Long standing nitelink procedure is NOT to pick up enroute, there are some designated pick up points. These are clearly shown in the timetable
http://www.dublinbus.ie/en/Your-Jour...Timetables/7n/
For 7N, pick ups are
1. Opposite US embassy
2. Blackrock Park (Blackrock village end)
3. Dun Laoghaire (Shopping centre not the train station despite what is said in the timetable)