A footplate post sits on a square or rectangular steel plate (commonly 200x200x10 mm or larger) anchored to an existing concrete slab, hardstand, or pad with cast-in or chemical anchors. Resistance to overturning comes from anchor uplift capacity. The standard pattern is 4 to 6 chemical anchors of M12 to M16 in a square layout.
Footplate posts are the answer when a concrete slab is already poured (driveways, courtyards) and digging a fresh footing would chew up the slab. They also install faster than concreted posts: no formwork, no curing wait, gate operational on the same day.
CAD60 supports footplate posts as a per-post option with an SVG footplate orientation picker that records the bolt-hole pattern in the drawing pack.