You'll want to go to the "Aux" page group, then go to the "System" tab.
From there you will see a "Status" button on the lower left side of the display. It defaults to "Status - Software".
You'll want to cycle that key until it shows "Status - GPS".
This is also where you can find your datalink status (by cycling the status button one more time). I've attached a video shot from our bench setup. Ignore the errors on my unit, as we didn't have GPS among other things connected at the time.
