Re: How can we invoke a config backup when there is a change in configuration

You probably want to look into RTCD, or Real-Time Change Detection.    Unless you configure it, NCM isn't really "monitoring" for changes, if you have a job scheduled it will catch changes when the job runs.  However, if you want to do it real time, you need to configure this...

http://www.solarwinds.com/documentation/en/flarehelp/ncm/content/cirrusagrtccd.htm