FIELD DEVICE CONFIGURED FOR WIRELESS DATA COMMUNICATION

• US 20070229255A1
• Filed: 05/25/2007
• Published: 10/04/2007
• Est. Priority Date: 10/27/2000
• Status: Active Grant

• Current Assignee: Schneider Electric Systems USA, Inc. (Schneider Electric SE)
• Original Assignee: Invensys Systems Incorporated (Invensys PLC)
• Inventors: Loechner, Michael
• Granted Patent: US 7,593,642 B2
• Time in Patent Office: Days
• US Class Current: 340/540
• CPC Class Codes: G05B 19/4185 characterised by the network communication
• CPC Class Codes: G05B 2219/25283 Evaluate available energy prior to wireless transmitter-receiver activation
• CPC Class Codes: G05B 2219/31121 Fielddevice, field controller, interface connected to fieldbus
• CPC Class Codes: G05B 2219/31251 Redundant access, wireless and hardware access to fielddevices
• CPC Class Codes: G05B 2219/33182 Uart, serial datatransmission, modem
• CPC Class Codes: G05B 2219/33192 Radio link, wireless
• CPC Class Codes: G05B 2219/33198 Laser, light link, infrared
• CPC Class Codes: G05B 2219/33206 Ultrasonic
• CPC Class Codes: G05B 2219/34313 Power supply for communication delivered by, derived from 4-20-mA current loop
• CPC Class Codes: G05B 2219/34481 EFC explosion free control, intrinsically safe
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Field devices comprising a transmitter and/or receiver for wireless data communication are provided. The energy available for wireless data communication in data transmitting or data receiving field devices is evaluated prior to activation of the transmitter and/or receiver of the field device.

Claims

1. A field device comprising:

at least one actuator and/or sensor configured to alter and/or sense a control and/or process variable in a manufacturing field;

a wireless transmitter and/or receiver configured for wireless data communication between the field device and a remote device when activated;

an interface configured to receive operating power;

an energy buffer configured to store energy from the received operating power and to supply the stored energy to the wireless transmitter and/or receiver during wireless data communication; and

a controller configured to evaluate the stored energy available in the energy buffer prior to activation of the wireless transmitter and/or receiver and delay activation of the wireless transmitter and/or receiver when the evaluation indicates that the stored energy in the energy buffer is insufficient to sustain operation of the wireless transmitter and/or receiver during wireless data communication.

2. The field device of claim 1 wherein the controller is configured to split an input data stream into a plurality of data segments for subsequent wireless data transmission.

3. The field device of claim 2 wherein the controller is configured to evaluate the stored energy for each one of the plurality of data segments.

4. The field device of claim 1 wherein the wireless transmitter and/or receiver comprises an infrared transmitter, the infrared transmitter comprising:

a light emitting unit connected to a power supply line and to ground and emitting infrared waveforms according to driving pulses outputted by a coder unit; and

wherein the energy buffer is coupled across the light emitting unit to supply energy to the light emitting unit.

5. The field device of claim 4 further comprising a first resistor and a second resistor connected in series between the power supply line and the light emitting unit, wherein the energy buffer is connected to a node between the first resistor and the second resistor, the first resistor being configured to limit a charge current of the energy buffer.

6. The field device of claim 5 wherein the second resistor is variable to change the irradiance of the light emitting unit according to a predetermined data exchange distance.

7. The field device of claim 1 wherein the energy buffer comprises a capacitor.

8. The field device of claim 1 wherein the controller comprises a voltage monitor to evaluate the energy stored in the energy buffer.

9. A method for exchanging data in a manufacturing plant control system using wireless data communication, the method comprising:

receiving operating power at a field device that includes a wireless transmitter and/or receiver;

storing, at the field device, energy from the received operating power;

evaluating the stored energy prior to activation of the wireless transmitter and/or receiver; and

delaying activation of the wireless transmitter and/or receiver when the evaluation indicates that the stored energy in the energy buffer is insufficient to sustain operation of the wireless transmitter and/or receiver during wireless data communication.

10. The method of claim 9 further comprising splitting an input data stream into a plurality of data segments for subsequent wireless data transmission.

11. The method of claim 10 wherein evaluating the stored energy prior to activation of the wireless transmitter and/or receiver comprises evaluating the stored energy for each one of the plurality of data segments.

12. The method of claim 9 wherein evaluating the stored energy prior to activation of the wireless transmitter and/or receiver comprises evaluating the stored energy using a voltage monitor.

13. The method of claim 9 wherein storing, at the field device, energy from the received operating power comprises storing the energy in an energy buffer.

14. The method of claim 13 wherein the energy buffer comprises a capacitor.

15. The method of claim 9 further comprising activating the wireless transmitter and/or receiver for wireless data communication.

16. The method of claim 15 further comprising providing the stored energy to the wireless transmitter and/or receiver from the energy buffer during wireless data communication.

17. A computer-useable storage medium storing a program that is loadable into a memory of a field device, wherein the field device stores energy from received operating power, the program including software code for exchanging data in a manufacturing plant control system using a wireless transmitter and/or receiver of the field device by causing a controller of the field device to:

store, at the field device, energy from the received operating power;

evaluate the stored energy prior to activation of the wireless transmitter and/or receiver; and

delay activation of the wireless transmitter and/or receiver when the evaluation indicates that the stored energy in the energy buffer is insufficient to sustain operation of the wireless transmitter and/or receiver during wireless data communication.

18. The medium of claim 17 wherein the program includes software code for causing the controller of the field device to split an input data stream into a plurality of data segments for subsequent wireless data transmission.

19. The medium of claim 18 wherein, to evaluate the stored energy prior to activation of the wireless transmitter and/or receiver, causing a controller of the field device to evaluate the stored energy for each one of the plurality of data segments.

20. The medium of claim 17 wherein the program includes software code for causing a controller of the field device to provide the stored energy to the wireless transmitter and/or receiver during wireless data communication.