sorry, disktrading well and can not give/write direct the native binary ninja data format...
"disktrading" give only different "ASCII" formats for any applications.
(only the old TradeStation GlobalServer binary format is direct supported)
The read support of "ntd" files is now public(example: gomi's ninja mode), the full write support is tricky and not version stable... on this time i dont know any public non ninja tool with true self write/append "ntd" files.