How are the RAW USB vi.s used? For instance, how do you specify which pipe data will go through?

[LabTech]

How are the RAW USB vi.s used? For instance, how do you specify which pipe data will go through?

[Doug M]

LabTech,
This depends on what type of pipe you are communicating to.  First, please see the following resources on our website: Using NI-VISA 3.0 to Control Your USB Device, How Can I Communicate With a Device Using NI-VISA USB RAW Mode?, and Why Do the NI-VISA USB Specific Attributes Not Appear in LabVIEW Property Nodes?.

You may also want to check out the VISA Programmer's Manual.

For control pipes, currently VISA only supports the default endpoint with address 0x00.  For Bulk or Interrupt pipes, you can set the pipe address using a property node.  To get to the property node for VISA USB, see the KB linked above.  Then you can use the properties USB Bulk-In Pipe, USB Bulk-Out Pipe, USB Interrupt-In Pipe, and USB Interrupt-Out Pipe.  For Write or Read to or from a Bulk pipe, just use the VISA Read and Write VIs.  To read from an Interrupt pipe, also use the VISA read VI.  As of VISA 3.3 Writing to an Interrupt pipe is not supported.  To write or read from the default control pipe, use the VISA USB Control In and VISA USB Control Out VIs.

Hope this helps!

[LabTech]

Thanks for the reply. The code for the Microchip Dev board indicates it transfers data through a USB interupt transfer. I can get manufacturer and other information from the board, but the interupt pipe returns -1, indicating that there are no established interupt pipes. Any ideas?

[Doug M]

As a follow up to my last post, I mistakenly said that writing out to an Interrupt pipe was not supported.  This is supported starting with NI-VISA 3.3.  As for why you aren't getting data, the USB spec is pretty loose and implementations are very device specific.  The best resources I know of are the ones I linked to in my previous post.

[zyu]

I have one problem for help: Why I can't see "USB interrupt-Out Pipe" in property node when use VISA 3.5?

Before I install VISA 3.5, I use Labview 7.1 and VISA 3.2, I found the "USB interrupt-Out Pipe" is not supported. It is said that this setting will

be supported by VISA starting with 3.3 version. So I upgrade VISA 3.2 to VISA 3.5, But I still can't found the setting "USB interrupt-Out Pipe". I am confused.

I don't know why the setting "USB interrupt-Out Pipe" is not provided when I use VISA 3.5.  I don't know whether it is related with low version labview 7.1 or the INF file which is generated by Driver development Wizard of VISA 3.2.

Anyone can help?

[Chris_R.]

Hi Zyu,

The name of this property changed in VISA 3.3.  It is called "USB Out" now.  Be sure to first select the correct VISA Class (see second screenshot) and the "USB Out" should be an option for you.  Please let me know if you have any trouble!

Have a great day!

Message Edited by Chris_R. on 06-06-2006 06:13 PM