Ethercat random jitter fix

I’m following this thread closely.But I can’t quite picture how the problem manifests itself.Could someone make a video?

I don't think a hardware master could be used with Linuxcnc in the present implementation of Ethercat. Choose this option carefully as it might require replatforming.

@papagno-source
Would love to get access to the actual machine, there were no jumps on the test rig even moving windows.

@andrax
Videos have been posted somewhere in the thread already I think, not everyone gets the same thing, some motors do a small click, some grind, like vibrate making a grinding noise, this is during motion.

That sounds like the noise produced when synchronization is lost during motion. My solution was to change the parameters to `refClockSyncCycles="-1" sync0Cycle="*2"`. After making this adjustment, I no longer experienced any synchronization loss. I am using an Inovance SV660N drive. You can also add the following line to the XML configuration to monitor the number of synchronization loss events: `<pdoEntry idx="200e" subIdx="19" bitLen="16" halPin="SyncLossCount" halType="s32" />`.


The entry `<pdoEntry idx="200e" subIdx="19" bitLen="16" halPin="SyncLossCount" halType="s32" />` is effective only for Inovance SV series drives; it cannot be used with other drive models.

What does it mean to set sync0 Cycle="*2"?
Should it be set for every drive?

I think that with a value of 2, instead of the default 1, the drive updates the PDOs after two master cycles. If so, I don't know if this is correct for machines that need to interpolate; it would be better to be faster.

It would just be a way to avoid the problem we're trying to solve.

Quite a few people have used 500 Hz servo thread instead of normal 1000 Hz on Raspberry Pi etc so I wonder how much of a difference it really makes? Ethercat would still be doing its thing internally. You'd have to test.