Your piece has been placed in battery.
A note on nomenclature: A single piece (cannon) and everything that supports it (crew, limbers, caisson, etc.) is a detachment, commanded by a Sergeant. Two pieces and everything that supports them is a section, commanded by a First Lieutenant. Three pieces and everything that supports them is a half battery, commanded by a Captain. Four to six pieces and everything that supports them is a battery, also commanded by a Captain.
Give the commands to get your gun to fire. You are the Chief of Piece.