The SX does not have any inbuilt circuitry for this purpose, so if you want to go wireless then you need the full fox wireless kit or the ATTX system.
I would recommend the ATTX over the fox as then you can spread your rods about a bit more. The fox unit requires each alarm to be wired to the sender unit, then its wireless to the reciever. The ATTX uses a dongle on each alarm allowing much greater freedom, and no wires whatsoever