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Can I communicate with a parallel port using the U3?

parallel port matlab

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#1 kgarcia

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Posted 24 July 2014 - 04:45 PM

Hi all,


I'd like to send signals from a Mac laptop through the U3 to the parallel port on a PC, essentially using the U3 as a USB to parallel converter. It seems to me like I can just cut open a parallel cable and connect it to the DIO ports on the U3. Is this true? Thanks!

#2 LabJack Support

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Posted 25 July 2014 - 11:12 AM

We don't provide any special support for the PC Parallel Port, but a parallel port is basically up to 17 digital I/O, and the U3-LV has up to 20 digital I/O, so you might be able to control the U3 digital I/O in such a way to transfer data to/from the parallel port.


1st you would have to know if the logic levels are compatible with CMOS or TTL.  The U3 digital outputs 3.3V/0V for output-high/output-low, likes -0.3V to 0.8V for an input low, and likes 2.0V to 5.8V for an input high.




2nd you would have to know how to use the control lines to latch in bytes of data.  The book Parallel Port Complete might be useful:



Also tagged with one or more of these keywords: parallel port, matlab

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