When was a legionary fortress stationed at Camulodunum?

Camulodunum was never a legionary fortress, it was a colonia. A colonia was a place where discharged Roman soldiers settled and perhaps were given some land to cultivate and earn a living. Camulodunum, was however the principal site in Roman Britain until the Boudiccan revolt of 60/61 AD. Following that, London became the admistrative centre in Britain. Only Deva, Eburacum and Isca (Augusta/Silurum) were legionary fortresses in Britain during the Roman rule.