when to check the float licence

hi

There are one float testcomplete platform licence and one float Desktop licence and lauch the testcomplete to establish the session,Then I  can use the testcomplete to do the desktop automation tesing.  try to  disconnect the current session by pulling cable to lost the connect with licence management,  the testcomplete can still be used until  closing it , I 'd like to know when the testcomplete to check the float licence with  licence management?  check the licence just  when lauch the testcomplete ,or all the time ?

Thanks:)