The PEARL’s (A1) output can be wired to control the positions of the supply and return actuators. You will want to verify that the outdoor damper moves in the opposite direction of the return damper. For example, if the outdoor dampers are 100% open at 10 Vdc, then the return damper should be 0% open at 10 Vdc.
Note: You will also need to wire the PEARL’s common (C) to the both the common wires for the outdoor and return actuators. Common is used as the refence voltage.