NOTE: If you have a lot of iDracs and want to programmatically set this on all at once, you can either use OpenManage Essentials, or I will post a script or link to one soon to do this.
***NOTE: A newer version has been released and should be used instead of 6.1.1. http://bradsjumpbag.blogspot.com/2016/02/dell-scom-management-pack-62-released.html***
Download the Dell Server Management Pack Suite for Microsoft System Center Operations Manager v6.1.1: http://www.dell.com/support/home/us/en/19/Drivers/DriversDetails?driverId=8F4J0
NOTE: Keep in mind that many of the unit monitors are not enabled by default. http://bradsjumpbag.blogspot.com/2015/07/dell-opsmgr-mp-suite-unit-monitors-for.html