Is there a way to view what the active discovery is doing and how far it has got so far?

If for example, I want to discover everything on the 192.168.0.0/16 range, I get nothing. Nothing is picked up and discovered at all. I have the active discovery interval set to 7200 at the moment.

Also, let's say that the active discovery kicks off, after 7200 seconds when it's meant to kick off again, will the old job be cancelled?

I know the networks that I want to add are there, it's just too much to do manually. I can scan these networks in a few minutes with Nmap and get thousands of hosts back.

Any help appreciated.

Thanks