This is definitely true of Fanuc, but not a lot else. Even the fiber interconnects are open protocols (regardless of how often implemented they are). At the l

This is definitely true of Fanuc, but not a lot else. Even the fiber interconnects are open protocols (regardless of how often implemented they are). At the low end, you have modbus for everything (yes, it sucks latency wise even over tcp, yes, people can't number crap reasonably, etc. It works in the end). Ethernet/IP is not a bad step up (I use it with 0 rockwell components). All my VFD's can be controlled with the same PLC code because of OVDA standards. Ethercat is also fairly nice (and higher end CNC machines often just have everything from I/O to servo's on a single ethercat bus). It's more complicated, but i expect that will change over time. Right now I have no problems connecting my siemens, mitsubishi, etc servos, field i/o, pneumatic valves, etc together over Ethernet/IP. Even lower end PLC's from automationdirect support it just fine. (I've done Ethercat a few times as well, it's just harder to deal with on the software side ATM unless you go with beckhoff stuff)