Running a Sub-VI and monitoring data that is generated on a higher level VI

Hi All, 

This question must been there before, but I cannot find a suitable answer here on the forums....

I have a 'top-level' VI that does a lot of things. I also have a sub VI that runs a frequency sweep on a piece of equipment. This is done with a for loop. 

Problem: 

I want to monitor/access the data that is generated in the for loop (See attached, the 3 wires within the green circle I want to monitor). 

2 Questions:

How can I access the data on the wires (within the loop) from a higher level VI?
How can I then run this VI in a higher level VI while the higher level VI is continuing and not waiting for the sub-VI to complete?

I tried using a Que but I cannot seem to get that working. 

Any suggestions?

Regards,