Text mode is supported by the SFTP protocol in versions 4 and later. To ensure that the connection is established using SFTP 4 or later, you need to enable SFTP 4, 5, and 6 and disable SFTP 1, 2, and 3 using the Versions property of the ElSimpleSftpClient or ElSftpClient components. See the documentation for information about how to set the Versions property in ElSimpleSFTPClient and ElSftpClient.

Also, not all servers support ASCII mode despite the fact that they support version 4 of the SFTP protocol. So, you may need to convert the file locally in your code before sending or after retrieving the file.