Issue with XCP on CAN (F2838x – Simulink External Mode)

Dear MathWorks Team,

I am currently programming a TI F2838x processor using Simulink. For External Mode, I am using XCP on CAN and have selected the CAN-A module.

However, CAN-A is not solely used for XCP communication — I also use it for standard CAN communication with different message IDs. XCP works as expected, and I can monitor variable values via the A2L file without any issues. That said, I have encountered an intermittent issue on the CAN bus: occasionally (approximately every 2 hours), a message appears with the same CAN ID as one of my existing fixed-length (8-byte) messages, but with a different data length.

This behavior should not occur under normal circumstances. I have reviewed my XCP configuration and everything appears to be correctly set up. Additionally, I have ensured that no mailbox number conflicts exist between the XCP configuration and my other CAN messages.

I would appreciate any insights or suggestions as to what might be causing this unexpected behavior. Has anyone encountered a similar issue, or is there any known limitation or configuration detail that I might be overlooking?

Thank you in advance for your support.

[Walter Roberson]

The messages with the different data length: is it a consistent different data length, or is it a random size?

If it is a random size, I would speculate that somehow multiple messages are getting merged together.

[Ahmet]

Hello Walter,

The message length and the CAN ID copied from the CAN messages vary. These values are not always the same.