The GSM module is a remote control unit used to be advised of any potential alarm or problem in your tank, or can be called to have the latest tank measured value. The module has inside a GSM unit and require just the SIMM to be operative. The unit is equipped with Litium battery and can work also without powe energy, particulary it advise you when the main power wil be down and when is up. others alarm of system can be enabled by user to be sent or not, using the apposite panel control.
A simple SMS message with "query" as contenent sended to the unit will give you back the measured value.
As others modules of the system also the GSM unit can be updated with news firmware versione, with new improvement in functions.