Studio 2011 SDK and License Manager

I am using the Trados Studio 2011 SDK where an external program calls the API.  In order for the function to work, Studio must be connected to the License Manager and is using at least one Concurrent User license.  I am looking for information about how licenses are consumed when used in this fashion.  Does the License Manager release the license after a certain period of time?  How can I tell how many licenses are being used?