Wiring Protocol

What is the wiring protocol for the thermostats? I need to know how to prewire for them.

The ecobee thermostat comes in 2 parts. You have the thermostat and the Equipment Interface.  You will require to run 4 wires from the Equipment Interface up to the Thermostat. You will then need to run x number of wires from the furnace control board to the Equipment Interface depending on what kind of configuration you have. If you can let us know what type of HVAC unit you have with the number of stages, cooling, and any accessories,(ie. Y, W, R, G, etc).