Which statement best describes time synchronization in NMEA 2000 networks?

• A. Time synchronization is not supported on NMEA 2000 networks.
• B. Time stamps are required on every PGN to ensure accuracy.
• C. Some PGNs include time-related fields or time stamps to synchronize data across devices.
• D. Time synchronization can be achieved only by GPS timing signals.

Answer: (C)

Time synchronization on NMEA 2000 networks is about using time-related fields when they exist rather than assuming every message carries a time stamp. In practice, only some PGNs include time information, such as a time-of-day or a time stamp, which lets data from multiple devices be correlated across the network. This means you can align measurements from different sensors by their embedded timestamps, even though not every PGN provides a time field and the network doesn’t enforce a single, global clock on every message.

GPS timing is one way to provide an accurate reference, but it’s not the only method, nor is it required for all data. Devices can produce and use their own timestamps when a PGN supports it, or rely on an external timing source if available.