 1/1
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications
• CPC Class Codes: H01H 21/28 adapted for actuation at a limit or other predetermined position in the path of a body, the relative movement of switch and body being primarily for a purpose other than the actuation of the switch, e.g. door switch, limit switch, floor-levelling switch of a lift
• CPC Class Codes: H01H 2300/032 using RFID technology in switching devices
• CPC Class Codes: H01H 9/0271 structurally combining a switch and an electronic component for relays H01H50/021
• CPC Class Codes: H01H 9/168 making use of an electromagnetic wave communication
• CPC Class Codes: H01H 9/54 Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/14 Protecting elements, switches, relays or circuit breakers

Abstract

A control system for controlling operation of a field device includes a switch having a switch contact movable between an off position and an activated position, a radio frequency identification (RFID) tag integrated with the switch and in selective communication with the switch based on the position thereof, an RFID reader configured to receive switch messages from the RFID tag that indicate an operational state of the switch, and a control circuit configured to receive switch messages from the RFID reader, the control circuit receiving the switch messages for purposes of controlling the field device.

Claims

1. A control system for controlling operation of a field device, the control system comprising:

a switch having a switch contact movable between an off position and an activated position;

a radio frequency identification (RFID) tag integrated with the switch and in selective communication with the switch based on the position thereof;

an RFID reader configured to receive switch messages from the RFID tag that indicate an operational state of the switch;

a control circuit configured to receive switch messages from the RFID reader, the control circuit receiving the switch messages for purposes of controlling the field device; and

an antenna integrated with the switch and selectively in operable communication with the RFID tag based on the position of the switch contact;

wherein the switch contact forms a communications path between the RFID tag and the antenna when in the activated position; and

wherein the antenna generates a switch message for transmission to the RFID reader when the communications path is formed between the RFID tag and the antenna.

2. The control system of claim 1 wherein the switch comprises a limit switch whose switch contact moves between the off position and the activated position based on a movement of the field device relative to the limit switch.

3. The control system of claim 2 wherein the limit switch comprises a spring loaded limit switch or a reed switch.

4. The control system of claim 1 further comprising a potting housing the switch and the RFID tag, so as to protect the switch and the RFID tag from a caustic environment.

5. The control system of claim 1 wherein the control system comprises an intrinsically safe control system, with the switch and the RFID tag being located in a hazardous environment and the RFID reader and control circuit being located in an intrinsically safe environment.

6. The control system of claim 5 wherein power in or provided to the RFID tag is limited such that it remains below prescribed voltage and current intrinsic safety limits.

7. The control system of claim 1 wherein the RFID reader transmits interrogator signals to the RFID tag, with the RFID tag generating switch messages responsive to the interrogator signals.

8. The control system of claim 1 wherein the RFID tag includes thereon a unique identifier tied to a function of the switch, with each switch message received by the RFID reader including the unique identifier of the RFID tag.

9. A limit switch control system for controlling operation of a field device, the limit switch control system comprising:

a limit switch including a switch contact movable between an off position and an activated position, the switch contact movable between the off position and the activated position responsive to a movement or positioning of the field device relative to the limit switch;

a radio frequency identification (RFID) tag integrated with the limit switch, the RFID tag including thereon a unique identifier tied to a function of the limit switch in its activated position; and

an antenna integrated with the limit switch and selectively in operable communication with the RFID tag based on a position of the switch contact;

wherein a communications path between the RFID tag and the antenna is formed by the switch contact when the limit switch is in the activated position, thereby causing the antenna to transmit a switch signal to an RFID reader remote from the limit switch, the switch signal including therein the unique identifier of the RFID tag.

10. The limit switch control system of claim 9 wherein the limit switch comprises a spring loaded limit switch or a reed switch.

11. The limit switch control system of claim 9 further comprising a potting housing the limit switch, the RFID tag and the antenna so as to protect the limit switch, the RFID tag and the antenna from a caustic environment.

12. The limit switch control system of claim 9 wherein the RFID tag comprises an active tag configured to communicate with the RFID reader from a remote location.

13. The limit switch control system of claim 10 wherein the switch signal transmitted to the RFID reader from the RFID tag comprises a data message transmittable on a communications link connected to the RFID reader.

14. An intrinsically safe control system for controlling operation of a field device, the intrinsically safe control system comprising:

a switch having a switch contact movable between an off position and an activated position;

a radio frequency identification (RFID) tag integrated with the switch;

an antenna operable with the RFID tag to transmit switch messages indicative of an operational state of the switch, wherein movement of the switch between the off position and the activated position selectively provides a communications path between the RFID tag and the antenna;

a control circuit in operable communication with the switch via transmission of the switch messages thereto, with the switch messages causing the control circuit to control operation of the field device.

15. The intrinsically safe control system of claim 14 further comprising an RFID reader configured to:

receive switch messages from the antenna and the RFID tag based on actuation of the switch to the activated position; and

transmit the switch messages to the control circuit.

16. The intrinsically safe control system of claim 14 wherein the switch, RFID tag and antenna are located in a hazardous environment and the RFID reader and control circuit ate located in an intrinsically safe environment, with power in or provided to the RFID tag being limited such that it remains below prescribed voltage and current intrinsic safety limits.

17. The intrinsically safe control system of claim 14 wherein the RFID tag includes thereon a unique identifier tied to a function of the switch, with each switch message received by the RFID reader including the unique identifier of the RFID tag.

18. The intrinsically safe control system of claim 14 wherein the switch comprises a limit switch whose switch contact moves between the off position and the activated position based on a movement of the field device relative to the limit switch.