Interfacing J1939 with PCAN USB - Other Truck

[Meme002]

Hello,


I gave up on the other truck I was testing since it had J 1708. I found an another truck which has J 1939 communication protocol. I started checking the diagnostic port if its working or not. The results are shown below.


Debug Conditions:


Voltage between Can H and Ground is 2.7 Volts


Voltage between Can L and ground is 2.7 Volts


Resistance between Can H and Can L is 63 Ohms


Since the above conditions are optimal based on the literature. I connected CAN Fd pro with J 1939 adapter.


Using Vector Can I tried to listen to Can Frames when the engine is on.

1. I selected All types of frames (standard, extended, can bus load, error etc..)

2. Can Bus load was 40% so looks like the hardware is detecting.

3. Errors frames are the only one that keeps incrementing. All other frames were zero or null.

Is there a reason why cannot I listen to any standard message frames.

Please, let me know whats my next step.



Thanks,

Meme

[M.Maidhof]

Hi,

please start PCAN-View and configure it to 250k bitrate and extended frames, to be able to see CAN messages of a J1939 CAN bus system. (J1939 always uses 29bit extended IDs)

regards

Michael

[Meme002]

Thank you its working now. I have a general question, what happens the CAN ID in the dbc file doesn't match with truck can ID.

For example, in truck when I did testing the following can frame is for speed.

Can ID Hex - 0CF00400 to decimal ---> 217056256 ---> PGN is 61444


Can ID in DBC file for decoding Engine speed.

CAN ID Hex - CF004FE to decimal ---> 217056510 - PGN - 61444

PGN matches but CAN ID doesnt match. Does the system throw errors when I try to decode?

Let me know your thoughts.

[M.Maidhof]

Hi,

that is why we offer a J1939 Add-In for PCAN-Explorer 6 which can handle such J1939 specific decoding. PCAN-View is only a raw CAN monitoring tool.

https://www.peak-system.com/PCAN-Explor ... .html?&L=1

https://www.peak-system.com/PE6-J1939-A ... .html?&L=1

regards

Michael