AKD-1206 vs PCnetwork card / TwinCAT - synchronization/command issue (spikes)

Hello Together,

We have been facing an issue where the command signals are interrupted/spiked (randomly, though more-or-less deterministic).
 

Drive: AKD-1206
Control: natural PC network card
SW: TwinCAT via EtherCAT interface

We tested with different synhron params, but the failure is stable.

We replaced networkCard to a temporary (external) NI-PXI real-time controller:
failure also appears, although with change any timing params we could eliminate the problem,
but PXI not the originally planned tool for application.

Anybody has similar phenomenom recently?

I am pretty sure that a network card should control the drive via Twincat properly.

//might be an option to consultate with an expert from Kollmorgen???

thanks

Endre