model u91-R1 has 3 encoder inputs, four other inputs (encoders are
inputs) and has six outputs. Costs $450-550. I have one on my cnc
bender and using the dll from unitronics it communicates and updates
the computer. Using a usb-rs232 com adapter configured to port by
cheapass setup file.

Basically I set it up to read a gcode file, dump ten sets of xyz bends
and travel distances in encoder pulses to the plc. THEN you could shut
the laptop down.. or use it as a DRO polling the plc for position.

I had to get creative with the inputs. I'll upload the code so you can
see what is going on later if requested.