startup.lua

shutdown_output_side = "top"
shutdown_output = true
shutdown_message = "shutdown"
startup_message = "startup"
rednet_side = "back"

rednet.open(rednet_side)

while true do

    id, message = rednet.receive()

    if message == shutdown_message then

        rs.setOutput(shutdown_output_side, shutdown_output)

    elseif message == startup_message then

        rs.setOutput(shutdown_output_side, bool.reverse(shutdown_output))

    end

end