The rapid frequency nadion-pulse cannon uses a rotating pulse frequency; each shot is actually millions of separate pulses, each at a separate nutation. The shots cause a defender's shields to modulate into a resonant harmonic field, which overloads the shield generators. These cannons were first proposed by Starfleet in 2366 as a defense against the Borg. Two prototypes were built, but the cannons were deemed too complex for rapid and widespread deployment. Although the firebases were staffed by forty-five personnel, each gun only had a handful of maintenance technicians on duty at any time.