Changing arrow direction on grilles

[AutoCAT95]

How can i change arrow direction on my grilles to make it like the green one?

In grill properities I've got Mechanical-Flow section which contains: "AirArrow_C,D,L,R,U" checkboxes. On that view onlny "AirArrow_C" makes that arrow appear and disappear, but doesn't change direction. Is it familly issue?

[Anonymous]

Nest a Generic Annotation family within the Grille. Create Parameters inside of the Annotation Family that represent the different flow configurations.