How do I connect and use the RS-485?

How do I connect and use the RS-485?

What does the text “Optional RS485” means in the datasheet for RIO?

Is it possible to handle both 2- wire and 4- wire transmission (half- and full duplex)?

Should I use pin 1 (GND), 3(TTL-TxD) and 23(TTL-RxD) to connect an RS-485 device?

How do I use the RS-485 interface from Raspberry PI to send and receive data? And how do I configure the RS-485 interface, for example baudrate?

I develop my application in Python.

Just found out the hard way the RIO don't support RS 485, its not even optional. So dont' believe the website.