read and write to the printer port

[Donkey Rubarb]

Hi there,

I am having trouble using the printer port with Labview 6.1 on a WIN XP and WIN 2000 Pc.
I installed the Access HW as indicated somewhere on this site.
The out port.vi seems to work, but the problem is the In port.vi. LV stops running when it comes to the In port.vi and gives the following error message: Capability not supported...
so the same error as if Access HW is not installed.
???
Could there be a reason why out port.vi would work and in port.vi not?
Also I am not able to use the out port vi after the error I just described.
Reinstalling Access HW lets me use the out port vi again but the input vi seems to cause the same problem time after time after time.

I want to use the in port to read data from the s
tatus register, I supplied the vi with the correct adress and I dont know if there is anything else I can do.
Maybe you do??

[FightOnSCTrojan]

Hello f_d:

I have been performing I/O functions with AccessHW (with Win 2000 Pro), and I have not had much problem.
Although I will be able to better answer your question if you actually attach your program, here are the things that I could come up with, after reading your problem description:

1. Since you were able to use outport.vi in the first run, and not after you use inport.vi, I will suggest you to replace the outport and inport.vi of the Labview user.lib (normally located at C:\Program Files\National Instruments\LabVIEW 6.1\vi.lib\platform\system.llb), with the new ones (use save as after a fresh reinstallation). This way, you will always get the AccessHW vi that supports Kernel mode routines. I used VIs from the latest AccessHW.vi (_LV5)


2. While accessing the Status Registers, did you use base address +1?
3. While accessing the Status Registers, did you write true (read word) top inport?
I am thinking that more likely, your problem is due to #1. But you are more than welcome to share your vi with us, so we can help you to debug.

SCTROJAN

[Ben]

Another thought;

Not all parallel port are bi-directional.

Ben