Select, by file extension, file types that should always be transferred in ASCII mode.
From the menu, choose Tools > Global Options.
Expand Transfer.
Select ASCII Types.
Type the file extension for files you want to transfer in ASCII mode in this box.
SelectAdd to add the extension to the list.
Select Remove to delete the selected extension from the list.
Note:
You can specify a Transfer type from the main menu (see Transferring files in binary or ASCII mode). You can also specify a Transfer type for an individual site by highlighting the site in the Site Manager, clicking the Type tab, and choosing from the Transfer list. Auto is the default transfer type, and sends files in the mode specified for each file's extension. All extensions are sent in binary mode unless they are listed in theASCII Extensions list.