The following settings in BMC Atrium Single Sign-On control the timeout behavior in the TrueSight console:
Max Session Time - Time after which your session is logged out, even when you are active. The default is 120 minutes; maximum is 20160 minutes.
Idle Timeout - Time after which your session is logged out if you are inactive or away. The default is 30 minutes; maximum is 10080 minutes.
Access these settings from the Server Configuration Editor page of the BMC Atrium SSO Admin Console. For more information, see the documentation.