Mikrotik routerboard backup using SFTP

Hello guys, i have problem with this code. I'm tryin to get backup file from Mikrotik routerboards using following code. But when run this code "10: Resource temporarily unavailable" error appeared. Someone help me pls
package main;

import java.util.Properties;
import com.jcraft.jsch.*;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.Channel;


public class Main {

public static void main(String args[])
{
String host = "ip address";
String username = "admin";
String password = "pass";
String command = "system backup save name=backup_name";
String rfile = "backup_name.backup";
String ftpRemoteDirectory = "/files/";
int port = 22;

try{
JSch jsch = new JSch();
Session session = jsch.getSession(username, host, port);
session.setPassword(password);
java.util.Properties config = new java.util.Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
System.out.println("connecting...");
session.connect();
System.out.println("connected.");

Channel channel = session.openChannel("exec");
((ChannelExec)channel).setCommand(command);
channel.connect();

Channel cp_channel = session.openChannel("sftp");
cp_channel.connect();
ChannelSftp sftpChannel = (ChannelSftp)cp_channel;
sftpChannel.get("../file/2012/11/backup_name.backup", "D:/backup_name.backup");
sftpChannel.exit();
cp_channel.connect();
channel.disconnect();
cp_channel.disconnect();
session.disconnect();

}
catch(Exception e)
{
System.err.print(e);
}


}


}

 

Hmmm, first command is usable... Second command, I don't know how to convert it for plink.
I'm using a plink.exe for that but I have no idea how to make it download configuration or at least, I don't know what command is used to download backup file. Creation of backup file would be like.