Connect has a feature that will time a user out of the system if an extended period of inactivity is detected. The system essentially timestamps the last time an interaction occurs between a user and the Connect servers. If 60 minutes elapses since the last such interaction, the system pops up a warning and the user is prompted to click OK within the time allotted (an additional 60 minutes) to not get logged out.
It is worth noting that not all actions performed within Connect send a communication to the server. For example, working within a search (editing search criteria) will not communicate to the server, but communication with the server does occur when you run the actual search.
In most instances, it is confirmation-type actions, such as clicking a link/button or navigating between different parts of the system, that communicate with the server.
Essentially, you have two hours of inactivity before you will actually be logged out of the system- 60 minutes of inactivity until the warning message pops up, and then another 60 minutes from that point. If you do not perform an action that communicates with the servers within those 120 minutes, you will be logged out.