Here is a campgate from Antioch with a few things that makes it special. It has the "death" workshop (http://www.lateromanbronzecoinforum.com/index.php/topic,660.msg1931.html#msg1931), a large plinth or base and circles in the top row.
Constantine I
A.D. 326- 327
18mm 3.6gm
CONSTAN-TINVS AVG; laureate head right.
PROVIDEN-TIAE AVGG; camp gate, two turrets, no doors, star above; • in doorway; Δ-E across fields.
In ex. SMANT
RIC VII Antioch 71
Nice example! It seems we now have two workshops (http://www.lateromanbronzecoinforum.com/index.php/topic,595.msg1674.html#msg1674 (http://www.lateromanbronzecoinforum.com/index.php/topic,595.msg1674.html#msg1674)) where they used circles. Given that both are in Antioch, might it even be the same engraver?
Tjaart
It sure seems probable that it is the same engraver, given how infrequently circles are found.