PEAK-System Forum

I now repeated the test with a new test setup, i.e. different motor board, different cable (without the T-connection) and got similar results, i.e. the settings with sampling point around 0.667 work well (at least in the tests I am doing) while the ones with 0.867 are failing.
It was also confirmed ...

Yes, there are termination resistors on the PC and motor board ends, not at the PCAN-USB.
The T connection is around 80 cm.

I think I do have exact information about the motor boards bit rate, as I have to configure it myself in the firmware. The settings I am currently using on the motor board are


clock = 45 MHz (this I cannot change)
BRP = 3
Prop Seg + Phase Seg1 = 12
Phase Seg 2 = 2
SJW = 2


If my ...

Hello,

It's been a while (I was on vacation and busy with other projects) but unfortunately this is still not fully resolved.

I haven't decided on the final configuration for the driver yet but currently I'm using


CANFD_CTL_IRQ_CL_DEF 1
CANFD_CTL_IRQ_TL_DEF 5


which seems to be okay for the ...

Okay, I will play around with this and let you know which values I end up with.

Thank you so much for your enduring help (and also everyone who might have been involved in the background)! This is something I would pretty sure never have figured out on my own.

Just some clarification question, to ...

It is working!

I just did a quick test so far but it seems that with CANFD_CTL_IRQ_TL_DEF = 5 the delays are mostly gone. There are still some irregularities from time to time but most of the time it is perfect:


(000.001002) can0 RX - - 040 [8] 00 02 EF 89 00 00 00 00
(000.001003) can0 RX ...

So changing the values of these parameters might help?

I am comfortable with building the kernel myself, I anyway do this already for the preempt_rt patch.

I used `candump -t d` with a filter to only show a specific frames that is sent from the motor board with 1 kHz.
Using the classic PCAN cards (i.e. without FD) the output looked like this:

(000.001032) can5 040 [8] 00 00 E6 F0 00 00 00 00
(000.001019) can5 040 [8] 00 00 D7 D1 00 00 00 00
(000 ...

Unfortunately I couldn't find explicit examples for this board. However, I did find a calculator for the timing parameters by TI (previously I used a calculator by some third party).
It indeed gives me different parameters compared to what I used before:

BRP 3
Tseg1 9
Tseg2 5
Bit rate 1000
SJW 4 ...

I am sorry for not having responded anymore. I was busy with an other project and only now have time to look into this again.

Unfortunately `candump -e` does not show any error. It looks like there are just no new messages anymore at some point.

I'm afraid I cannot give a definitive answer ...