I have developed GCS. but I couldn't get Gps Data

Hi There, I have developed GCS.

But I have Some problem.

pixhawk is connected by Serial.

And then I received Data about Telemetry.

I could receive Hearbeat and StatusText.

But I couldn’t get GpsData such as Global Position, VFR_HUD.

Why I couldn’t get GpsData??I saw description about SERIAL_CONTROL… Should do I send to SERIAL_CONTROL??