Syncronization Working Group

🧑🏻‍💻 Working Groups
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Welcome to the openDAQ synchronization working group.

This space is for openDAQ users and contributors to collaborate on improving synchronization within openDAQ. Join us to discuss challenges, share ideas, and shape solutions to enhance the SDK.

Feel free to introduce yourself, ask questions, or jump into discussions—we’re here to support you.

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Agenda for the inaugural meeting on 26. November, 3 p.m. CET. (duration ~ 90 mins)

  1. Welcome and Introductions (10 minutes)
  2. Overview of Synchronization in openDAQ (15 minutes)
  3. Key Challenges in Synchronization (open discussion, 40 minutes)
  4. Next Steps and Future Meetings (10 minutes)
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Summary of the openDAQ Synchronization Working Group Meeting

:date: Date: November 26, 2024
:alarm_clock: Time: 3:00 PM – 4:22 PM (CET)
:busts_in_silhouette: No. of Participants: 9

Hi everyone,

Here’s a summary of our Synchronization Working Group meeting. We covered key topics like PTP implementation, metadata transparency, simulator enhancements, and hardware variability. Below are the detailed notes and action items. Feel free to join the discussion and share your thoughts!

  1. Synchronization Challenges:
  • Accurate time alignment across devices remains a critical issue, especially when devices operate in different domains or experience disconnections.
  • While devices synchronize using PTP (Precision Time Protocol)—the most common synchronization solution—issues arise due to time drifts, time jumps, switching between master clocks, and the need to align frequency and phase with ADCs.
  • Additionally, incorrect or suboptimal implementations of PTP in devices can exacerbate these issues.
  1. openDAQ’s Current Role:
  • openDAQ relies on timestamps provided by the system but does not implement its own PTP daemon.
  • Vendors must configure their systems to ensure compliance with synchronization requirements.
  1. Metadata for Transparency:
  • A proposed solution to mitigate some of the issues mentioned above was to introduce metadata to track synchronization states. Examples include:
    • Last synchronization time.
    • Elapsed time (milliseconds) since the last sync.
    • Accuracy and drift information.
  • Transparent metadata would be used for debugging and understanding data delays or misalignments.
  1. Hardware Variability:
  • Different devices have varying synchronization stabilities, with some drifting significantly over time.
  • There’s a need for clear, actionable guidelines on how hardware vendors should implement synchronization features to ensure compatibility with the openDAQ SDK.
  1. Simulators and Testing:
  • Participants emphasized maintaining and enhancing simulators to test synchronization features effectively.
  • Requests included the ability to simulate low-frequency operations and create complex topologies for testing.

Potential openDAQ Upgrades Discussed:

  • Improve transparency about timestamp accuracy and synchronization state.
  • Provide more examples and documentation on synchronization implementation.
  • Develop hardware-specific guidelines for vendors to ensure openDAQ compatibility, including setup guides for complex synchronization topologies.
  • Maintain and enhance simulators to support synchronization testing and facilitate development.
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@Dusan good summary. I also took an action to provide some input/diagram of how the PTP synchronisation might work in a long term SHM use case.

1 Like
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Great, thank you Andrew!