def getControlURL(self, serviceType, default=None):
        """Returns the control URL for a given service type.

        When the device definitions have been loaded with :meth:`~simpletr64.DeviceTR64.loadDeviceDefinitions` this
        method returns for a given service type/namespace the associated control URL. If the device definitions have
        not been loaded a default value can be given which gets returned instead. The control URL is used to
        execute actions for a dedicated service type/namespace.

        :param serviceType: the service type to look up for
        :param default: the default return value in case the service type is not found and device definitions are not
            loaded
        :type default: str or None
        :return: the URL/URI
        :rtype: str or None
        :raises ValueError: if the device did load device definitions and the service type is not known.

        .. seealso::

            :meth:`~simpletr64.DeviceTR64.loadDeviceDefinitions`
        """
        if serviceType in self.__deviceServiceDefinitions.keys():
            return self.__deviceServiceDefinitions[serviceType]["controlURL"]

        # check if definitions have been loaded, then dont return the default
        if self.__deviceXMLInitialized:
            raise ValueError("Device do not support given serviceType: " + serviceType)

        return default