The FT400-Series flow computers are microcontroller-based indicator/transmitters that display flow rate and total and provide output signals. The FT430 and FT450 provides one scaled pulse output while the FT440 has two. The FT430 may be powered by external DC power source or an optional AC power supply. The FT440 is a “two-wire” or “loop-powered” device, meaning that the 4-20 mA output signal doubles as its power supply.