PTP issue

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Xavier
1

I’m testing a PTP with my device using the Jetson AGX Xavier developer kit.
The connection configuration is Jetson(master) ↔ switching hub(ptp support) ↔ my device, and ptp command is “sudo ptp4l -i eth0 -m & sudo phc2sys -w -s eth0 -O 0 -m”.

If I connect only one my device, it works well without any problem(timestamp sync is well).
However, when I connect two my device, timestamp synchronization is not working well.
Nothing is printed in the terminal.
What’s the problem??

in the picture is the timestamp print by my device, and is the timestamp print by the other one my device.

Jetson has ubuntu 20.04.6 version.

(If I replace Jetson with a PC, there will be no problem. In other words, if I configure PC ↔ switching hub ↔ my device 2EA and do a ptp4l, timestamp synchronization works well. Ubuntu 20.04.6 is installed on the PC. )

capture
capture743×983 134 KB

When I checked the ptp protocol through the pcap data saved by tcpdump, there was no difference.
I think the code that handles PTP in Jetson is not processing properly when two delay requests come in. Is that correct?

3

Hi,
We would suggest connect to single device. It may not work properly if multiple devices are connected.

5

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.