In junipercmd you have:

Prompt => '/ERX02>$/'

But in your example the prompt returned is

ERX02#
[download]

So it won't match, thus won't return command to your program. Try a simple ERXO2. You really only need to set this once. ***You probably don't even need to set it at all as there is an inbuilt default that should work***.

As an aside you are obviously not using strict and passing things around as globals - this is bad. The logic for having subs that simply serve as more or less useless wrappers around the existing functions in Net::Telnet::Cisco eludes me. In your prompt RE you have @[ which will not be doing what you think it does, whatever that might be.

Does this work:

#!/usr/bin/perl
use Net::Telnet::Cisco;
use strict;

my $rtrip = 'xx.xx.xx.xxx';
my $user  = 'login';
my $pass  = 'support123';
my $cmd   = 'some command';

my $session = Net::Telnet::Cisco->new( Host    => $rtrip, 
                                       Prompt  => '/ERX02/,
                                       Timeout => '30');
$session->login( Name     => $login, 
                 Password => $pass, );

my @output = $session->cmd($cmd);
print @output;
[download]