>Hi,
>I've an app the reads 4 comm ports sequentially for RS232 input data in quick succession. All 4 comms are read within a span of one second. In switching from one com to another, I use the portopen method to open & close each accordingly.
>The problem is that after a random amount of time, the portopen method generates an error "Unable to open port due to invalid parameter". I've checked thru all the parameters but found no invalid parameter.
>It only happens when I'm reading from comm ports that are not onboard but that are from a serial Comm PCI card inserted to expand the number of comm ports to 4 instead of the standard 2.
>I've read that MScomm32 has a problem with memory leaks upon repeated usage but I'm already on VFP6SP3. (it was documented to be fixed in Visual Studio 97 SP3).
>I've tried the app on WinXP as well as Win98SE with the same result.
>Worse was when I tried to use USB to Serial converters where the XP machine generated a core dump and had to be shut down.
>Any clues to what's the cause?
>Any help is appreciated.
>Yau

Hi - perhaps its time to change your tools ? Switch over to CommTools and see if this makes any difference in your application.
mondo regards [Bill]