This coin is not in RIC with workshop S in left field.
Diocletian
A.D. 290- 292
23mm 3.3g
IMP C VAL DIOCLETIANVS AVG; radiate and cuirassed bust right.
IOVI CONSERVAT; Jupiter standing left, leaning on sceptre and holding thunderbolt, at foot, eagle, in background, two ensigns; S in left field.
In ex. XXIT
RIC Vii Ticinum 228