slc ser A vrs ser C

Good morning,
I have a question in regards slc input output modules.I ask it here because i could not find anything on AB web site(they don't make it to user friendly for the beginner).
What is the major difference between ser A and ser C as far as compatibility in replacing one with the other.I have a need for a 1746-ow16 SER C but i have in hand a 1746-ow16 SER A.Other then one being an older version (SER A)Would the SER A work in place of the SER C.

Thank you for any help.

The OW16 is a relay output card, so I would suspect that you would not have any problem with different series.

Thank you