The PEARL’s (A1) output is just a control signal, so there is no limit to the number of actuators it can be wired too.
Wiring the PEARL's (A1) to separate supply and return damper actuators:
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.
Wiring the PEARL's (S1) input for position feedback:
Although the PEARL’s (A1) output might be wired to multiple actuators, the (S1) input can only be wired to a single actuator’s position feedback signal. You will want to wire the outdoor damper’s position feedback signal to the PEARL’s (S1) input.
What about an exhaust damper?
Yes, you can wire the PEARL’s (A1) output to the exhaust damper’s actuator as well. The exhaust damper should move in the same direction as the outside damper. In some situations, the exhaust damper is mechanically set to lag behind the outside damper so as to create a slightly positive indoor pressure.