BCN Terminal 1 and Terminal 2 are not connected airside, as they're a couple miles apart, and you have to take a shuttle between the two.
According to the airport website, the shuttle runs every 4-7 min during the time you are arriving, and the transfer should take 14 minutes.
You can check the airport website for more details:
http://www.aena.es/en/barcelona-airp...terminals.html