For security, a visitor will be logged out after 60 minutes of inactivity if they are logged into a Document using one of the below Security Rules:

After 58 minutes of inactivity the visitor will be shown a popup message with a countdown indicating that their session will time out in 2 mins. If they click the 'Continue' button their session will stay active for another 60 mins. If they do not, once the countdown reaches 0 they will be logged out and shown a message with a button to login again.