What is a manufacturer proprietary PGN, and when might it be used?

• A. A PGN reserved for firmware update only.
• B. A PGN assigned for manufacturer-specific data; used when standard PGNs do not cover a particular device’s data needs.
• C. A standard PGN defined in the NMEA 2000 catalog.
• D. A PGN used to identify device class in CAN bus.

Answer: (B)

In NMEA 2000, a PGN (Parameter Group Number) identifies how to interpret a block of data on the bus. Most PGNs come from the standard catalog so devices from different brands can understand them. A manufacturer proprietary PGN is a PGN set aside by a maker for data that isn’t covered by the standard catalog. It lets the device share manufacturer-specific information—like advanced diagnostics, custom parameters, or features unique to that brand—without needing a new standard PGN that everyone must understand.

The important part is interoperability: only equipment and software that know that vendor’s PGN definitions can interpret the data, so it’s not widely interoperable. This approach is used precisely when the standard PGNs don’t fit the device’s data needs. It’s not about firmware updates, and it’s not a generic identifier for device class on the CAN bus.