Ethercat random jitter fix

It sounds like you get gravel in the servo motors from time to time.
Or you get click sounds from the motors. It repeats itself with a few or many minutes apart.
The first thing to do is to enable syncToRefClock and enable DC mode for the servos,
this will keep the servo loop in sync with the DC.

What grandixximo is doing here is fixing an effect that despite DC and servo loop are synchronized,
the two loops have been started with an undetermined/unfortunate phase between them.
The gravel sound is there all the time and it doesn't go away until linuxcnc is restarted.

Surprisingly, yesterday Sasha Ittner popped up in the PR log and mentioned he had been working
on a complete redesign of the DC system, eliminating all these problems (don't know details)
grandixximo seems to have reviewed that work and decided to adopt Sasha's work.
grandixximo will have to say himself. And if you don't know, Sasha Ittner is the author of linuxcnc-ethercat
from many (>10) years ago.

Okay, thank you.

I had already thought that the issue had something to do with packet loss when starting LinuxCNC.
However, this seems to occur during operation, which I have not yet experienced. If this work results in ethercat running more stably, I will simply wait until Sascha announces an official patch, which will likely be available via update.
Until then, I will simply stick with refClockSyncCycles="1">.

Better yet, enable synchronization with syncToRefClock="true"
github.com/linuxcnc-ethercat/linuxcnc-et...s.md#master-settings

The refClockSyncCycles is how often to synchronize the clocks between the slaves
which is something different altogether, and doesn't help this problem.

I currently have refClockSyncCycles="-1" which according to the docs you linked above, means its enabled for backwards compatibility. Sadly, I have these mentioned issues where the axis starts clunking randomly (on a random axis) after some time. Its a fresh install from end of january. Does SyncToRefClock still need to be set?

There was a bug with "-1", fixed now but it sounds like you have it.
Use a positive value in refClockSyncCycles and set syncToRefClock="true"
and that should hopefully fix it.

Now as in just recently or in the patch from last year? or reaaally recently
Also, what does the refClockSyncCycles value do and is there any baseline on what to set it at?