What is a PGN in NMEA 2000?

• A. A physical port on the device.
• B. A Parameter Group Number that defines a data group and its fields.
• C. The device model name.
• D. A checksum value used for error detection.

Answer: (C)

In NMEA 2000, a PGN identifies the data that a message carries. PGN stands for Parameter Group Number, and it defines a data group and its fields, telling receivers what data items are present and how to interpret each one. This labeling lets different devices on the network understand the payload consistently, even if they come from different manufacturers. It’s not about a device’s model name, a physical port, or a checksum—the PGN is all about the content and structure of the data being transmitted. For example, a PGN can indicate that the payload includes engine parameters like rpm and temperatures and specify the units and scaling for those fields.