Problems with Parallel Port on Reboot

[Scot Hawkins]

Hi,

I use labview to drive my stepper motor connected to the parallel port
on my Win98 machine. The motor takes a step for every clock pulse sent
out on a particular pin on the port.

Although my problem is not directly related to labview, I was hoping to
get a solution. Every time I reboot my computer (at least once a day,
it seems) the computer sends a series of clock pulses to the port,
moving my motor several hundred steps. I cannot tell if it's a regular
series of pulses or just random noise.

Is there a way to disable the lpt port or otherwise prevent spurious
noise being sent out to my motor when rebooting my machine? Or when
labview is not running?

Thanks,

Scot

[Jim_Kring]

Windows likes to check for plug-n-play devices when it boots up. You may want to set up a relay/interlock gating system that only allows pulses to reach the motor driver when one digital line is high and another other digital line is low.

-Jim

[Lab Viewer]

Hi Scot,
a workaround could be a DB25 parallel port Switch Box (in the same time, you can access easier a printer using the same port). The price is around 20$.
Hope this helps ... somehow