Installtion for the Expansion will be similar to the Wall Plate installation for the Controller. The same steps should be followed for wiring of zones as well as the Common wire.
Run corresponding wires to any needed zones 9 through 16. Be sure to also connect the ACommon [C] wire.
Also, connect the rain or flow sensor if desired at this time.
Install by connecting the Expansion Plate to the Wall Plate using the snap-on legs fixed to the back.
Attach the Skydrop Controller face-plate to the Expansion using the snap-on legs.
Once the screen powers up, a prompt should appear requiring you to input the necessary information for the newly added zones.