Parsing NWS XML Data - cap:geocode

I followed the info here:

Parse XML namespaces with php SimpleXML

And that works for everything except the information contained in the "cap:geocode" and "cap:parameter" entries.

$geocode = $entry->children('cap',true)->geocode;

returns an empty value.

Any ideas on how to get at the data inside of the cap:geocode and cap:parameter entries?

<cap:geocode>
    <valueName>FIPS6</valueName>
    <value>048017 048079</value>
    <valueName>UGC</valueName>
    <value>TXZ027 TXZ033</value>
</cap:geocode>

I need to read the ValueName/Value pairs.

I used this example here: https://github.com/tylerlane/php.news-leader.com/blob/master/weather/alerts.php

And simplified it for my purposes to get this (echo.php just prints the data out):

$dataFileName = "wx/CAP.xml";
//load the feed
$capXML = simplexml_load_file($dataFileName);
//how many items
$itemsTotal = count($capXML->entry);
if(count($itemsTotal)):
$capXML->registerXPathNamespace('prefix', 'http://www.w3.org/2005/Atom');
$result = $capXML->xpath("//prefix:entry");

foreach($result as $capXML):
        $dc = $capXML->children('urn:oasis:names:tc:emergency:cap:1.1');
        $event = $dc->event;
        $effective = $dc->effective;
        $expires = $dc->expires;
        $status = $dc->status;
        $msgType = $dc->msgType;
        $category = $dc->category;
        $urgency = $dc->urgency;
        $severity = $dc->severity;
        $certainty = $dc->certainty;
        $areadesc = $dc->areaDesc;
        $geopolygon = $dc->polygon;
        //get the children of the geocode element
        $geocodechildren = $dc->geocode->children();
        //only interested in FIPS6 for now
        //no guarantee that FIPS6 will be the first child so we have to deal with that
        if($geocodechildren->valueName == "FIPS6"){
            //isolate all the FIPS codes
            $fips = explode( " ", $geocodechildren->value );

        } else {
            //hide everything else so we don't fail
            $fips = Array();
        }
        //get the VTEC
        $parameter_children = $dc->parameter->children();
        if($parameter_children->valueName == "VTEC"){
            //isolate all VTEC codes
            $vtec = explode( ".", $parameter_children->value );

        } else {
            //hide anything else that may show up
            $vtec = Array();
        }

        include('echo.php');
        print_r($fips);
        echo "<br/>";
        print_r($vtec);
        echo "<hr/>";
endforeach;
endif;