CAN FD Remote Frame Response Not Received on S32K (ST05 board)

[Harisha]

Description:
Hello,

I am working on a CAN FD setup where I am using the ST05 board as one node and PeakCAN as the other.

• From ST05, I send a remote frame.

• On PeakCAN, I can see this remote frame in PeakView.

• Then, I manually send a data frame (with the same ID) from PeakCAN as a response.

Problem:
The ST05 board does not receive the data frame response.

Note:

• I am using one message buffer. The buffer is first used to transmit the remote frame, and then it automatically switches to RX mode after sending.

• Remote frame transmission is working fine, but the response data frame is not being received.

Question:

• Is there any restriction on using the same message buffer for sending a remote frame and then receiving the corresponding data frame?

• Do I need to configure a separate RX message buffer for receiving the data frame after the remote frame is sent?

• Or is there some configuration in FlexCAN that I am missing?

Thanks in advance!

[PetrS]

Hi,

In CAN FD, remote frames are not supported at all - the Remote Request Substitution (RRS) is always dominant (0). When configuring TX MB to send CAN FD frames, RTR must be 0, and so there will be no switch to RX MB.
For Classical CAN frame the RTR is valid and switch to RX MB would work on FlexCAN.

BR, Petr