Fortigate automatic call home to Fortimanager

I am new to the FortiFamily of products and I have a question about the firewalls calling back to the fortimanager. I know how we can add a device and add a model device. I also know how to manually make the fortigate call home and request the fortimanager. What I want to know about it I would like to know if there is a way to set the firewall to automatically call back to fortimanager on it's own? We ship firewalls all over the country and right now I am just connecting with the client and then connecting to it through add device wizard. Is there a way to have it send that request on it's own as soon as it is connected?