thank you so much for your answer
yes, I was wrong to write long bytes though in compiling did not make me mistake.
I did not understand 2048 as it is 0x800 and send it at 0x08 and 0x00 at the same time
update:
i understand that it is in hex, but I do not know how to send them separately and recapture them in the slave.
is there a special function?