The Slingbox is on all the time. If you need to turn it off you would unplug it but you will then need to redo the setup at the URL setup.slingbox.com.
You will also need to keep the cable box you have it connected to on all the time or the Slingbox will not have the information it needs to transmit to a mobile device.
Have a great day!
Sling Moderation Team