Change Advanced preferences
Use the Advanced pane of Security & Privacy preferences to adjust the security settings of your Mac.
To open this pane on your Mac, choose Apple menu 
> System Preferences, click Security & Privacy, then click Advanced.
Open Security & Privacy preferences for me
Log out after... minutes of inactivity | Select to automatically log out users after the Mac is idle for the given number of minutes. |
Require an administrator password to access system-wide preferences | Select to prevent users from changing locked system preferences without an administrator’s password. |
Disable remote control infrared receiver | Select to prevent your Mac from receiving commands from an infrared remote control. (This option appears on Mac computers with infrared receivers.) To configure your Mac to respond to an infrared remote control, deselect the checkbox, click Pair, then follow the onscreen instructions. |
Turn on screen saver when login token is removed | Select to turn on the screen saver on your Mac when a Smart Card containing a login token is removed. (This option appears when you insert a Smart Card that has been added to your login keychain.) |