Calculate time before meeting response_timeout in Nusoap php

I am new to this from WebServices with php, and I have a problem, I hope this great community can help me.

I am consuming a method of a web service, but if it does not respond within 40 seconds I am asked to execute a query method to know the status of the request.

Searching I found that I can assign the response_timeout and assign it 40 seconds but when it was fulfilled, as it did not receive a response, it sent me an error and for a strange reason when I execute the query method, it marks me an error. How can I know or calculate 10 seconds, before the assigned time is reached in response_timeout?

This is my code ..

//Código para conexión

$client = new nusoap_client('https://testservice/Servicio?wsdl', 'wsdl' , 
false, false, false, false, 0, 40);

//Ingresamos usuario y contraseña paara el servicio web

$client->setCredentials($username,$password);

$err = $client->getError();

if ($err) {

 echo '<h2>Error</h2><pre>' . $err . '</pre>'; 

}

$proxy = $client->getProxy();
    //Define parametros a enviar 
    $parametros = array('id_cadena'=>$id_cadena, 
                        'id_tienda'=>$id_tienda,
                        'id_terminal'=>$id_terminal,
                        'folio'=>$folio,
                        'fechaLocal'=>$fechaLocal,
                        'referencia'=>$referencia,
                        'monto'=>$monto,
                        'sku'=>$sku);
    $start = time();
    $result = $proxy->venta($parametros);
    //$result = $client->call("venta",$parametros);
    $timing = time() - $start;
if($timing > 30 && $timing < 46){
        echo utf8_decode('<script>alert("Metodo consulta venta Tiempo inicial '.$start.' tiempo final'.$timing.'")</script>');
        $resultcon = $proxy->consultaVenta($parametros);
        $respuestacon = array($resultcon); 
        $_SESSION['respuestaVen']=$respuestacon;

        $codigo = $respuestacon[0]['return']['respuesta']['codigoRespuesta'];

        echo utf8_decode('<script>alert("Valor de codigo '.$codigo.'")</script>');  
    }