... as Control panel's ID, arm/disarm, pre-stored phone numbers, power supply) by sending SMS commands. 5 ... alarm is triggered. You can pick up the phone call to monitor the sound around the alarm.5 ... as Control panel's ID, arm/disarm, pre-stored phone numbers, power supply) by sending SMS commands.8. ... )is required to access to the GSM Alarm System to ensure more security.Technical ParametersGSM frequency:900 ...