Thank you so much for getting back to me. I did get it sorted - turned out that I had not turned development mode on, on my phone. Did that, and the error messages cleared, and Xcode and the iPhone began to talk to each other. Cheers! (and thanks for taking the time to respond.)

Thank you for your response. I think I am up against a paywall issue. I am just trialing some code, and code developement, and do not have a paid developer account. The messages that Xcode puts out do not mention this, but ask me to add the device manually. Tried to do that, and the account page returned an 'only for paid developers' message. So my takeaway is this: Unless I am a paid up developer, the option to test the app on my iPhone is not available. Is this actually the case? Nowhere in the pages of 'how tos' I have been following is this mentioned. If true, it would be far simpler to just state that, instead of putting up dialogues with 'Communication with Apple failed' messages. If not true, then I am truly stumped. I connected my iPhone as per your links. I actually got Xcode to accept the UUID, and give my phone a ' registered' flag. Yet when I try to sign the certificate to enable syncing the test app with the phone, it gives me the same 'Communication failed...' message. Seriously confused at this point...