10-2 Securitytime period after which the display will powerdown if the device remains inactive. This featuresaves the battery and increases the communica-tor’s operation time. The time-out value can bebetween 2 to 15 minutes. The screen power-down cannot be turned off.System sounds — System sounds are warning anderror tones, arriving message tone, key click tonesand alarm sounds. The available settings are:All sounds — Ring (default)/ Beep / Silent/Silent for. The All sounds setting affects in-coming call alerts and other alarms on bothinterfaces, with the exception of clock alarm.With Silent for, the communicator remains inSilent mode until the time you have enteredthere has passed (use 24-hour time format).Ringing volume — Level 1/2 (default)/3/4/5.Ringing tone — You can select one of thetones in the pop-up box or compose a specialringing tone for your telephone in the Extrasapplication.Key click — Off / Quiet (default)/ Loud.Warning tone — On (default) / Off.Application tones — Calendar alarm, Clockalarm, Received fax, Received SMS, Receivede-mail.For each of these individual settings you canset a specific ring type. You would then beable to tell by the ring whether you have re-ceived a fax or a short message, for example.The clock alarm will sound regardless of thecommunicator’s status. For example, when aphone call is active and the communicator isused in handsfree operation, all sounds exceptthe clock alarm are automatically turned off.Preferences — Preferences let you change dateand time formats and the measurement unit. Thepreferences list contains the following items:Date formatOctober 25, 1997, can be shown as:dd.mm.yy : 25.10.97mm-dd-yy: 10-25-97yy.mm.dd: 97.10.25Time format — 24 hour / AM/PM.Two o’clock in the afternoon can be shown as:14:002:00 PMUnit of measure — Choose either Centimeteror Inch as the basic unit of measureSecurityLocking the communicatorTo prevent outgoing calls from being made, youcan lock the communicator in the Security appli-cation’s main view.To use the Lock system key in System security,the Autolock period setting (defined in Systemsecurity, Settings) must be set to On.Highlight Autolock period and press Change.Enter the correct lock code (provided in the salespackage) to change the setting status.If autolock is on, the communicator will lockautomatically after the defined inactivity period.Press Lock system to lock the device manually atany time.You can also lock the system from the phone in-terface Menu 5 8 (see Chapter 13 "Phone inter-face: Detailed menus list - Security options(Menu 5)" on page 13-11).Unlocking the communicatorAfter the communicator has been locked, it can-not be used until the correct lock code is given.Incoming voice calls can, however, be answeredvia the phone interface.Note: When the communicator is locked, it maybe possible to make a call via the phoneinterface to the emergency number pro-grammed into your phone (e.g., 911 orother official emergency number).