Node JS JSftp Get binary data, return string

I am relatively new on Node JS. I am working on an application fetching XML-files from a server. In summary I want to do this:

1. Download XML-files from FTP server and store the XML-content as a string.
2. Return the string to the browser as plain text.

I am able to use jsftp.get to download files to a local directory, but I am not able to get the downloaded data as a string.

What am I doing wrong?

My code is like this:

var http = require("http");
var url = require("url");
var JSFtp = require("jsftp");
var myStrToReturn = new String();


http.createServer(function(req, res) {

  // URL
  var parsedUrl = url.parse(req.url, true);
  var queryAsObject = parsedUrl.query;

  var str = new String();
  var myFunction = queryAsObject["function"];

  var Ftp = new JSFtp({
  host: "ftp.ftp.ftp",
  port: 21, // defaults to 21
  user: "user", // defaults to "anonymous"
  pass: "passwd", // defaults to "@anonymous"
  debugMode: true

});

var str = "";
Ftp.get("Production/Offers/datafile.xml", function(err, socket) {

    if (err) return;
    socket.on("data", function(d) { str += d.toString(); })
    socket.on("close", function(hadErr) {
      if (hadErr)
        console.error('There was an error retrieving the file.');
    });
    socket.resume();
  });
    myStrToReturn = str.toString("binary");

    res.writeHead(200, {
        'Content-Encoding':'utf-8',
        'charset' : 'utf-8',
        'Content-Type': 'text/plain;charset=utf-8'});
    res.write(myStrToReturn.toString());
    res.end();

console.log(myStrToReturn);
  });

Ftp.on('jsftp_debug', function(eventType, data) {
  console.log('DEBUG: ', eventType);
  console.log(JSON.stringify(data, null, 2));
});

}).listen(8030);

console.log("Server listening on port 8030");