notfreeusername:
I will modify the code and send them seperately limiting the buffer to 150. If I manage to do it, I will post the code here.
I did not realize you are receiving the data on a Mega. It has enough SRAM to deal with the larger buffer size.
I connected to Tx3 and Rx3. It still doesn't receive the whole data.
Post the program in which you tried that.
...R