Stop, PLEASE stop.

There is no RS232 similarity, concurrence, interface or other such in RS-485.

RS-485 is a different standard created for multidrop using differential signalling.

The BB devices work quite well but DO NOT create true 485, they depend on timing to do the transmit enable and that is NOT how 485 is intended to work.

If you want to discuss 485, do so, but keep 232 out of the discussion

Erik