Looking at the Net::FTP code (try it, you'll like it!) it looks like the get() method returns the name of the local file name if successful, undef if not. Try something like this:

my $localname = $ftp->get("$path$station.TXT", "$datapath$station.TXT"
+);
die "Something went wrong" unless defined $localname;
$ftp->quit;
[download]

You may want more robust error handling, but I just tested that and it works.