The TwisTorr 84 FS onboard controller is a solid-state frequency converter, which is driven by a single chip microcomputer. It consists of two PCBs, which include power supply and three-phase output, analog and input/output section, microprocessor, and digital section. The power supply, together with the three-phase output, converts the single phase AC mains supply or 24 VDC supply into a three-phase, low voltage, medium frequency output, which is required to power the pump. A remote host computer can operate the controller via the serial connection. Windows-based software is available (optional). The TwisTorr 84 FS onboard controller can be mounted onboard, on the bottom of the TwisTorr 84 FS pumps.