FEV offers a unit that allows the autonomous control of various emissions-control systems, such as NOx adsorber catalyst-diesel particulate filter (DPF) or selective catalytic reduction-DPF systems. The stand-alone solution requires minimal interface to the engine; typically engine speed and load are required, and air mass flow is desired. The unit also is hardware-independent and is suitable for various applications including PM and NOx control retrofits. Interfacing with the engine-management system, CAN-based actuators, or analog/pulse-width-modulation signals permits closed-loop feedback control of the emissions-control system. Features include a flexible design, and aftertreatment systems require calibration adjustments without software modifications.