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How to monitor parallel port data of win 3.1 system

Hi O_Proulx,

From my monitor log, it looks like the first 700 lines of communication exactly matches the contents of a file in the host PC which the software is reading and sending to the peripheral. At the end of transmission it send "G1000". The last character '0' is shown in the log snippet I posted before. At 11:08:41, host PC send the last '0', after which there seems to be no more activity neither from host nor from the peripheral. My monitor ran till the host software came up with the error "file downloaded but device wouldn't start" and quits.


Aromal Lilly
Columbus, OH
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Message 21 of 23

Hi O_Proulx,

In another thread few weeks back, Nick F. had suggested me to try using hardware timed capture DAQ device. We had earlier bought the NI USB 6501 which use software timed capture, so could not log all information because windows limits the speed of capture to every 1 or 1.5 ms whereas the parallel port events are usually in microseconds range.

I want to know if the NI PCI-6250 can be used to monitor parallel port events with sufficient speed. The parallel port event like strobe will last for minimum 0.75 us. We need to monitor 8 data, 4 control and 5 status lines (17 lines in total). The  PCI-6250 spec says it has 24 DIO channels, hardware timing, max clock rate of 10 MHz. So if we use this device with the NI labview express software, can it record all parallel port events(>=0.75 us) for a duration of 5 minutes or more and generate a log file?


Aromal Lilly
Columbus, OH
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Message 22 of 23
Hello Aro,

The 6250 will not work because there are only 8 hardware (correlated) DIO line on it.  I suggest an NI-6534, which is a Digital IO board (in comparison to a multifunction DAQ).  It has 32 hardware timed DIO lines clocked at 20Mhz.  I think this is will help you do what you want.

Let me know if you have any questions.  Have a great day.

O. Proulx
National Instruments
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Message 23 of 23