Slow serial communication

[George]

We are trying an old Win 3.1/95/98 software that
communicates through the serial port with a specialized
system(National Instruments Labview). Works fine for 3.1,
95 and 98 but acts sluggish with data communication delay
indications. I have tried the roll-back feature in XP
professional with no difference. Otherwise software works
fine, just the periodic delay of up to 20 seconds for
normal once per second communication at 19,200.

 

[Peter Hutchison]

We are trying an old Win 3.1/95/98 software that
communicates through the serial port with a specialized
system(National Instruments Labview). Works fine for 3.1,
95 and 98 but acts sluggish with data communication delay
indications. I have tried the roll-back feature in XP
professional with no difference. Otherwise software works
fine, just the periodic delay of up to 20 seconds for
normal once per second communication at 19,200.

The problem is that direct access to the serial port is more
restricted in NT/2K/XP systems. The software needs to be updated to
use the OS API to access the Serial Port rather than directly.
For now, I would NOT use NT based systems for this software.

Peter Hutchison
Windows FAQ
http://www.pcguru.plus.com/