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PCI-6503 - One Port = In / One Port = Out

On the PCI-6503 card with the 8255, I wan't one port use as input and
one port as output. To read from the port, I use the "Port Read" VI
(from the advanced section - not the "Dig Line" or the "Dig Port"
(from the Easy DIO) nor the "DIO Read"). But when ever this VI is
called, all the ports from the 8255 are resetet.

Wich VI do I have to use, that this does not happen ? Or is there no
other way, then first read the port an then write the other port from
a softcopy again (whould surprise me, if I had to do it this way).
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Hi cs,

The one particularity with the 8255 is that it resests the entire chip
whenever any of the ports on the chip is configured. However, you
should have access to read and write to the ports once they are
configured and not have this problem. Here are some resources
discussing this particular problem:

Why Do All My Digital I/O Ports Reset When I Configure One Port?
http://digital.ni.com/public.nsf/websearch/3E25A9780F2C48B986256120005AF098?OpenDocument

What I suggest is that you use the DIO Port Config.vi to configure
your ports initially. Once both ports are configured for their
respective directions you can use DIO Port Write or DIO Port Read and
it shouldn't reset the chip.

Anyway, hope that helps. Have a good day.

Ron
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thanks. I met the same problem these days, finally i had the answer here.
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