The IoT Gateway Cellular RTU Can not send out SMS when alarm.
1. Please ensure the Cellular RTU is Armed, because of if the Cellular RTU supports Armed and Disarmed function, must in Armed then it can send out Alarm SMS to users;
2. Please check the user phone number, usually need to plus country code before phone number;
3. Please check the settings, if you phone number is the authorized number to receive the related alarm message;
4. Please check the SIMCard money and if it can register to the Cellular Network.