Is EtherCAT becoming the defacto standard for servo amplifier serial communication? Are the commands likely to be PWM, Phase command current or position? Aor all of the above?
My company makes motion controllers. We do more control over Ethernet/IP because there are more AB controllers out there BUT I do like EtherCat and we plan on supporting EtherCat. EtherCat has much less overhead than EtherNet/IP or ProfiNet. However standard EtherCat uses Can Open packets that are very small and therefore limited.
Usually the master downloads position the motion controller uses to construct a polynomial and then do fine interpolation between the master position. The motion controller can compute a fine position and velocity for each time between the master position. This method works well enough but there are flaws in this method if you want to get picky.