Revisa si esto te puede servir, es para escribir datos:
http://www.php.net/manual/en/function.fopen.php#20935 Código PHP:
<?php
// HOW TO USE PHP TO WRITE TO YOUR SERIAL PORT: TWO METHODS
$serproxy=true;
if ($serproxy) {
// Use this code in conjunction with SERPROXY.EXE
// (http://www.lspace.nildram.co.uk/freeware.html)
// which converts a Serial stream to a TCP/IP stream
$fp = fsockopen ("localhost", 5331, $errno, $errstr, 30);
if (!$fp) {
echo "$errstr ($errno)";
} else {
$e = chr(27);
$string = $e . "A" . $e . "H300";
$string .= $e . "V100" . $e . "XL1SATO";
$string .= $e . "Q1" . $e . "Z";
echo $string;
fputs ($fp, $string );
fclose ($fp);
}
} elseif ($com1) {
// Use this code to write directly to the COM1 serial port
// First, you want to set the mode of the port. You need to set
// it only once; it will remain the same until you reboot.
// Note: the backticks on the following line will execute the
// DOS 'mode' command from within PHP
`mode com1: BAUD=9600 PARITY=N data=8 stop=1 xon=off`;
$fp = fopen ("COM1:", "w+");
if (!$fp) {
echo "Uh-oh. Port not opened.";
} else {
$e = chr(27);
$string = $e . "A" . $e . "H300";
$string .= $e . "V100" . $e . "XL1SATO";
$string .= $e . "Q1" . $e . "Z";
echo $string;
fputs ($fp, $string );
fclose ($fp);
}
}
?>