Abstract: A fluid flow assembly controls fluids passing through a secondary or communication line of a manifold. The manifold includes at least one output port connected in fluid communication with the secondary line. A fluid supply is connected to a fill valve controlled by an electronic feedback control. An exhaust valve is also controlled by the electronic feedback control. Together, the fill and exhaust valves regulate the pressure of the fluid flow through the secondary line and the valves associated with each of the output ports.