its been a long time since i looked at the specification. i used to think that 422 was the electrical specification and 485 was the signalling standard but recent application notes by maxim and others have led me to conclude that 422 tends to be single pair half-duplex applications (whether multidrop or not) and 485 was dual pair full-duplex applications (whether multidrop or not).

obviously i was too lazy to confirm anything in the actual specification. :)

duh