F28M35H52C: CANOPEN Communication

yaowei wang

Prodigy 101 points

Part Number: F28M35H52C

Hi all,

I have a problem.

When I use sdo read access, I set a variable 'SdoSendNum4' to count the number of replies I should send.

I counted the number of sends and replies as equal to the number of requests read by SDO,

but the actual number of SDO replies received was not equal to the number of sends I counted.

When ul0bjID is equal to 22, it is the SDO reply.

Here I sent 10,000 requests and received only 8,755 responses.But my 'SdoSendNum4' count is 10,000.

Please help me solve this problem,

Thinks.

over 2 years ago

0 yaowei wang over 2 years ago

Prodigy 101 points

Somehow, as I increase my sending interval, the number of replies equals the number of sends.

0 Hareesh Janakiraman over 2 years ago in reply to yaowei wang

TI__Guru* 95315 points

While we are happy to help you with queries concerning our CAN module itself, we regret we are unable to help with queries pertaining to HLPs like CANopen. Please seek help from other online forums dedicated for CANopen support.

0 Angela Zou over 2 years ago in reply to Hareesh Janakiraman

TI__Intellectual 1085 points

Hi Hareesh,

Customer also found there is some issue with CAN module:

Normally, frame loss occurs when the cache is overridden, the busy bit should to be 1,right? But they found the busy bit is never to be 1. Is there any other reason will result in frame loss?

0 Hareesh Janakiraman over 2 years ago in reply to Angela Zou

TI__Guru* 95315 points

No, the BUSY bit is only set when the CPU is trying to access the Message RAM area either for writing the data to be transmitted or for reading the received messages. The BUSY bit gets cleared in about 14 CPU cycles, so it is difficult for code to see it set. If the application is “missing” messages, it is likely the application is not reading the messages fast enough. Please see https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1288845/tms320f28377s-can-slave-cannot-receive-the-specified-id-data

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F28M35H52C: CANOPEN Communication