protected function tune(Reader $args)
    {
        $v = $args->readShort();
        if ($v) {
            $this->channelMax = $v;
        }

        $v = $args->readLong();

        if ($v) {
            $this->frameMax = $v;
        }

        $this->heartbeat = $args->readShort();

        $this->xTuneOk($this->channelMax, $this->frameMax, 0);
    }