FR 6921 then FR 4545 at Barcelona
Dublin → Barcelona → Porto
Timetable, Barcelona time
21:40FR 6921 from Dublin at the gate
20:40FR 4545 to Porto leaves the gate
23 h apart on the timetable, overnight
FR 4545 leaves 23 h after FR 6921 arrives on the timetable: more than half a day, so not a connection we count.