将csv文件上传到ftp服务器 - 文件为空

I am trying to store a file from my local server on an ftp server.

source file is in my current directory (same as php file)

I run the script with http://www.server.co.za/kisv2/xmltest/export.php

file to upload to ftp is http://www.server.co.za/kisv2/xmltest/exportfile.csv

destination ftp path is: ftp://ftp.ftpserver.co.za/LocExports/exportfile.csv

my ftp login defaults to: ftp://ftp.ftpserver.co.za

so I want to copy file from in current directory exportfile.csv to ftp://ftp.ftpserver.co.za/LocExports/exportfile.csv

My Current syntax is:

$source = 'exportfile.csv';  //this is a file in the same directory as my php file. full path is... http://www.server.co.za/kisv2/xmltest/exportfile.csv
$target = '/LocExports/exportfile.csv'; //full path is... ftp://ftp.ftpserver.co.za/LocExports/exportfile.csv

$conn = ftp_connect("ftp.ftpserver.co.za") or die("Could not connect");
ftp_login($conn, "username", "password");

$upload = ftp_put($conn, $target, $source, FTP_ASCII);
if (!$upload) { echo 'FTP upload failed!'; }

echo "complete";

This gives me error Warning: ftp_put() [function.ftp-put]: Opening ASCII mode data connection. the file does appear on the FTP server but is blank and 0bytes in size.

Any ideas welcome.

Thanks and regards

UPDATE

$source = 'exportfile.csv';  
$target = '/LocExports/exportfile.csv'; 

$conn = ftp_connect("ftp.server.co.za") or die("Could not connect");
ftp_login($conn, "username", "password");

ftp_pasv($conn, true); 

$upload = ftp_put($conn, $target, $source, FTP_BINARY);
if (!$upload) { echo 'FTP upload failed!'; }

echo "complete";

this still fails with: Warning: ftp_put() [function.ftp-put]: Opening BINARY mode data connection.

file is created on ftp but empty.

thanks again