ftp: FTP Functions

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FTP functions are used to send and receive files by using FTP (File Transfer Protocol).

FTP is an internet standard (RFC 959) for file transmission across IP networks.

The RTCU devices exclusively uses Passive (PASV) mode for file transfer.

Note:

On many FTP servers, the name of files and folders are case sensitive.

The handling of error situations like lost connection may vary from server to server.

Secure connection

For NX32L devices, support for FTPS (FTP secure) is available using TLS (TLS v1.2, v1.1 or 1.0).

To use secure connection:

1. Ensure the root certificate needed to verify the FTP server is present.

2. When calling ftpConnect set the 'security' to the required type of security. E.g. 'security := 1' (use FTPS if the server supports this).

Functions used for server communication:

Functions operating on directories:

	•ftpDirChange	Changes working directory.
	•ftpDirCreate	Creates a directory.
	•ftpDirCurrent	Gets working directory.
	•ftpDirDelete	Deletes a directory.
	•ftpDirRename	Renames a directory.
	•ftpDirCatalogGet	Fetches catalog.
	•ftpDirCatalog	Gets an entry from a fetched catalog.

Functions operating on files:

Receiving / sending a file over FTP

The following sequence is required to send or receive a file:

1.	ftpOpen	Initialize the FTP functions.
2.	ftpConnect	Connect to server.
3.	ftpFileSend / ftpFileReceive	Send/receive a file.
4.	ftpDisconnect	Disconnect from server.
5.	ftpClose	Finish working with FTP.

The implementation of FTP has the following limitations:

•Only passive FTP is allowed.

•An IP-network connection must be available.

•File system must be present and open for sending and receiving files.

•When fetching catalogs, only the first 64 files in 8.3 format are listed.