Mike42\Escpos\Printer::wrapperSend2dCodeData PHP Метод

    private function wrapperSend2dCodeData($fn, $cn, $data = '', $m = '')
    {
        if (strlen($m) > 1 || strlen($cn) != 1 || strlen($fn) != 1) {
            throw new InvalidArgumentException("wrapperSend2dCodeData: cn and fn must be one character each.");
        }
        $header = $this->intLowHigh(strlen($data) + strlen($m) + 2, 2);
        $this->connector->write(self::GS . "(k" . $header . $cn . $fn . $m . $data);
    }