The G1-4G GSM controller is designed to remotely control a relay output on an authorised incoming call. The unit will check the database of allowed users, reject the call and only switch the relay if the user is on the authorised list.
The alarm input can also be used to detect any kind of switched event such as an alarm activation, door contacts, gate held open etc. The SMS can be customised. The unit will send a customisable SMS notifcation to up to 5 user phones on the detected activity.
With superior reliability, configurability, easy remote management and 7-day phone support, the G1-4G is not the cheapest available but it is most certainly one of the most fully featured and reliable GSM remote control systems available.