osxs-Air:~ osx$ pmset -g assertions
[/FONT][FONT=Menlo]2014-11-30 19:14:28 -0800 [/FONT]
[FONT=Menlo]Assertion status system-wide:[/FONT]
[FONT=Menlo] BackgroundTask 0[/FONT]
[FONT=Menlo] ApplePushServiceTask 0[/FONT]
[FONT=Menlo] UserIsActive 0[/FONT]
[FONT=Menlo] PreventUserIdleDisplaySleep 0[/FONT]
[FONT=Menlo] PreventSystemSleep 0[/FONT]
[FONT=Menlo] ExternalMedia 0[/FONT]
[FONT=Menlo] PreventUserIdleSystemSleep 0[/FONT]
[FONT=Menlo] NetworkClientActive 0[/FONT]
[FONT=Menlo]Kernel Assertions: 0x4=USB[/FONT]
[FONT=Menlo] id=500 level=255 0x4=USB mod=11/30/14, 7:19 PM description=XHC1 owner=GenericUSBXHCI
[/FONT]