That may be not quite right. I seem to remember to have seen
digital I/O modules in a catalog page that had pins that
could be individually switched between input and output.
At the moment i can not remember the vendor. I have never
tried them and have no idea how they did it in software. A
possible way would be to define both inputs and outputs and
and configuration word. Anyway it should not matter to OpenPLC
it would all happen in the I/O module.
We've created I/O modules and PLC with individually configurable direction of digital I/O.
We just had configuration word for that.
And I've seen such modules with cofigurable I/O direction in the field from other vendors.