[Elecraft] K3, KPA500, StepIRR, Navigator, PC cabling

[James Meade]

What cabling and settings are needed to connect a Windows 7 Pro computer  
to the K3, a SteppIRR antenna controller and a U.S. Navigator so they all  
talk to each other?  I'm running an RS232 cable from the PC to the K3, the  
aux cable from the K3 to the KPA500, and a Y RS232 cable from the K3 with  
one leg to the Navigator and one to the KPA500.  How does the SteppIRR get  
involved?
Thanks,
Jim NO0B