TMS320F280049C: CAN Problem - F28004x

Hi Nilesh,

Just a couple of things you can check if you have not done it yet:

- Is the transceiver power on?

- Is the CAN bus (CAN_L, CAN_H) properly terminated by 120ohm resistor?

- The F280049C is a 3.3V I/O device,  Ensure that the transceiver accepts 3.3V levels as well.  Some of the transceivers only accept 5V rails.

Regards,

Joseph

Hello Joseph,

     I have looked at all the above aspects and I looked at the CAN_ES Register and found that the ACK Error is present.

      What can be done to overcome it?

Thank you.

Regards,

Nilesh

Hi Nilesh,

ACK error means that there wasn't a node in the CAN bus that got and acknowledged the frame.  Not sure how the PEAK CAN works but does that act as a node that receives the CAN frame (i.e. - sends a dominant bit in the ACK phase) or does it just "sniff" the bus just like a scope does?  Also i missed your initial statement "I have sensed the pulses using oscilloscope, they are fine. ".  Do you mean that the PEAK CAN is not reading the CAN messages?  If this is the case, can you also check if the baud rate F280049C CAN and the PEAK CAN baud rate settings match?

Regards,

Joseph

Hello Joseph,

PCAN acts as a node. The Baud rates are matching too. Do I need to modify the Bit Timing?

Hi Nilesh,

If you are using the routines/examples in C2000Ware, you should not have to modify the bit timing as the functions take care of that provided that you have the correct SYSCLK and baud rate settings.  Maybe also double check that your set up has the correct SYSCLK setting.  If you confirm that the clocking and timing setups are OK, can you aslo capture the CAN frame on the Oscope?  If the message is acknowledged, you should see a a low level pulse after the data and CRC field if you scoped the CAN bus.

Regards,

Joseph