Yeah, my characters power is Technomancy, so he can seize control of opponents technology or learn what it can do, in a process of > basic function/very close proximity effect (which is how he blocks its ability to sense his internals.) > Greater function > Minor control > Complete knowledge > Complete control.

And no, being surrounded by technology isn't really going to be an obstacle to a powerful Technomancer. You wouldn't even expect a hydromancer to have difficulty seperating out one section of water from another, because they need an innate knowledge of the 'element' they manipulate. Technology is very individual and varied, so your own signature would be very visible to him because its so easy to separate. 

That's just the fairest way to put what I essentially said was taking control of technology into a tier system, the first tier will be accessed in my first post (where I'll also explain how he's able to block the scanning.) I'm asking what degree my character can sense your tech (or what defenses it has from his Technomancy.)