FS6500 CAN BUS off

[witness]

hi, experts Now I am working on a project based on S32k324&FS6500, as for FS6500, we use it as SBC and CAN transceiver. but for CAN bus off testing, only CANH->GND can cause bus off, CANH->CANL and CANL->VCC won't cause CAN bus off. besides, another CAN node of S32K324 which use TJA1043 as tranceiver, the three cases can be able to cause CAN bus off, so I suspect may some FS6500 register have not been set properly, anyone can give me a clue? thanks. 

[TomasVaverka]

Hi Ming,

Please see below about FS6500 capability to detect CANH/CANL shorts to BATT/GND.

BR, Tomas

[witness]

hi, Tomas

Thanks for your reply, I have noticed the information you have mentioned, but currently, except CANH -> GND, for another two case(CANL->VCC, CANH->CANL), SBC CAN TX and RX electrical level keep same, so it seems like the chip can not detect the failure.

[witness · Accepted solution]

Issue fixed, the reason is related to hardware design, there is a limit current resistor near the CANH and CANL of SBC, just remove it.