parallel port problem

[tzviel]

I wanted to test my parallel port so, I have made a very simple program that indicates if there is a change of only on bit using the parallel port.

On my computer it works with no problem,even when I made it to EXE file, but when I took the EXE file to use on another computer

the program worked (no errors) ,but it looked like the connection to the parallel port didn't work -  I took one pin and connected it to the ground and there was no change. also I saw that on my computer pin 13 starts as '1' as idle and when i connect it to ground it goes to '0' but on the second computer it starts on '0' and doesn't change.

Does someone have an idea what the problem is?

maybe there is a problem with the driver to talk with the port using labview ? - I use windows xp.

thanks for the help

[jcrooke]

It sounds like the ports may be configured differently on your target machine than it is on your development machine.   It is possible that the address of the port is different on the two machines.  Are you using VISA or the InPort and OutPort vi's?

[jcrooke]

One more thing to consider.   It is necessary on many versions of Windows to install the accessHW drivers (search for them on the NI site) to allow access to the parallel port.  If you found it necessary to do this on your development machine, and your target machine is using the same OS, you will have to install them on the target machine as well.

[tzviel]

I am using the in-port.vi like there is in the parallel port read write.vi example.

I have installed the driver -but on the installation I didn't know which to choose (C++,Borland ...) there was no LabView check -I checked C++.

the in-port.vi in my program and the one in the AccessHW driver are the same.

The address of the port I used is correct.

so, still no resolved...

[jcrooke]

What OS are you using on the development machine?

What OS are you using on the target machine?

[jcrooke]

It occurred to me that there may be nothing wrong with your program.  You have diagnosed the problem by determining whether or not the input pin 13 goes low when you ground it.  Pin 13 is by default configured as an input.  It's state is indeterminant when disconnected.  In order to know its state, you must first force it high or low.  You have forced it low in your test, but since its initial state was indeterminant, you cannot predict whether or not it should have changed.  You should drive it high to see if your program will read the change.

If you attach a sample of your code, I can make a better assessment of what you may or may not be doing correctly.  The following link provides a good description of the parallel port pin-out.

http://www.hamhud.net/ka9mva/regpins.html