How to use a Digi Gateway Wi-fi without a wi-fi router

I have a X2E-Z3C-W1-W Digi Gateway.
I want the possibility to connect a wi-fi smart phone directly (without a wi-fi router).
I know that is possible after pushing the button on the Digi gateway, but I want this possibility activated all the time.
How can I do ?

The Gateway goes into a temporary Ad-Hoc mode when you push the button, for purposes of configuration only. This Gateway is not designed to function as an Access Point.