Here is the screenshot of leviton 3 way smart switch ( primary and secondary remote switch) wiring diagram.
For non-smart 3 way switch wiring, it is just mechanical connections in the switch which closes and opens path when we turn on and off switch manually. I understand how current flows.
But when it comes to smart 3 way switches, I am trying to understand how communication happens between both switches and how current flows through traveller wires. I am basically trying to understand where smartness comes from.
1) Do smart switches have internal logic circuit ? 2) Can 3 way smart switches be operated if wifi is down - just like manual 3 way switches ? If yes, how does current flows in 4 different states of both switches ( on/on, off/off, on/off and off/on) 3) Wire in the diagram which connects YL/RD is always hot ? 4) Red wire from main switch (on right side) is directly connected with black wire of load. How would this allow lights to be controlled by both switches ?