Assuming I have light switch/push button with only readable state (via pin on Arduino).
Following https://www.mysensors.org/download/serial_api_20#sensor-types ,should I present it via:

present(CHILD_ID, S_BINARY);

?

Later, having binary switch (which should be settable from controller) how it should be presented?

How controller can distinguish between RO button and RW switch?