Thanks for the excellent reply as always. Could you give a concrete example of using resonance veil on a device that exists in the physical world? Could you imagine it being used to bypass a keypad by indicating the correct combination was entered, for example?
Let's stick with your maglock example. Technomancer decides to try to use Resonance Veil to convince the maglock that someone has entered the correct code. A few things you need to know first, such as the Intuition of the last person that programmed the maglock. I'd assume this is going to be a person with at least a 4 Intuition. Data Processing is always the same as the Device Rating, which can vary from maglock to maglock. For the purposes of our simulation, let's go with a maglock rating 4. This isn't going to be super-easy, but it won't be incredibly hard either.
First the technomancer chooses the Level, which in this case is going to be a 6. He then rolls Software + Resonance, which let's say is a total dice pool of 11, with a limit of the Level (6). I'm just going to use random.org to come up with the number of hits here. The technomancer rolled really well and got 6 hits! The maglock then rolls it's 8 dice (Intuition 4 + Data Processing 4) and gets only 2 hits. *cue sad trombone sound*
The maglock then rolls a Matrix Perception test, using it's Device Rating in lieu of the Computer skill. In order to see through the deception, the maglock would have to get 4 hits or more. So that's a total of 8 dice ("Computer" 4 + Intuition 4) and gets 3 hits. *cue sad trombone* It was close, but not good enough to break the deception of the Resonance Veil. The technomancer has successfully fooled the maglock into thinking that someone has entered the correct code, then rolls his fading attributes (I use my own advanced technomancer rules to change the fading attributes, by the way) against 5 points of fading damage.