J1939 Mapp library with NMEA2000 equipment

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1

hello,
i would like to know if the J1939 Mapp library will support NMEA2000 equipment as the protocols are almost identical.
thank you.

2

The first of all, Im not expert for this topic, so I asked community AI:

The J1939 Mapp library is a software resource primarily designed to handle communication over the J1939 protocol, a standard used in automotive and heavy-duty vehicle data communication. NMEA 2000, on the other hand, is a protocol used for marine instrumentation, and it is based on a subset of the J1939 protocol but with specific marine-related message types. Since NMEA 2000 is indeed based on J1939, the J1939 Mapp library might permit communication with NMEA 2000 devices, but it may require additional configuration or conversion logic to properly handle the marine-specific messages. Support would depend on the library’s compatibility with NMEA 2000-specific settings and whether it can correctly interpret the unique PGNs (Parameter Group Numbers) used in marine applications.

if you will not get answer here at community, and you will probably not get because this is something what developer of this library must say. So you will probably need to contact support of your local B&R office.

3

I am also not familiar with NMEA 2000, however if the messages follow the same format as J1939 I think that it’s at least worth a test. The MpJ1939 function blocks allow you to specify specific PGNs to receive and transmit. As long as the PGN exists at the location it’s expecting within the CAN frame, I’d expect the library to pull the data out.

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5

Hi @Ron_Ben_Michel,what is the status of your topic, can you update us?

6

Closed due to long inactivity. Feel free to reopen it if needed.

7

hello dear community,
i would like to update you regarding NMEA2000 support with the J1939 library.
in general it is working the same as J1939 for single PGN’s (up to 8 bytes of data).
i did not test the multi packet feature (up to 1750 byte) which is supposed to be supported by both protocols.
the only problem i am facing now is a feature called “fast packet” which is only supported by the NMEA2000, which means the data up to 233 bytes can be sent frame by frame losing 1 byte from each frame to mark the number of the frame.
i was able to do some parsing on the data and receive the information but the problem is that the NMEA2000 default baud rate 250Kbps, which means that in order to analyze every frame i need to sample the data at least twice the speed, the X90 PLC can go only up to 400us cycle time which also stress out the system.
also sometimes data is sent cyclically in single PGN which also means every frame need to be analyzed.
does anybody know of a smarter way to do it, maybe with the CAN stack or buffer?
thank you.

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