php如何连接到串口Comm？
我尝试使用类php_serial.class.php，但这不起作用，当我运行网络时，发生错误
Warning: Specified serial port is not valid in D:\POS\AppServ\www\Eri\ulikan\phptoserial\gagal\php_serial.class.php on line 111
Warning: The device must be set before to be open in D:\POS\AppServ\www\Eri\ulikan\phptoserial\gagal\php_serial.class.php on line 137
Warning: Device must be opened in D:\POS\AppServ\www\Eri\ulikan\phptoserial\gagal\php_serial.class.php on line 541
Warning: Device must be opened to read it in D:\POS\AppServ\www\Eri\ulikan\phptoserial\gagal\php_serial.class.php on line 474
Warning: Unable to set the baud rate : the device is either not set or opened in D:\POS\AppServ\www\Eri\ulikan\phptoserial\gagal\php_serial.class.php on line 204