LENs range from 1-20.

LENs range from 1-20.

• A. 50-100
• B. 1-20
• C. 0-255
• D. 1-255

Answer: (B)

LEN represents how many data bytes are present in that NMEA 2000 message frame. In practice, the standard constrains this per frame to a maximum of 20 bytes, so the valid range is from 1 to 20. If more data is needed, the message is transmitted using the transport protocol across multiple frames, but each frame’s LEN stays within that 1–20 range. The other options suggest lengths outside the per-frame limit or zero data, which aren’t used for a data-bearing frame, so they aren’t valid.

LEN represents how many data bytes are present in that NMEA 2000 message frame. In practice, the standard constrains this per frame to a maximum of 20 bytes, so the valid range is from 1 to 20. If more data is needed, the message is transmitted using the transport protocol across multiple frames, but each frame’s LEN stays within that 1–20 range. The other options suggest lengths outside the per-frame limit or zero data, which aren’t used for a data-bearing frame, so they aren’t valid.