Re: How can I display a TTL- Signal which is impressed at a serial- or a parallel port

[Dennis Knutson]

You serial port didn't work because the RS-232 signals are not TTL.
They are >+3V and <-3V. Your parallel port should be able to do the
trick though. You can use the Inport function (Advanced>Port I/O
palette) to read. There is a brief tutorial <A
href="http://zone.ni.com/devzone/conceptd.nsf/webmain/72C6FC6CE4AD4D1386256B1800794596?opendocument";>here</A>.
If you have LabVIEW 7 or greater, you can ignor the part about
additional drivers required for WinNT and W2K. They are no longer
required.