MX53 FlexCAN can not received remote request frame?

[frankchenmh]

Hi, I connected two MX53 boards to perform CAN test. I ran cansend on one board, and candump on the other. For standard or extended frames the test worked fine. But when test remote request frames, the cansend seems OK, but candump didn't receive anything.

The commands are as follows:

Board A:

# cansend can0 -i 25 -r -v

Board B:

# candump

The BSP I used is MX53 Android R10.3.

Any comment is welcome. Thanks!

[alejandrolozan1]

Hi Frank,

I am a neophyte in SocketCAN but after delving into the this, I never found the arguments you use: -i 25 -r -v

I found examples using something like: cansend can0 123#R  to send a remote request.

Have you tried that?

Best Regards,

Alejandro

[frankchenmh]

Hi Alejandro,

Thanks for reply. I think the "-r" argument of cansend indicates the frames to be sent are remote request frames. I just typed "cansend" and got the following usage messages:

root@freescale ~$ cansend

Usage: cansend [<can-interface>] [Options] <can-msg>

<can-msg> can consist of up to 8 bytes given as a space separated list

Options:

-i, --identifier=ID    CAN Identifier (default = 1)

-r  --rtr              send remote request

-e  --extended send extended frame

..........

-h, --help             this help

     --version          print version information and exit

I did further test on this issue. I connected MX53 with CAN analyst and typed "cansend can0 -i 25 -r -v" to send remote request frame from MX53 to analyst. The analyst received the remote request frame suceessfully. I also tried "cansend can0 123#R", the analyst receives the frame too but it indicates it's a normal frame but not remote request.

When I tried to send remote request from analyst to MX53, MX53 received nothing (On MX53 I ran "candump").

So it looks like MX53 has no problem when sending remote request, but has problem for receiving remote request.

Thanks.

[alejandrolozan1]

Hi Frank,

I wonder if you have solved this? Have you checked if the iMX53 ACKs the remote request frame? if so, it might be possible that the problem is with the socket can library.

That would mean that the FlexCAN module is not filtering the frame and it is received in the FIFO or MB.

Regards,

Alejandro