Time Dissemination During Reference Outages

When a device loses its external reference (for example GNSS, PTP, upstream NTP, or timecode), it enters holdover and continues running on its internal oscillator. Depending on configuration, the device may also stop serving time outputs during the outage.

During holdover, time accuracy can slowly drift. To prevent distributing time that may no longer meet accuracy requirements, many devices are configured to stop serving NTP, IRIG, or SMPTE outputs when the reference is lost. This behavior is expected and intentional.

If your application requires time to continue being served during reference outages, enable Allow time server during reference outages in WinDiscovery:

WinDiscovery → Device Settings → Output Control

When enabled, the device will continue outputting time (NTP and supported timecode outputs) even when no external reference is present.

The setting Duration time server is allowed controls how long the device continues serving time after reference loss.

• 0 seconds means forever
• Any non-zero value limits dissemination to that many seconds after the reference is lost

For most installations that want continuous time service during outages, set the duration to 0.

• With dissemination enabled, the device serves time based on its internal oscillator during the outage.
• Status may show Unlocked or Holdover even though time is still being served.
• Confirm your application can tolerate holdover accuracy for the expected outage duration.