The high confinement mode (H-mode) is a promising route to achieve high performance tokamak operations, as the ones foreseen in ITER and beyond. However, accessing a stable H-mode phase requires that the power across the plasma separatrix, Psep, exceeds a certain power threshold, PLH. Feedback control can be utilized in this context to guide the H-mode entry and exit, and to tailor its evolution throughout the pulse by monitoring fNetLH defined as the ratio of Psep over PLH. Such a controller has been integrated into the JET plasma control system, using the neutral beam power and the gas puffing as actuators. In this work, we document successful Psep/PLH control studies carried out in deuterium and deuterium–tritium plasmas, which pave the way for using this portable controller in ITER and next step fusion devices.