There is no time out setting for access to FIMS Host*Net.  If you are getting a time out message, it is actually a time out for Citrix.  The time out for Citrix is 30 minutes and cannot be changed for security reasons. 

If you have closed FIMS but are still getting a time out message popping up, right click on the little Citrix icon on your lower task bar, then click Disconnect.