Solution:

There is one way to add CR and LF in USER PROGRAM block, you can use "sprintf()" in USER PROGRAM to add "CR" and "LF" with string. The "CR" is typed as "\r" and "LF" is typed as "\n" in sprintf(). For example, if you type "sprintf(a1,"test %s \n","test);" in USER PROGRAM block. Then a1 will be "test test" comes with an "LF". When you connect USER PROGRAM block with RS-232 block, the output of USER PROGRAM block will be feed into prompt string of RS-232 block automatically.