Hello List, I have managed to communicate with the serial device with the following code: 'mode com1: BAUD=9600 PARITY=N data=8 stop=1 xon=n'; //the config the device needs $fp = fopen("COM1:", "rb+"); //also tried only "r+" here if(!$fp) die(); $query = chr(59).chr(32)."0".chr(13).chr(10); fputs($fp, $query); $reply = fgets($fp, 32); print($reply); This works, the "0"-command requests the ID of the device and the reply I get in $reply is exactly what it should be. The problem: it takes around 5 seconds until this reply is there, I tried different lengths to buffer in fgets, tried fgetc, fread, everything, always the same. It can't be the device blocking it, because if I send a couple of commands (to position the devices measurement head) it reacts to all of these commands in lightning speed, so I don't think it is the device slowing the thing down, BUT what could it be? Does anybody have any experience with this??? Basically, fread/fgets/fgetc just hangs the PHP core for several seconds, with 0-1% CPU load...something just stalls PHP for this peroid of time. If this is an internal problem of PHP: does anybody know a source where I can find some hints on how to communicate with the serial port over the COM implementation of php-win? Googling for "com serial port php" is a bit troublesom, since "com" in this case finds dozens of sites where com refers to "com1" and not the COM system of Win32. Any help is greatly appreciated! best regards Ulrik -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php