The paper discusses fuzzy controllers based on fuzzy relation equations in the case when fuzzy controller inputs are exact. The Godelian implication and minimum function as $t$-norm are considered. The fuzzy relation equation with sup-t composition results in plausible control and the adjoint equation leads to simple fuzzy control (min-max inference method). The computation of fuzzy relations is not necessary. The relation between fuzzy plausible control and simple fuzzy control is discussed. Control algorithms are compared on a simulation example.