Maintaining a shared timeline across your neural data acquisition systems, I/O devices, and subject video is critical to the success of your experiments. But the technical difficulty of precise time synchronization increases with research complexity. In this TechTip, we describe our solutions to this challenge as we prioritize:
- Future-proofing researchers by ensuring broad input source compatibility
- Long-term reliability, providing years of quality recordings
- Universal standard adoption to maximize industry support
Core Concept of Time Sync:
Time synchronization across simultaneous recordings requires three elements: a single master clock distributing time data, input devices capable of reading/writing time to recorded data, and a resilient network allowing these devices to communicate without error.
Default Time Sync using Cheetah / Digital Lynx SX:
Our acquisition systems use the system clock of the computer running Cheetah software as master clock for time synchronization, giving researchers intuitive control of time settings. By default, the Digital Lynx SX acquisition system and Cheetah DAS synchronize with each other to provide microsecond accuracy in UNIX time format. This synchronization extends to the TTL inputs of the Digital Lynx chassis, allowing accurately-timed inputs from a variety of additional TTL output sources as needed by the researcher.
FreeLynx / LabLynx Wireless Systems:
To standardize time settings and ensure accuracy over wireless network connections, we utilize the industry-leading software Domain Time II from Greyware. This software runs in the background on the Cheetah acquisition computer and serves clock data to FreeLynx and LabLynx through the wireless router connection using NTP (Network Time Protocol). This is sufficient for synchronizing a single Cheetah + FreeLynx / LabLynx acquisition system and any peripheral I/O devices connected to the Cheetah computer’s Digital I/O ports, including analog video cameras.
Multiple Systems & GigE Vision Video:
Beginning in Cheetah 6.4.1, we support PTP (Precision Time Protocol, IEEE 1588). This more stringent standard enables highly accurate synchronization across multiple data inputs including GigE Vision digital video, multiple FreeLynx or LabLynx wireless acquisition systems, multiple Digital Lynx SX systems, and a wide variety of additional inputs. Precision across all inputs is maintained by a dedicated timing device.
Additional Best Practices:
As with any complex and sensitive system, controlling environmental factors can be essential to successful results. We recommend installing sufficient battery backup power supply (UPS) appropriate to your device power needs and experiment duration. Selecting a UPS with power conditioning capability may also improve device reliability and longevity, especially when local acquisition device plug power is on a shared circuit.
On the acquisition computer, be sure to disable the following Windows system settings that may cause timing conflicts:
- Set Time Automatically
- Set Time Zone Automatically
- Adjust for Daylight Saving Time Automatically
Be sure to check Cheetah software’s Clock Status indicator (in the Acquisition System Status dialog) to confirm sync status of connected devices before starting recordings.
Have any questions? For more on acquisition synchronization, integrating third-party inputs, or to discuss your next research project, contact us!
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