What do PF and PS in NMEA 2000 PGNs determine?

What do PF and PS in NMEA 2000 PGNs determine?

• A. Message priority and checksum.
• B. Device type and PGN number.
• C. Voltage level and data rate.
• D. Addressing type and data payload length.

Answer: (D)

PF and PS are the two parts of the PGN in NMEA 2000. They determine whether a PGN uses the PDU1 format or the PDU2 format. With PF less than 240, PS holds the destination address, so the message is addressed to a specific device. With PF 240 or higher, PS holds a group function, and the message is broadcast to all devices in that group. This addressing behavior defines how the message is delivered. The particular PGN, identified by PF and PS, also dictates how many data bytes follow in the payload, so the data payload length is set by the PGN’s defined structure.

PF and PS are the two parts of the PGN in NMEA 2000. They determine whether a PGN uses the PDU1 format or the PDU2 format. With PF less than 240, PS holds the destination address, so the message is addressed to a specific device. With PF 240 or higher, PS holds a group function, and the message is broadcast to all devices in that group. This addressing behavior defines how the message is delivered. The particular PGN, identified by PF and PS, also dictates how many data bytes follow in the payload, so the data payload length is set by the PGN’s defined structure.