Nets, useful topological tools, used to generalize certain concepts that may only be general enough in the context of metric
spaces. In this work we introduce this concept in an $S$-poset, a poset with an action of a posemigroup $S$ on it which
is a very useful structure in computer sciences and interesting for mathematicians, and give the the concept of $S$-net. Using $S$-nets and its convergency we also give some characterizations of separated $S$-posets. Also, introducing the net-closure operators, we investigate the counterparts of topological separation axioms on $S$-posets and study their relation to separated $S$-posets.