No, sorry.
"S 2" is a 6x2/4 semi-trailer tractor. That means 6 wheels, thereof 2 driven wheels and 4 steered wheels.
"S 2A" is a 6x4/4 semi-trailer tractor. That means 6 wheels, thereof 4 driven wheels and 4 steered wheels.
"S" stands for Sattelzug, german for semi-trailer. "2" stands for two steered axles and "A" for Allrad, all-wheel driven. It is not a real AWD but so they discribed the difference to the one-axle driven version.
Here a picture of a "S 2". If you compare the hubs of the second axles, you see the difference between driven and not driven. S2 same hub at axle one and two. S2A hub at axle two like the front-axle hub of a AWD truck like F 161 AK which I also add.
So, that was the daily truck-technologie training.