You would need to get one of the controllers with that port and also get a command bus cable and a couple of terminators. Create a collective using your start. Setup the controller you got you can connect it to the Start using the command bus and terminators if you do not have a way to power it just make sure and power down the start while connecting things to the command bus. The new controller can get power over the command bus if it does not have an AC plug or power input port. Once the new controller is initially setup with the wifi info check the firmware and if needed update the firmware. once it is updated and connected to the Start using the command bus cable and the terminators have been added and the system powered up select the collective you created with the start and in the left menu select devices and press the + sign in lower right of screen to add the new controller to the collective. A collective acts like one large controller with the some of all inputs and outputs from it's member controllers. Just wait to setup any inputs or outputs on the new controller until it is a member of the collective sine all those would be erased from the controller once you add it to your collective.
Thank you, that's what I went ahead and did, just arrived today. Bit disappointed I didn't notice that when purchasing the "Start", had I noticed I would have went with the Launch. But lesson learned, still loving this controller!
If you are like me you would eventually need more controllers anyway once you find other uses for them. I have 15 controllers in my largest collective. It is about half at the tank and half in the garage at my RODI unit and mixing station. My first one was the X4 starter kit just after they were originally released. I have been adding to it ever since over time.