CAN RTR usage

[Kamil_16]

Hello everyone, I am working on a project related to CAN communication, and I don't have complete knowledge about the RTR Remote and RTR DATA features within CAN. Should I use RTR Remote in a complex system?

[mƎALLEm]

Hello @Kamil_16 and welcome to the ST community,

That's a generic question on CAN protocol not linked to STM32. (https://www.can-cia.org/can-knowledge/can-cc:(

What do you intend to mean by "complex system"?

 

 

[Kamil_16]

First of all, thank you. What I mean by complex system is this: Reading more ADC data, for example, sending and receiving the values of 20 sensor data points. I think this increases the load on the line a little more.

[mƎALLEm]

You need to take care about your bus load. I think better to use a ring buffer where you feed the ADC conversion and read them back for CAN transmission but still didn't understand your question about the link of RTR with that bus load! RTR is used generally for a "heart beat" mechanism purposes (check for a node still alive) but it could be used to request data from another CAN node.

But the request reply is not automatic, you need to do it yourself. When you receive a RTR frame with that ID, you need to reply back with the requested data ..

[Kamil_16]

Understood, thank you.
I now clearly see that RTR is not intended for bus load optimization, but is only a request/heartbeat mechanism, and that the response behavior must be handled by the software.

 

[mƎALLEm]

Hello,

If my previous post answered your original question, please accept it as solution.

Thank you