BFS-11/BFS-12 is a module level rapid shutdown device offers fire safety for solar rooftop and building, remainsthe rapid shutdown function period the solar PV system whole working life.
Emergency button switch is required to initiate the rapid shutdown operating, as a trigger place on the ground and easier to reach.
The communication cable on the rapid shutdown device should be connected in series and wire to the button switch.
So the button switch can control the BFS rapid shutdown devices.
A communication that is no cross-talk with the inverter or WIFl source.