PID controllers are widely used in the industrial sector due to their good performance and ease of parameter tuning on industrial platforms. However, the temporal performance degradation in non-linear systems that require changes in the setpoint is a notorious drawback. This article proposes an implementation and tuning methodology for a fuzzy controller in a PLC, modifying the scaling factors through a parameter obtained in closed loop. Tests are carried out in an HIL scheme, simulating a non-linear Level system and the online controller in PLC. Using IAE and ITAE performance indexes, a better behavior in reference tracking and disturbance rejection of the fuzzy controller is observed.