GPS Sync Box

For what length of time will the sync remain valid?

Located inside every power meter is a Real Time Clock (RTC) which accurately keeps tracks of Coordinated Universal Time (UTC) since the last sync took place with a GPS Sync Box.

The RTC is accurate to ±0.432 Second/Day over the entire temperature range from -45°C to +85°C. In other words, the RTC will drift no more than ±0.432 over the course of 24 hours, even if the temperature varies significantly throughout the day.

We have defined it such that a sync will be considered expired if 6 hours or more have elapsed since that sync occurred. This equates to a worse case drift of ±0.108 seconds which closely lines up with the 100Hz High Speed Data sampling period of 0.100 seconds.

How often will the power meter search for a sync?

Searching for an active GPS Sync Box consumes power, so we want to limit the time the power meter spends searching for one. If the power doesn't currently have a valid sync, then it will start search more frequently - more specifically, the power meter will begin a short search (for 5 seconds) every 60 seconds.