To create a blind rabbet, you will need to stop the cut in two locations. Use the same bit and same fence setup used for the stopped rabbet.
Make a mark on the board in each of the two locations where you want to stop the rabbet.
Place the end of the board against the fence and pivot the board off the back of the fence.
Start the router and push the board against the bit. The mark on the board should be aligned with the edge of the fence on the outfeed side of the bit.