RaspberryPi 4/5 Ethercat Rtelligent ECT60 Synchronization error

 
I have an issue, after running LinuxCNC Raspberry Pi Ethercat with  Rtelligent ECT60 closed loop stepper controller i will gat about roughly half of hour or sometimes less  EtherCAT ERROR 0-0: AL status message 0x001A: "Synchronization error".  I have narrowed down problem that it occurs when raspberry pi ethernet goes down for a moment and then back up.Then the narrowing down part, I have tried with Raspberry Pi5 and couple of Raspberry Pi 4, I have used own build Rt-preempt kernel and all Linuxcnc/Ethercat from sources and now I have downloaded ready made LinuxCNC 2.9.4 Raspberry Pi image for rpi4 and rpi5. I have followed installation instructions from "Ethercat installation from repositories - how to step by step". I have tried with two separate controller boxes that are having Rtelligent ECT60 boards with two CNC machines and test configuration with just raspberry pi, controller and stepper motors. I have used multiple brand new ethernet cables, tried multiple Raspberry Pi power supplies including original one.  I have tried to disable all other possible services like ntpd NetworknaMager touching interface. I can say that I have changed every component in system. Ethercat is direct cable connection from Raspberry Pi to ETC60.

Good ideas what to try next or even workaround ideas.  When searching "macb 1f00100000.ethernet eth0: Link is Down" for rpi5 or similar for rpi4 i got lot of matching posts from raspberry pi forums. Just not help, there is similar theories about reason, bad ethernet cable, bad power supply, bad ethernet switch. I have tried with multiple cables , mutiple power supplies and I don't have switch but direct ethercat.

I least assume that issue is not in Ethercat configuration or Rpi RT-Preempt kernel because all of these are now standard from repo.
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May be I have found least workaround and some glue what's wrong. I tested adding ethernet switch between my Raspberry Pi 5 and ETC60 Ethercat stepper controller. After adding this switch i have not got any synchronization errors or got Raspberry ethernet link up/down causing that error.

Because i have got same error between multiple tested Raspbelly Pi 4 and 5 boards and least three controller boxes having Rtlligent ETC60it cant be just a faulty unit but more common compatibility issue. Least adding switch is workaround fix.

My general experience from Linuxcnc / Ethercat / ECT60 is very positive. First I replaced always failing PC hardware with Raspberry Pi and PIO controlled steppers but I wanted better and Ethercat felt best choice. In beginning i needed to build everything from sources. This joint x motion error / synhcronization error was only unresolved issue and it took long time to find out that it was not caused by other factors like insufficient real time performance.Now when everything works and there is easy installation package i think that it will be my number one option. Next I will try Lichuan Ethercat servo and lets see is do I need switch between Lichuan ethervcat controller or not

Well, I don't have a pi with linuxcnc and only googled a bit.
forums.raspberrypi.com/viewtopic.php?t=362866#p2229969 worth a try I guess if you haven't done so.
 

That one i have already tried but it did not help

I'm not too sure if this may help
github.com/MichaIng/DietPi/issues/6577

The power saving feature shouldn't be kicking whilst there is traffic, but stranger things do happen. And I know the RPi is on a later kernel.
Actually that reminds me I'll have to talk to Rod about Ethercat repos for the new image.

unknown wrote:

I'm not too sure if this may help
github.com/MichaIng/DietPi/issues/6577

The power saving feature shouldn't be kicking whilst there is traffic, but stranger things do happen. And I know the RPi is on a later kernel.
Actually that reminds me I'll have to talk to Rod about Ethercat repos for the new image.

Hmm, that puts the kybosh on the kernel.org docs saying EEE is disabled by default. Always disable it!

I haven’t run my ect60 drive for more than 30 minutes, so I haven’t seen this problem.

I appreciate all your documentation however. I’m also running a pi4b.

When you installed the Ethernet switch, did you maintain the series cabling for all the drives? Put another way, do you have just the pi and the first ect60 connected to the switch?

I wonder if a loop configuration using the Ethernet port on the pi, plus one more usb dongle Ethernet port would also solve the problem.