Your explanation of what you are trying to do is not at all clear.
I have it working as the program I'm using needs a reply of HEX "10 0a", and this is what I am sending.
The 0x0a is a line feed, do all the commands therefor need a line feed at the end?
How many bytes is the receiving side expecting and in what format?
Please read the how to use the forum sticky before posting ant more code.