TMS320F280049C: When the slave node is set to send data, CAN cannot receive data for the first time

Shaoxing Ke said:

when the CAN analyzer sends a command to the customer product to request data transmission,

By the above, I presume you are saying a remote frame is transmitted from the CAN analyzer to request data from the 280049. Correct? Also, in the first figure, I presume the first 3 lines are the remote frames  (ID = 06980783) and the 4th line (ID = 69F8003) is the data frame, correct?

Shaoxing Ke said:

In theory, the request will be sent immediately when CAN complete initialization? 

After initialization is complete and the corresponding message object has been updated with the data to be transmitted, yes, the remote frame will be answered immediately.

Shaoxing Ke said:

the CAN_NDAT_21 register status is always 1 when the CAN analyzer data request, do you know that the root cause of the No data received for the first time?

What you are saying is that message object is ready with the data to be transmitted (as evidenced by the corresponding NDAT bit being 1) and yet, the data frame is not transmitted upon the reception of the first remote frame, but only after multiple remote frames are transmitted from the CAN analyzer.

Is this behavior consistent?

Can you try the can_ex9_Remote_Answer.c example from my App.report www.ti.com/lit/sprace5? 

Hi Hareesh,

     yes, your understanding is right, and the situation is as you depicted. and the same situation as below:

https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1060055/tms320f280049-did-not-transmit-dcan-frame-data-successful-at-the-beginning

Please answer the two questions below:

Hareesh Janakiraman said:

Is this behavior consistent?

Can you try the can_ex9_Remote_Answer.c example from my App.report www.ti.com/lit/sprace5? 

Shaoxing,

   The post you are referring to is completely different. I don't think it is connected to this post.

Hareesh Janakiraman said:

Is this behavior consistent?

yes, It can be repeated, behavior consitstent.

Hareesh Janakiraman said:

can_ex9_Remote_Answer.c example

Hi Hareesh,

     The can_ex9_Remote_Answer.c is not show in the C2000 ware 4.0, so where can I find what you said? and If this example runs successfully on the client's module, what can it explain? 

Hareesh Janakiraman said:

a remote frame is transmitted from the CAN analyzer

Hi Hareesh,

    To clarify the description again, both transmitted from the CAN analyzer and receiving are both data frames. Sorry for confusion.

Shaoxing Ke said:

o clarify the description again, both transmitted from the CAN analyzer and receiving are both data frames. Sorry for confusion.

This changes the discussion completely. This is likely to be a software issue, not related to the CAN module itself.

Hi Hareesh,

    The customer closed all interrupts and implemented CAN by polling. Similarly, only the CAN communication program is retained, and the problem still exists. 

Please have customer try can_ex5_simple_receive.c. This is a simple test case that would toggle GPIO65 upon reception. You can copy this program from C:\ti\c2000\C2000Ware_4_00_00_00\driverlib\f2837xd\examples\cpu1\can.