Hi,
You do not need the merge in your case option as you are running with only one processor.
FYI:
The execution of runcode.py can be cut in four part:
runcode.py --split -wdir temp_dir module cas
Which will only create the temporary folder and partion the files if necessary
runcode.py -x -wdir temp_dir module cas
That will compile your User Fortran File
runcode.py --run -wdir temp_dir module cas
That will run the code
runcode.py --merge -wdir temp_dir module cas
That will merge the partionned files if necessary and will copy back all the results files
The few important points are that you need the option -wdir to give a name to your temporary folder and you should add the option --ncsize as well.
Hope it helps,
Yoann