UJA1169 CAN transceiver erratic behaviour

sambath_kumar_k · ‎07-30-2020

Issue:

Active error is seen on CAN on every other transmission when the baud rate is switched (ex 250kbps to 500kbps).

Other Observations:

Micron controller S32k can transmit and receive on 250k, 500k and 1Mbps baud rates without any issues.

Test Execution details:

Start Communication on CAN at 250k

Change the Baud rate to 500k

Transmit a message from tool to the ECU, ECU sends the same message back on 500k.

ECU transmit fails on every other transmission.

PetrS · ‎08-04-2020

Hi,

why do think it is wrong transceiver behavior? It does just signal translation between CAN bus and MCU. No bitrate setting is done, unless partial networking is used. But you did not mention this.

So once MCU and CAN tool is configured to have the same bitrate, communication is correct.

If different bitrate is set on MCU you see errors detected. This sound reasonable.

Then you tries to correct bitrate on MCU, but still you see error frames on bus. Is this correct understanding?

If yes, how the bitrate is changed, is the respective registers really modified?

BR, Petr