Okay.

In <Name>Amplitude_Signal</Name>

I was thinking that "Amplitude_Signal" was the attribute.

This is only the "text".

So

child.attribute

should be replaced by :

child.text

returning

{http://www.ni.com/LVData}Name Out
{http://www.ni.com/LVData}NumElts 34
{http://www.ni.com/LVData}DBL 

Sorry for this beginner question, should I keep the post for other beginners?

Cheers