RS422 and RS485 using the same drivers

[adamp524]

Hi,

I'd like to know if its possible to use an RS422 driver chip equipped with receiver and driver enables / disables as an RS485 chip?

The reason being is that I would like to be able to switch between the two communications standards while not changing the physical communications link attached to the circuit.

The RS422 driver chip I had in mind was this:
http://www.farnell.com/datasheets/71023.pdf

Anyone have any ideas?

Thanks

 

[Laplace]

As your referenced datasheet shows, an RS422 chip when equipped with tri-state outputs is essentially an RS485. An RS485 chip will work with an RS422 interface, but an RS422 will not work with a full RS485 interface where tri-state outputs are necessary because multiple transmitters are sharing the same wire line. A good RS422/485 reference would be
http://www.bb-elec.com/tech_articles/rs422_485_app_note/table_of_contents.asp