Isolated system data communication

• US 9,768,945 B2
• Filed: 03/04/2013
• Issued: 09/19/2017
• Est. Priority Date: 04/23/2012
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Mueck, Michael, Getzin, Lawrence
• Primary Examiner(s): WANG, TED M
• Application Number:
  US13/784,508
• Publication Number:
  US 20130279611A1
• Time in Patent Office: 1,660 Days
• Field of Search: 375257, 375259
• CPC Class Codes: G08C 25/00 Arrangements for preventing or correcting errors; Monitoring arrangements
• CPC Class Codes: H01F 19/08 Transformers having magnetic bias, e.g. for handling pulses
• CPC Class Codes: H04L 25/0264 Arrangements for coupling to transmission lines duplexing arrangements H04L5/14; line equalisers, line build-out devices H04L25/03878
• CPC Class Codes: H04L 7/0016 correction of synchronization errors
• CPC Class Codes: H04Q 2209/823 where the data is sent when the measured values exceed a threshold, e.g. sending an alarm
• CPC Class Codes: H04Q 2209/86 Performing a diagnostic of the sensing device
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

Embodiments of the present invention may provide a system with a first and second circuit system separated by an electrical isolation barrier but provided in communication by at least one isolator device that bridges the isolation barrier. The first circuit system may include a communication system to transmit data across a common isolator device as a series of pulses, and the second circuit system may receive the series of pulses corresponding to the data. The second circuit system may include a detector coupled to the common isolator device to detect the received pulses, a oneshot to frame the received pulse(s), and a controller to reconstruct the data based on accumulated framed pulse(s). Therefore, noise induced spurious pulses outside the oneshot intervals may be ignored by the second circuit system providing improved noise immunity.

Claims

1. A system, comprising:

a first circuit system;

a second circuit system; and

an isolator device coupling the first circuit system and the second circuit system,

wherein the first circuit system comprises a communication system configured to transmit across the isolator device a series of multiple pulses representing both data and a clock edge,

wherein at least one pulse of the series of pulses represents the clock edge and at least one other pulse of the series of pulses represents the data; and

wherein the second circuit system is configured to receive the series of pulses, and comprises;

a oneshot configured to frame the series of pulses, and

a controller coupled to the oneshot, configured to reconstruct the data and the clock edge based on pulses framed by the oneshot.

2. The system of claim 1, wherein the controller is configured to trigger the oneshot to start a oneshot interval, and wherein the controller is configured to reconstruct the data based on a number of received pulses during the oneshot interval.

3. The system of claim 2, wherein subsequent pulses received by the second circuit system during the oneshot interval extend the oneshot interval duration to frame a variable number of pulses.

4. The system of claim 1, wherein a first pulse received by the second circuit system triggers the oneshot to start a oneshot interval.

5. The system of claim 4, wherein subsequent pulses received during the oneshot interval extend the oneshot interval duration to frame a variable number of pulses.

6. The system of claim 1, further comprising a detector coupled to the isolator device to detect pulses received from the first circuit system, wherein the controller is configured to toggle a clock signal based on a first pulse detection by the detector.

7. The system of claim 6, wherein the controller is configured to subsequently confirm validity of a previous clock signal toggle based on the pulses framed by the oneshot and, if an error is detected, correct the error at a next clock edge.

8. The system of claim 1, wherein operation of the second circuit system is synchronized to a reconstructed clock signal obtained from reconstruction of the clock edge.

9. The system of claim 8, wherein the second circuit system further comprises a transmission system to transmit data.

10. The system of claim 9, wherein transmissions by the transmission system are synchronized to the reconstructed clock signal.

11. A method of communicating across an isolation barrier, comprising:

receiving, by a receiver, one or more pulses across an isolator device;

framing the one or more pulses in a oneshot interval, wherein framing of only a single pulse in the oneshot interval indicates a rising or falling clock edge toggle and framing of multiple pulses in the oneshot interval indicates the other of the rising or falling clock edge toggle; and

reconstructing, by a controller, clock edge information based on a number of pulses framed in the oneshot interval.

12. The method of claim 11, wherein a first pulse of the one or more pulses triggers the oneshot interval to start.

13. The method of claim 11, wherein the oneshot interval is triggered to start prior to receiving a first pulse of the one or more pulses.

14. The method of claim 11, wherein framing the one or more pulses comprises extending the oneshot interval to frame a subsequent pulse received within a threshold duration of a preceding pulse.

15. The method of claim 11, wherein greater than two pulses in the oneshot interval indicates additional data.

16. The method of claim 11, comprising reconstructing multibit data including the clock edge information.

17. A method, comprising:

receiving, by a receiver, a first pulse across an isolation barrier;

framing the received first pulse in a oneshot interval;

accumulating a packet of one or more pulses including the received first pulse during the oneshot interval;

toggling a clock signal based on receiving the first pulse;

confirming, by a controller, the clock signal toggling based on the one or more pulses accumulated in the packet; and

if an error is detected, correcting, by the controller, the error at a next packet.

18. The method of claim 17, wherein correcting comprises not toggling the clock signal at the next packet.

19. The method of claim 17, wherein framing the received first pulse in a oneshot interval comprises using a variable duration oneshot interval.