FTP: connection and file management

This page explains how to connect to the FTP server of a Yaskawa Motoman controller with the SDK, which account to use, and how to list, test and delete files. It covers the YRC1000 and YRC1000micro controllers. File transfers are on the next page, FTP file transfers.

What the FTP client does

The controller has an FTP server on TCP port 21. The SDK connects to it, logs in, and gives you methods to list, download, upload and delete the files of the controller. Every FTP method has an async version in .NET (GetListingAsync, DownloadFileAsync...).

FTP is the fastest way to transfer large files: ALL.PRM (1.4 MB) is downloaded in about 13 s on a YRC1000micro, against about 45 s with the High Speed Ethernet Server.

Prerequisites

• The PC reaches the controller on TCP port 21. A firewall between them must let the FTP connections through.
• The FTP server function is enabled on the controller. Depending on the controller and its settings, it can also need the command remote: see Prepare the controller. On the YRC1000micro used to test this page, FTP works in teach mode, without the command remote.

Accounts

The account gives the rights. "Download" means from the controller to the PC, "upload" from the PC to the controller.

The rights depend on the controller and on its software version: on the YRC1000micro used to test this page, anonymous also downloads the parameter files. ftp and anonymous work in the standard security mode only. When the password protection option is enabled on the controller, only the user and the password defined in this option are accepted.

Connect

Enable FTP

Set Ftp.Enable to true in ConnectParameters, and choose the account. Unlike the other protocols, Connect opens the FTP session and logs in at once: a wrong address or a wrong password fails in Connect.

static void Main()
{
var parameters = new ConnectParameters("192.168.0.1");
parameters.Ftp.Enable = true;

// "anonymous" (default): download only. "ftp": download and upload.
// "rcmaster" with the password of the management mode: every right.
parameters.Ftp.FtpUser = "ftp";
parameters.Ftp.FtpPassword = null;

parameters.Ftp.Port = 21;                    // default
parameters.Ftp.TimeoutMilliseconds = 30000;  // default

var robot = new YaskawaRobot();
robot.Connect(parameters); // opens the FTP session and logs in

Console.WriteLine($"Logged as {robot.Ftp.User}");
robot.Disconnect();
}

Standalone client

FtpClient opens an FTP client without YaskawaRobot. Connect takes the address, the user, the password, the port and the timeout.

static void Main()
{
// An FTP client without YaskawaRobot
var client = new FtpClient();
client.Connect("192.168.0.1", "ftp");

foreach (FtpListItem item in client.GetListing("/"))
    Console.WriteLine(item.FullName); // /JOB, /DAT, /CND, /SYS, /PRM...

client.Close();
}
}

List and test the files

var robot = new YaskawaRobot();
robot.Connect(parameters);
// Folders of the controller: /JOB, /DAT, /CND, /SYS, /PRM, /LST, /CSV, /LOG, /TXT
foreach (FtpListItem item in robot.Ftp.GetListing("/JOB"))
    Console.WriteLine($"{item.Name} {item.Modified:yyyy-MM-dd HH:mm} {item.Type}");

// File names by type, or by pattern
string[] jobs = robot.Ftp.GetFileList(FileExtension.JOB);
string[] parameterFiles = robot.Ftp.GetFileListByPattern("*.PRM");

// Test a file or a folder
bool exists = robot.Ftp.FileExists("/JOB/TEST.JBI");
bool folder = robot.Ftp.DirectoryExists("/JOB");
robot.Disconnect();
}

The root of the controller has one folder per type of file: /JOB, /DAT, /CND, /SYS, /PRM, /LST, /CSV, /LOG, /TXT.

The controller does not give the size of the files in the listing. Download a file to know its size.

Delete a file

DeleteFile(name) deletes a file. The folder is found from the extension. It needs the ftp or rcmaster account. There is no undo: download the file first if you may need it.

The controller does not overwrite a job by FTP. To replace a job, delete it, then send the new one:

var robot = new YaskawaRobot();
robot.Connect(parameters);
// A job must be deleted before it is sent again: the controller does not overwrite a job by FTP
if (robot.Ftp.FileExists("/JOB/NEWJOB.JBI"))
    robot.Ftp.DeleteFile("NEWJOB.JBI");

robot.Ftp.LoadFile("NEWJOB.JBI", File.ReadAllText("NEWJOB.JBI"));
robot.Disconnect();
}

Errors

Each failure throws an FtpException, with the operation, the file and the reason.

var robot = new YaskawaRobot();
robot.Connect(parameters);
try
{
    robot.Ftp.LoadFile("NEWJOB.JBI", File.ReadAllText("NEWJOB.JBI"));
}
catch (FtpException ex)
{
    // Reason: LoginIncorrect, AccessDenied, FileNotFound, JobAlreadyExists, DeleteRefused, ConnectionError
    Console.WriteLine($"{ex.Operation} of {ex.RemotePath} failed: {ex.Reason}");
    Console.WriteLine($"Controller reply {ex.ReplyCode}: {ex.ReplyMessage}");
}
robot.Disconnect();
}

Reference

// Deletes a file from the robot controller. The "anonymous" user cannot delete files.
void DeleteFile(string fileName);

// Checks whether a folder exists on the controller.
bool DirectoryExists(string path);

// Checks whether a file exists on the controller.
bool FileExists(string remotePath);

// Lists the files of the specified type on the controller.
string[] GetFileList(FileExtension fileExtension);

// Lists the files whose names match the specified pattern. When the pattern has a known extension (e.g. "*.JBI"), only the matching folder is listed. Otherwise, all folders of the controller are listed.
string[] GetFileListByPattern(string pattern);

// Returns the files and folders at the specified path on the controller. The root contains one folder per file type (JOB, DAT, CND, SYS, PRM, LST, CSV, LOG, TXT).
FtpListItem[] GetListing(string path);

Every method also exists in an asynchronous version, with the same name followed by Async and an optional CancellationToken.

What to read next

• FTP file transfers: download and upload text, bytes and local files.
• Transfer files and backups: FTP, HTTP or High Speed Ethernet Server.