Synchronized clock event report

• US 9,083,503 B2
• Filed: 05/02/2013
• Issued: 07/14/2015
• Est. Priority Date: 05/02/2013
• Status: Active Grant

• Current Assignee: Schweitzer Engineering Laboratories, Incorporated
• Original Assignee: Schweitzer Engineering Laboratories, Incorporated
• Inventors: Sagen, Eric A.
• Primary Examiner(s): Vo, Don N
• Application Number:
  US13/875,953
• Publication Number:
  US 20140328441A1
• Time in Patent Office: 803 Days
• Field of Search: 375/356
• US Class Current: 1/1
• CPC Class Codes: H04J 3/0644 External master-clock
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04J 3/0697 Synchronisation in a packet node
• CPC Class Codes: H04L 7/0079 Receiver details

Abstract

The present application discloses monitoring a plurality of time inputs to detect a defined time event and providing a report of the plurality of time inputs for analysis in response to detecting the defined time event. To create the report, an event monitor records data relating to the plurality of time inputs in a temporary memory for a defined window of time. In response to detecting the defined time event, the event monitor transfers the data recorded in the temporary memory to a persistent memory and continues to record data relating to the plurality of time inputs to the persistent memory for a second defined window of time. The event monitor provides a report of the data relating to the plurality of time inputs stored in the persistent memory for analysis.

Claims

1. A method comprising:

receiving a plurality of time inputs at a time signal distribution device from time sources external to the time distribution device;

monitoring the plurality of time inputs to detect a defined time event from the plurality of time inputs;

periodically recording data relating to the plurality of time inputs in a temporary memory, wherein the data relating to the plurality of time inputs is retained in the temporary memory for a first defined time; and

in response to detecting the defined time event;

transferring the data relating to the plurality of time inputs from the temporary memory to a persistent memory; and

continuing to periodically record data relating to the plurality of time inputs to the persistent memory for a second defined time.

2. The method of claim 1, further comprising providing a report of the data stored in the persistent memory to determine a cause of the defined time event.

3. The method of claim 1, wherein the plurality of time inputs are received using one or more of:

an Inter-Range Instrumentation Group (IRIG) protocol, a global navigational satellite system (GNSS) signal, a radio broadcast, an IEEE 1588 protocol, a network time protocol (NTP), or a simple network time protocol (SNTP).

4. The method of claim 1, wherein a time input of the plurality of time inputs is received from a GNSS signal and the defined time event is a loss of a satellite lock.

5. The method of claim 4, wherein the data relating to a time input received using a GNSS signal includes antenna location, antenna status, signal strength, ephemeris data, and/or diagnostic information.

6. The method of claim 1, wherein periodically storing data relating to the plurality of time inputs comprises storing a snapshot of data relating to the plurality of time inputs at a rate of one snapshot per second.

7. The method of claim 1, further comprising periodically storing data relating to a plurality of system components which receive a time from the time distribution device.

8. The method of claim 1, wherein the defined time event comprises time signal manipulation.

9. A time signal distribution device for receiving and distributing a time signal, comprising:

a plurality of receivers, each configured to receive a time signal of a plurality of time signals external to the time distribution device;

a temporary memory for periodically storing data relating to the plurality of time signals, wherein the temporary memory is configured to retain the data relating to the plurality of time signals for a first defined time;

an event monitor for detecting a defined time event from the plurality of time inputs; and

a persistent memory for storing the data from the temporary memory in response to the event detector detecting the defined event and periodically storing data relating to the plurality of time signals for a second defined time after detecting the defined time event.

10. The time signal distribution device of claim 9, further comprising an event reporting component configured to provide a report of the data stored in the persistent memory to determine a cause of the defined time event.

11. The time signal distribution device of claim 9, wherein the plurality of receivers comprises receivers configured to receive time signals using one or more of:

an Inter-Range Instrumentation Group (IRIG) protocol, a global navigational satellite system (GNSS) signal, a radio broadcast, an IEEE 1588 protocol, a network time protocol (NTP), or a simple network time protocol (SNTP).

12. The time signal distribution device of claim 9, wherein a receiver of the plurality of receivers is a GNSS receiver suitable for receiving a GNSS signal and the defined time event is a loss of a lock on the GNSS signal.

13. The time signal distribution device of claim 12, wherein the data relating to a GNSS time signal stored in the temporary memory includes antenna location, antenna status, signal strength, ephemeris data, and/or diagnostic information.

14. The time signal distribution device of claim 9, wherein periodically storing data relating to the plurality of time signals comprises storing a snapshot of data relating to the plurality of time signals at a rate of one snapshot per second.

15. The time signal distribution device of claim 9, wherein the time distribution device is further configured to periodically store, in the temporary memory, data relating to a plurality of system components which receive a time from the time distribution device and transfer the data relating to the plurality of system components to the persistent memory in response to the defined time event.

16. The time distribution device of claim 9, wherein the defined time event comprises time signal manipulation.

17. The time distribution device of claim 9, wherein the defined time event comprises loss of a time signal of the plurality of time signals.

18. The time distribution device of claim 9, wherein the defined time event comprises acquisition of a time signal.

19. The time distribution device of claim 9, wherein the defined time event comprises use of an alternate time signal.

20. A time signal distribution device for receiving and distributing a time signal, comprising:

a global navigational satellite system (GNSS) receiver suitable for receiving a plurality of external GNSS signals and determining time information from the GNSS signals;

an event monitor configured to collect data relating to the GNSS signals and detect a defined time event from the plurality of external GNSS signals;

a temporary memory for periodically storing the data relating to the GNSS signals, wherein the temporary memory is configured to retain the data relating to the GNSS signals for a first defined time; and

a persistent memory for storing the data from the temporary memory in response to the event detector detecting the defined event and periodically storing data relating to the GNSS signals for a second defined time.