MIMX RT1176-EVKB Genavb/TSN synchronization failed.

[ZhaoXingLi]

When I was testing GPTP using two MIMXRT1176-EVKB boards, I found that the two development boards could not synchronize successfully. I needed to add compensation to the ports, but after compensation, the synchronization was successful. I was able to distinguish between master and slave. Then, I tested the AS accuracy through the PPS signal and found that the error was about 18us. What debugging methods can I use to reduce the link latency?

[Gavin_Jia · Accepted solution]

Hi @ZhaoXingLi ,

Thanks for your interest in NXP MIMXRT series!

I'm not entirely sure how you arrived at the compensation value of -36.5 us, but it seems a bit too high. Have you tried setting both rxDelayCompensation and txDelayCompensation at the same time?

Also, the final 18us error is unusual. Could there be an issue with the connection? Why not try using a different Ethernet cable to check? Thanks!

Best regards,
Gavin

[ZhaoXingLi]

Hi@Gavin_Jia,

thank you for your reply. I apologize, it was my mistake. The 18µs error was because I didn't perform port compensation on the development board and the GPTP synchronization failed during testing. After compensating for txDelayCompensation and rxDelayCompensation, the AS accuracy tested via PPS was around 20ns. I would like to ask if this error range is normal? Also, without port compensation and setting GPTP synchronization to fail, I can't distinguish between master and slave. Are there any other solutions for this? Looking forward to your reply, thank you.