gistfile1.php

<?php
$connection = new SoapClient("https://<ip>/sdk/vimService.wsdl", 
    array(
        "trace" => 1, 
        "location"=>"https://<ip>/sdk/"
   )
);
// Preparation des parametres a passer a la methode
$soapMessage = array(
  "_this" => new SoapVar("ServiceInstance", XSD_STRING, "ServiceInstance")
);
// Appel de la methode "RetrieveServiceContent"
$result = $client->RetrieveServiceContent($soapMessage);
// Affichage du resultat
var_dump($result);