I can't believe that no one should ever have seen or even used such a code already!
If you had then my belief would be right, so what do you mean?
So please show what you have and stop insulting me and arguing in a narrow-minded attitude!
the code should transfer a byte array (length >= 48) from one Arduino Mega to the other and then the other one sends a similar array back.
The array contains data e.g., for a remote control and/or for sensor reading and messaging (readings, manipulated variables, control values). The problem is not about coding or decoding the arrays or what to do with either values but just about failsave sending and receiving arrays and vice versa in quick cycles (at LEAST 10x per second, preferably even faster).