Thought I entered a question yesterday... was very lengthy with my description, but I don't see it here. So, here we go again!
I've 2 S2C modules. Communication works flawlessly when both are connected to XTCU. However, when Coordinator is connected to X-CTU End Module is connected to Arduino Uno there is no communication... I've checked the RX/TX pins using an oscilloscope. I've a ICStation model USB board that the Xbee plugs into. I also have used a Sparkfun model as well (not a USB, but a board with a regulator that also accepts the Xbee). Neither work... all typical Arduino / Xbee code samples fail. What am I missing?