[What byte i supposed to send to the machine to get data Via Bluetooth]

Hye Everybody,

I'm in trouble trying to communicate with my UNIDDE through Android application.

I make a connection between my smartphone and the UNIDDE successfully. 

Now, i want to receive the data after the machine make some operation and calculation.

My question is: What byte i supposed to send to the machine to get data or how i can get data.

So, anybody could have an idea 

Thanks