On Fri, 26 Jul 2002 14:25:44 -0300, Marcelo Puhl wrote:
>I wrote a Visual Basic program to sample an IO port every 10=
 mS.
>The program seems to miss samples when other programs are=
 running in
>Windows.
>
>Is there a way of reading an IO port in VB without missing=
 samples ?

The IO Control I used will sample the state of the serial ports=
 or the
parallel port each time the appropriate function is called. It=
 also
includes it's own Timer-like object that works down to 1mS.

Windows is far from a real-time operating system. You have little=

control over how long other programs hog the CPU when they are=
 running.

In my experience an I/O card or external device with its own=
 micro is
the best way to collect/control time critical things. Then you=
 can hand
the data or results off to Windows when it decides it's ready to=
 talk
with your device.

Tim

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