Using parallel port

Question

Hi, i will use labview for my thesis project and i plan to input my data via parallel port.
My input data is 8 bits so i tried to use control and status lines of the parallel port.
I used the method that is described at NI`s developer zone web page which shows using control and status lines.
http://zone.ni.com/devzone/conceptd.nsf/webmain/72​c6fc6ce4ad4d1386256b1800794596?OpenDocument
By using that method i achieved to input first 4 bits of my data over status lines while there were no change at those of control lines.
Because my data that i want to input consists of 8 bits, i could only be able to manage half of it.
what can i do for using control lines?
Or as a second alternative, is there any way to input 8 bits over data register?
Below i have attached the code that i had written to input by using control and status registers.
Attachments:
can1.vi ‏30 KB

Answer 1

Well, I looked at your VI and it looks like you have everything setup right. The only thing I can think of is that you are not grounding the control lines when you want to set them low.
As far as your second question is concerned some parallel ports can be bidirectional. The article that you provided explains how you can test if you parallel port is bidirectional, and gives an example on how you would read and write from the data bits.
Also, you may want to try the two parallel port shipping examples in LabVIEW. There is one that uses the data bits, and one that uses the status and control registers. You can find these examples by going to Help>>Find Examples, then search for Parallel.
Shawn B.
National Instruments
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