After testing the inactivity timer, all I am seeing is the display on the set go to a screen saver when the timer expires. It does not prevent me from dialing from it however nor does it log me out. Do you suppose there is another setting that needs to be changed to enable the locking of the device?
Here is the description which appears to elude to the fact that enabling this timer would protect against unauthorized use?
Activity Timer
Locks the phone if idle longer than the timer value to protect against unauthorized use. Enter a value from 1 to 60 minutes or 0 (zero) to disable the timer and keep the phone from locking due to inactivity. If enabled, the timer also turns off or dims (as determined by the Backlighting Enabled COS option) the phone's backlight.
The timer applies to 53xx series phones only.
For hot desk users, the timer applies to the mobile directory number (DN), not the registration (phone) DN.
Activity on the phone includes, but is not limited to, the following:
User presses any key
User goes off hook
User touches the screen on a 5360
Any audio playback, including listen to music on hold. (Use of the Music feature to play audio while the set is idle is considered inactive time.)
NOTES
If the User Inactivity Timer is enabled, it overrides the Screen Saver timer.
Enabling the timer removes options for configuring the screen saver application on 5330, 5340, and 5360 IP Phones.