Thank you for reminding me for that. here are my code, very straight forward:

my $ftp = Net::FTP->new($input->{remote_ip}, Debug => 0, Timeout => 8)
+;

$ftp->login($input->{remote_login}, $input->{remote_password}) or push
+ (@$error_minilog, "Cannot login to repository: Invalid login or pass
+word");

$ftp->type('I');
$ftp->cwd($input->{remote_path}) or push (@$error_minilog, "Cannot cha
+nge repository path");

my $ftpret = $ftp->get("filename", "localfilename") or push (@$error_m
+inilog, "Failed to download file");
[download]

I try to print the $ftpret, it was null.