need help with ethercat vs mesa

timo wrote:

Just a general question. Does a mixed system work? Put the basics on the Mesa card and, if needed, extend with Ethercat?

Makes no sense to me, a bit like being half pregnant. But each half would need their own NIC. There are plenty of Ethercat IO modles and its easy to write the XML they need. The one that is costly with limited options (eg. Beckhoff) is an encoder for spindle. 

I also heard about mesa-ethercat combo but it sounds complex with no real benefit. Something you try just because you can I feel. It would probably make sense for me to see what kind of modules I need for ethercat and look how much thats going to cost. 
I need 4 servos, 60 € more than the other servos for all 4, dont know if sto makes sense for me, that would be another ~ 60 € ish. 
I already have a pilz safety relais, how do I tie that into the system with sto?

Im using 8 endsensors and possibly multiple tool sensors in the future,  so I would go for 16 i/o right now and add more later if needed.

VFD would be controlled by a 10v analog output ~50 €

In turn I could sell my mesa, dont know how much I would get tho. Sadly I cant send it back anymore, at least I think so.