What can you use the Honeywell 7847i for?
You will be able to use the 7847i internet communicator to send signals to a central station monitoring service so that they may call the authorities if there's an alarm on your Vista system.
You will also be able to use the 7847i for Honeywell's Total Connect Interactive services. Total Connect will give you the ability to receive your own text or email messages of alarm events and also give you some limited remote control of the alarm system itself.