Data communication in a multi-wire irrigation control system

• US 8,260,465 B2
• Filed: 07/17/2009
• Issued: 09/04/2012
• Est. Priority Date: 07/17/2009
• Status: Active Grant

• Current Assignee: Rain Bird Corporation
• Original Assignee: Rain Bird Corporation
• Inventors: Crist, Timothy J.
• Primary Examiner(s): Hartman, Jr., Ronald
• Application Number:
  US12/505,401
• Publication Number:
  US 20110015800A1
• Time in Patent Office: 1,145 Days
• Field of Search: 700/284, 375/268, 375/353
• US Class Current: 700/284
• CPC Class Codes: A01G 25/16 Control of watering
• CPC Class Codes: Y02A 40/22 Improving land use; Improving water use or availability; Controlling erosion

Abstract

An irrigation control device having a modulator that modulates data onto an alternating power signal by distorting amplitude of a first leading portion of selected cycles of the alternating power signal, and permit effectively a full amplitude of the alternating power signal on a following portion of the selected cycles, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal. The irrigation control device further includes an interface configured to couple the modulator to a multi-wire interface coupled to a plurality of irrigation devices to permit the alternating power signal to be applied to the multi-wire interface.

Claims

1. A method for providing power and data to an irrigation device, the method comprising:

modulating data onto an alternating power signal by distorting an amplitude of a first leading portion of selected cycles of the alternating power signal;

permitting effectively a full amplitude of the alternating power signal on a following portion of the selected cycles, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal;

applying the alternating power signal to a multi-wire interface configured to couple with a plurality of irrigation devices; and

balancing the alternating power signal by distorting an amplitude of a second leading portion of the selected cycles, wherein the second leading portion is on either the high side of the cycle or the low side of the cycle and is opposite to a side of the first leading portion.

2. The method according to claim 1, wherein the distorting of the amplitude is performed by clipping the first leading portion.

3. The method according to claim 1, further comprising:

selectively distorting an amplitude of the second leading portion so that it effectively corresponds to both amplitude and duration of the first leading portion.

4. The method according to claim 1 wherein the leading portion and the following portion are both on the high side of the alternating power signal.

5. A method for providing power and data to an irrigation device, the method comprising:

modulating data onto an alternating power signal by distorting an amplitude of a first leading portion of selected cycles of the alternating power signal;

permitting effectively a full amplitude of the alternating power signal on a following portion of the selected cycles, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal;

applying the alternating power signal to a multi-wire interface configured to couple with a plurality of irrigation devices; and

permitting communications from any of a plurality of irrigation devices within a time period that generally corresponds with at least a portion of the following portion.

6. A method for providing power and data to an irrigation device, the method comprising:

modulating data onto an alternating power signal by distorting an amplitude of a first leading portion of selected cycles of the alternating power signal;

permitting effectively a full amplitude of the alternating power signal on a following portion of the selected cycles, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal;

applying the alternating power signal to a multi-wire interface configured to couple with a plurality of irrigation devices; and

detecting communications from any of a plurality of irrigation devices within a time period that generally corresponds with at least a portion of the following portion.

7. The method according to claim 6, wherein the leading portion and the following portion occur within a half cycle of the alternating power signal.

8. A method for providing power and data to an irrigation device, the method comprising:

modulating data onto an alternating power signal by distorting an amplitude of a first leading portion of selected cycles of the alternating power signal;

permitting effectively a full amplitude of the alternating power signal on a following portion of the selected cycles, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal;

applying the alternating power signal to a multi-wire interface configured to couple with a plurality of irrigation devices; and

assigning a time period that generally corresponds to the following portion to permit communications from any of a plurality of irrigation devices.

9. A method for providing power and data to an irrigation device, the method comprising:

modulating data onto an alternating power signal by distorting an amplitude of a first leading portion of selected cycles of the alternating power signal;

permitting effectively a full amplitude of the alternating power signal on a following portion of the selected cycles, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal; and

applying the alternating power signal to a multi-wire interface configured to couple with a plurality of irrigation devices;

wherein the leading portion comprises effectively a full quarter of a cycle of the alternating power signal.

