Labview 7 and USB control

[Jeff Shama]

Has anybody been able to write to a USB port with LV7? I have a USB to
Parallel adapter that will be used to control a robotic arm. I would
like to use a USB port vice the parallel port, but have had no luck in
finding the proper care and feeding of the USB port. All I need to do
is send the port binary data from 00000001 to 10000000. I can do it
fine with the parallel port but not USB. Any tips or a point in the
right direction would be greatly appreciated.

Thank you

Jeff

[Thomas Json]

I have a USB to serial and it work as a serial port which means that I can use the VISA drivers. Maybe it is the same for You. Look in windows device manager if it shows up there.
TJ

[ScottieB]

Jeff,

I understand that you want to write out of your USB-parallel, but it's not going to be as simple as writing to a normal parallel port. You probably received drivers with your USB-Parallel adapter that allows the adapter to appear as though it is a standard parallel port (like LPT2) under Windows. That is going to be the correct way to do what you are trying to do, as then you can just use it in a VISA write just like a normal port.

The other way, writing out the USB port, requires knowing the manufacturer's device ID, what sort of pipes they use for communication, and what sort of data the adapter expects before it will output a set of bits on the parallel port.

Hope this helps.

Scott B.
Applications Engineer
National Instruments

[Jeff Shama]

Thank you for your input. After some searching, I found that the device
uses RAW mode communication and that I did not have the necessary
information that you described below. I all but gave up on my attempt.
If I understand you correctly, I can still communicate with the device
with a non USB VISA write vi. I'll give it a try.

Thank you again.

Jeff

ScottieB wrote:
> Jeff,
>
> I understand that you want to write out of your USB-parallel, but it's
> not going to be as simple as writing to a normal parallel port. You
> probably received drivers with your USB-Parallel adapter that allows
> the adapter to appear as though it is a standard parallel port (like
> LPT2) under Windows. That is going to be the correct way to do what
> you are trying
to do, as then you can just use it in a VISA write just
> like a normal port.
>
> The other way, writing out the USB port, requires knowing the
> manufacturer's device ID, what sort of pipes they use for
> communication, and what sort of data the adapter expects before it
> will output a set of bits on the parallel port.
>
> Hope this helps.
>
> Scott B.
> Applications Engineer
> National Instruments

[ScottieB]

Jeff,

Good luck in your attempts. Remember that the first step is just to get the device to be recognized as a standard parallel port by your computer, then VISA should see it just fine. Post here or start a new thread in Discussion Forums if you need more assistance.

Scott B.
Applications Engineer
National Instruments

[Jeff Shama]

Thank you for the help.

Jeff

ScottieB wrote:
> Jeff,
>
> Good luck in your attempts. Remember that the first step is just to
> get the device to be recognized as a standard parallel port by your
> computer, then VISA should see it just fine. Post here or start a new
> thread in Discussion Forums if you need more assistance.
>
> Scott B.
> Applications Engineer
> National Instruments