If more than one constraint set exists, you must designate the active constraint set. The Vivado IDE uses the active constraint set by default when you launch the synthesis or implementation runs or when you open an elaborated, synthesized or implemented design.
To set the active constraint set, select the constraint set in the Sources window, and click Make active from the right-click menu. In the Sources window, the active constraint set appears in bold with the word "(active)" next to it.
Figure 1. Active Constraint Set