10. A method for providing power and data to an irrigation device, the method comprising:

modulating data onto an alternating power signal by distorting an amplitude of a first leading portion of selected cycles of the alternating power signal;

permitting effectively a full amplitude of the alternating power signal on a following portion of the selected cycles, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal; and

applying the alternating power signal to a multi-wire interface configured to couple with a plurality of irrigation devices;

wherein the following portion comprises effectively a full quarter of a cycle of the alternating power signal.

11. A method for use in an irrigation system, the method comprising:

receiving an alternating power signal comprising cycles each having a first leading portion and a following portion, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal;

demodulating data represented by the alternating power signal based upon whether the first leading portion of a cycle of the alternating power signal has an amplitude that is distorted and where the following portion has an amplitude that is undistorted; and

communicating to a source providing the alternating power signal during the following portion of a cycle of the alternating power signal.

12. The method according to claim 11, wherein the communicating occurs during a following portion of a cycle which consecutively follows the first leading portion.

13. The method according to claim 11, wherein the communicating occurs during a following portion of a cycle that does not consecutively follow the first leading portion.

14. The method according to claim 11, wherein the communicating comprises:

selectively shunting a power line used for the receiving of the alternating power signal through a resistor during the following portion of the cycle of the alternating power signal to provide current feedback to effect communications.

15. The method according to claim 11, further comprising:

deriving power from the alternating power signal to charge an energy reserve associated with each of a plurality of irrigation devices.

16. A method for use in an irrigation system, the method comprising:

receiving an alternating power signal comprising cycles each having a first leading portion and a following portion, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal;

demodulating data represented by the alternating power signal based upon whether the first leading portion of a cycle of the alternating power signal has an amplitude that is distorted and where the following portion has an amplitude that is undistorted; and

deriving power from the alternating power signal from a side of the cycle that is opposite to a side of the cycle of the first leading portion and the following portion.

17. A method for use in an irrigation system, the method comprising:

receiving an alternating power signal comprising cycles each having a first leading portion and a following portion, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal; and

demodulating data represented by the alternating power signal based upon whether the first leading portion of a cycle of the alternating power signal has an amplitude that is distorted and where the following portion has an amplitude that is undistorted;

wherein the demodulating comprises detecting whether a voltage measurement of the alternating power signal during the first leading portion reaches a threshold.

18. A method for use in an irrigation system, the method comprising:

receiving an alternating power signal comprising cycles each having a first leading portion and a following portion, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal; and

demodulating data represented by the alternating power signal based upon whether the first leading portion of a cycle of the alternating power signal has an amplitude that is distorted and where the following portion has an amplitude that is undistorted;

wherein the demodulating comprises comparing a first voltage measurement of the alternating power signal during the first leading portion to a second voltage measurement of the following portion.

19. A method for use in an irrigation system, the method comprising:

receiving an alternating power signal comprising cycles each having a first leading portion and a following portion, wherein the first leading portion and the following portion are either both on a high side of a cycle or both on a low side of a cycle of the alternating power signal; and

demodulating data represented by the alternating power signal based upon whether the first leading portion of a cycle of the alternating power signal has an amplitude that is distorted and where the following portion has an amplitude that is undistorted;

wherein the demodulating comprises determining a slope of the first leading portion.

20. The method according to claim 19 wherein the determining the slope comprises determining the slope of the first leading portion using a first voltage measurement and a second voltage measurement of the alternating power signal during the first leading portion.

21. A method for use in an irrigation system, the method comprising:

receiving, at an irrigation device, an alternating power signal comprising cycles, where an amplitude of a portion of each cycle is selectively distorted to modulate data on the alternating power signal;

determining a slope of the portion of each cycle; and

demodulating the data based upon the determining the slope;

wherein the determining the slope comprises determining the slope using a first voltage measurement and a second voltage measurement of the alternating power signal during the portion.