Do *not* plug the coal-trol into a ethernet network device of any kind.
We're sending low voltage AC up to the thermostat and low voltage DC (analog and digital) back to the controller module. I don't recall what our absolute rated max length of cord is, but 100' is what we recommend as a practical max. Resistive losses as well as phase skewing due to parasitic capacitance are the issues. If our analog control signals get attenuated significantly or are skewed against wall power phase it can result in problems with speed control outputs.