php 通过dio连接串口发送和读取数据

$com='COM1'; $baud = '57600'; $data='8';  $stop = '2';
exec('mode '.$com.': baud='.$baud.' data='.$data.' stop='.$stop.' parity=n xon=on',$output);

$handle = dio_open($com . ':', O_RDWR);

$data = "EF 01 FF FF FF FF 01 00 03 01 00 05";
$data = hex2bin(str_replace(" ", "", $data));
dio_write($handle, $data);

$response = dio_read ( $handle ,  12 );
$response =  bin2hex($response);

以hex发送和接收数据
dio_read为异步等待