Serial communication, which byte(s) is which parameter

Hey folks,
I have again question about serial communication. I have managed to set up a communication between my PX4 flight controller and a MATLAB based “ground station” PC via 3DR radio.

In the QGroundControl software under “Analyze” I can see a list of parameters which are received / transmitted. Now, I would like to know, which byte(s) exactly define, for example, the “M1:ATTITUDE.roll” parameter.

Is there maybe a list like, byte 1 to 4 is “M1:ATTITUDE.rollspeed”, byte 12-16 is “M1:AHRS.altitude” and so on…?
Or in general, how does QGroundControl know byte 24-28 is “M1:ATTITUDE.pitchspeed”, or whatever… :wink:
Thanks a lot :slight_smile:

QGC code that does that is here:

Thank you, @DonLakeFlyer!