ganutenator
Lifetime Supporting Member
One quick word of warning on brendan's suggestion - the 1769-L16ER processor can only have 6 expansion cards, at 8 I/O points each (plus the 16DI/16DO onboard). That doesn't leave you a lot of breathing room for anything more than a very small machine.
Of course, you can always add a point I/O rack if you need more - but the other limitation of the L16 is 4 ethernet/IP nodes. Three VFD's on ethernet and one for an I/O rack leaves you hard up against the wall for expansion.
I'd probably go for an L18 at the very least, just to give yourself a liiiiitle more breathing room.
Other than that - I agree with brendan. Ethernet/IP is probably the way to go, but definitely speak to an ABB rep about the application if you're using ABB drives.
(disclaimer: I'm an insolent young whippersnapper and I love me some ethernet. I don't think I've ever recommended ControlNet or DeviceNet for a new application, and I'm not likely to start now )
I have some horror stories using DeviceNet back in the 90's.