Since you like parts from Maxim now, take a look at the Maxim MAX3160 and friends. They provide transceivers for both RS-232 and RS-485 protocols, allowing the protocol to be chosen at run time by driving a logic level input.
We are using the MAX3161 in a couple of projects which provide only a three contact terminal strip for field wiring the serial cable (Rx
/A+
, Tx
/B-
, Gnd
). If the port is incorrectly configured the device is still safe because, unlike most RS-422 receivers, it tolerates the full range of RS-232 voltages on the pins regardless of which protocol is currently selected.
This part is a little more expensive than a pair of individual protocol drivers, but makes up for that in saved board area and saved complexity.