The Time Sensitive Networking (TSN) is for real-time communication with hard, non-negotiable time boundaries for end-to-end transmission latencies.
The main use of TSN is for industrial machine controllers, robots etc.
For this purpose all devices in this network need to have a common time reference and therefore, need to synchronize their clocks among each other. Only through synchronized clocks, it is possible for all network devices to operate in unison and execute the required operation at exactly the required point in time.
The time in TSN networks is usually distributed from one central time source directly through the network itself using the IEEE 1588 Precision Time Protocol, which utilizes Ethernet frames to distribute time synchronization information.
Linutronix helped to implement IEEE 1588 PTP on STMP1-OLinuXino-LIME2.
For Uboot changes Olimex Uboot was used as base. The Kernel patch is sent upstream and can be seen on the mailing list
https://lore.kernel.org/linux-devicetree/20210316080644.19809-1-kurt@linutronix.de/
We also apply these patches in our next STMP1 Linux images release.
The results is correctly working PTP:
# ptp4l -H -2 -i eth0 --tx_timestamp_timeout=40 -f /etc/gPTP.cfg -m
|ptp4l[1434.665]: rms 5 max 13 freq -1069 +/- 7 delay 325 +/- 0
|ptp4l[1435.666]: rms 8 max 16 freq -1068 +/- 11 delay 325 +/- 0
|ptp4l[1436.667]: rms 10 max 19 freq -1060 +/- 12 delay 324 +/- 0
|ptp4l[1437.668]: rms 8 max 17 freq -1055 +/- 10 delay 322 +/- 0
|ptp4l[1438.668]: rms 6 max 9 freq -1057 +/- 9 delay 322 +/- 0
olimex 
Recent Comments