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TetherBox Time Synchronisation
Your TetherBox automatically maintains accurate system time through multiple mechanisms, ensuring reliable timestamps even in environments with limited Internet access.
Time Sources
The system uses multiple time sources in order of preference:
- TetherX Cloud NTP servers - Primary time source
- TetherX VPN - Falls back to synchronising via VPN if NTP servers are blocked (e.g. corporate networks with strict firewalls)
- Hardware clock (optional) - We support a range of battery-backed real-time clock modules, recommended for devices without a built-in RTC (e.g. Raspberry Pi) to maintain accurate time during power loss
Tip: Intel and AMD-based TetherBoxes (Pico, Giga) have a built-in RTC on the motherboard powered by a CMOS battery. For Raspberry Pi-based units, we recommend adding a DS1307 RTC module if time persistence during power loss is important for your installation.
Synchronisation Process
At Startup
- If a hardware clock is present and holds valid time, the system uses it as the initial reference
- The system then fetches current time from TetherX Cloud NTP servers
- If successful and a hardware clock is present, it is updated with the correct time
Ongoing Adjustments
- Time is checked every 24 hours when synchronisation is successful
- If synchronisation fails, the system retries every hour until successful
- The hardware clock is updated whenever a more accurate time is obtained from the network
Camera Time Synchronisation
Your TetherBox also keeps connected cameras synchronised. This runs automatically once per day and ensures camera timestamps match the TetherBox.
How It Works
NTP configuration - For cameras that support NTP via ONVIF or native API, the TetherBox configures the camera to use the TetherBox itself as its NTP server. The camera then keeps its own time in sync automatically.
Manual time setting - For cameras that don't support NTP configuration, the TetherBox sets the time directly via ONVIF or native API.
Daily sync - The synchronisation job runs once per day for all cameras, ensuring any drift is corrected.
Tip: Most modern IP cameras support ONVIF NTP configuration. Older or budget cameras may only support manual time setting, which is slightly less accurate but still keeps timestamps within a second or so.
Why This Matters
Accurate camera timestamps are essential for:
- Event accuracy - Events appear at the correct time in your timeline
- Evidence integrity - Footage timestamps are legally reliable
- Multi-camera correlation - Events from different cameras align correctly
- Search and playback - Finding footage at a specific time works as expected
What This Means for Users
- Accurate timestamps - Events, recordings, and audit logs use correct times
- Offline resilience - If the network is temporarily unavailable, the internal clock maintains accuracy until connectivity is restored
- No manual configuration - Time self-corrects automatically
- Camera alignment - Connected cameras are kept in sync with the TetherBox
Troubleshooting
Timestamps appear incorrect:
- Verify network connectivity - the TetherBox needs Internet access for NTP servers
- Check the TetherBox is connected to TetherX (VPN provides fallback time sync)
Camera timestamps don't match:
- Ensure the camera is accessible via ONVIF
- Camera time sync runs once per day - changes may take up to 24 hours
Raspberry Pi time resets after power loss:
- If an RTC module is installed, the battery may need replacing
- If no RTC module is installed, consider adding one for environments with frequent power interruptions
Related Articles
- Automatic Configuration - How TetherBox configures cameras automatically
- How to Enable ONVIF - Enable ONVIF for automatic time synchronisation
- Power Recovery & BIOS Settings - CMOS battery replacement for Intel/AMD units
- Manual Camera Configuration - Manual camera time settings
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