Use the DSNTYPE statement to specify whether FTP creates local physical sequential data sets as physical sequential basic format data sets or physical sequential large format data sets. You can also use the SIte and LOCSIte subcommands to set this keyword.
.-DSNTYPE SYSTEM------. >>-+---------------------+------------------------------------->< '-DSNTYPE--+-BASIC--+-' +-LARGE--+ '-SYSTEM-'
To allocate new physical sequential data sets as physical large format data sets, code the following statement in FTP.DATA:
DSNTYPE LARGE