The GCX ConneXion bar requires the system to be setup for doing PGT requests.  The way this works, is you need to have a callback url on the local server, for the GCX server to send a PGTIOU via GET.

Callback Page ::
<?php
  include_once('CAS/CAS.php');
  phpCAS::proxy(CAS_VERSION_2_0, 'signing.mygcx.org', 443, 'cas');
  phpCAS::setFixedCallbackURL( ** Callback url, aka the link to this page **);
  phpCAS::setNoCasServerValidation(); //remove requirement for SSL validation
  phpCAS::setPGTStorageFile('xml', "some accessible directory to store PGTIOUs in");
  phpCAS::forceAuthentication();
?>



Other Pages ::
Same as above, plus the following:
<?php
  $cnxbar = 'http://www.mygcx.org/COMMUNITY/module/omnibar/omnibar'; // Replace COMMUNITY with the community name, if unsure public or global will work too.
  if(phpCAS::serviceWeb($cnxbar, $err_code, $output)) {
    $xml = simplexml_load_string($output);
    $result = $xml->xpath('/reportoutput/reportdata');
    $connexionbarcode = html_entity_decode($result[0]->asXML());
  }
  echo $connexionbarcode;
?>


Of note:
You must use the proxy, and not the client.
The callback URL needs to be accessible from the interweb
The PGTStorageFile can also be done with a database, check the docs for more infor
The PGTStorageFile must be readable and writable
The GCX server is using a modified form of CAS.  For this to work, you must use the libraries that they have tweaked.  It relaxes some of the SSL requirements even further, among other things.
The callback URL isn't necessarilly required, I think it will default to the page which made the request.