Is there any way to discover new Cisco devices add to a network?
Here is a link to download the Orion Admin Guide and please look for the chapter3 Discovering and Adding Network Devices.
http://www.solarwinds.com/documentation/Orion/docs/OrionNPMAdministratorGuide.pdf
are you running NPM? if not, then I don't believe so. If yes, then follow Nandish's advice. there is a job in NCM to import from NPM and NPM can do discoveries.
Thanks. Is there any way to make it run on a schedule?
All NCM jobs are run via the scheduler, so yes you can schedule the Node Import job to run on a daily bases if you like.