In the file Mask in the ftp directory you are using "MA1_*".txt". This will pull all the files from your local directory.
1. Either you can create 1 folder under S01_MA1 folder on the local machine and keep the latest file there and copy from there to ftp server. Delete this file at the end of the run
2. Dynamically create the file name dynamically (if it is feasible) and use that in the file mask