it works as explained before, but for testing your program please upload your S7Program or test project here.

You are using "DW#16#870000B8" to write to a target STRING.It is totally wrong.Based on information related to pointers, you want to write your data in area allocated for "Block parameter transfer".For doing your task, read carefully the entire thread, and also find out more about concept of indirect addressing.

L P##out_string
LAR1

//if explain this line, it dosen't work! L #out_string[1]
L 's'
T B [AR1,P#2.0]


If it is difficult to handle, try to use ANY pointer or pointer(DB Pointer) itself as input to know where to manipulate.