rs485 and rs422 are common together

rs422 has 2 txd and 2 rxd pins (differental pair, can go for 1000 ft of wire!)

but you can hook txd and rxd together (now 2 wires!!) and get rs485

we use these at work

https://www.amazon.com/Serial-Converter-Adapter-Supports-Windows/dp/B076WVFXN8/ref=asc_df_B076WVFXN8/?tag=hyprod-20&linkCode=df0&hvadid=309776868400&hvpos=&hvnetw=g&hvrand=16735869446171005016&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031349&hvtargid=pla-486428615671&th=1

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and these: https://www.digikey.com/en/products/detail/digilent-inc/410-310/5125352

digilent pmod rs485 boards

note how the DRIVE enable and RX enable work you tie the togeter and attach to the RTS pin

then turn on hw handshake (half way) ie: drive RTS high during tx enabling the driver then back low when done enabling the receiver

its is half duplex comms

we also run another pair of rs485/422 wires for a common heart beat clock,used for time synchronization to all boards. in our case it is a space craft and the common time is the GPS pulse per second signal