It looks like this coin is workshop B; which is not listed in RIC...though it might be H- but it sure looks like a B. I will verify when I get it in hand. What is neat, though, is that it has 17 rows on the right side of the doorway and 16 rows on the left; which beats my 15 row Siscia campgate. Also dots in top row and long block over doorway.
Constantius II
A.D. 326- 327
19mm 3.4g
FL IVL CONSTANTIVS NOB C; Laureate, draped and cuirassed bust left.
PROVIDEN-TIAE CAESS; camp gate with two turrets and star between them; • in doorway.
in ex. SMANTB
RIC VII Antioch 74