Communicating USB using Labview VISA

[sf5959]

Actually, that is not the case. It is indeed a USB RAW device. I have spoken with the manufacturer on this. In fact, when I first plugged in this device, it installed itself as any normal USB device will in Windows. I had to uninstall the device and create the drive using the VISA wizard. This was done successfully and I can get Labview to open the port and initiate communications with the device. I am not having success with sending over the individual commands from the manufacturer's command set. The issue is not with the Thermo device, the issue is with getting Labview to talk to it. Now, as I have said before, I have not used Labview to communicate USB and this is where I need help.

[smercurio_fc]

The documentation you provided is for a serial interface, not a USB RAW device.

[sf5959]

No, that documentation is for both. Believe me, I have asked.

[Intaris]

Believing you would be silly because you're plain mistaken.

USB does not have a Baud rate.  It doesn't have parity, stop bits or all that jazz listed in your communications document.

IT has endpoints, configurations, bulk, control, interrupt and isochronous communication.  None of these are mentioned in the document.

The device is a USB device which installs itself as a vritual COM port so that you can communicate with SERIAL communications (the non-universal kind).  It's quite common.

If Thermo telly you it's a RAW USB device then they don't know their products at all.

Use the default manufacturer's drivers and use plain old serial communications.

Shane

[lmtis]

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@sf5959 wrote:

Hello Chris, I do not receive any errors and yes, I am including the termination characters in the string.

Here is what I get when I use a USB port monitor when I send out this string.

Thanks!!

[94] URB_FUNCTION_BULK_OR_INTERRUPT_TRANSFER (SUCCESS/0x00000000) 20101119150318.131 (+0)
Pipe handle: 0x87696D6C
Transfer flags: 0x00000002 (USBD_SHORT_TRANSFER_OUT, USBD_SHORT_TRANSFER_OK)
Transfer buffer MDL: 0x88C47208
Transfer buffer length: 6
Bytes transferred
0x0000: 52 20 53 50 0D 0A (R SP.. )

---

[94] URB_FUNCTION_BULK_OR_INTERRUPT_TRANSFER (SUCCESS/0x00000000) 20101119150318.147 (+16)
IRP status: 0x00000000 (STATUS_SUCCESS)
Pipe handle: 0x87696D6C
Transfer flags: 0x00000002 (USBD_SHORT_TRANSFER_OUT, USBD_SHORT_TRANSFER_OK)
Transfer buffer MDL: 0x88C47208

---

In the bytes transferred it indicates that you actually sent the letters S and P in your command.  I believe that you should have sent: 52 20 0D 0A.  <SP> means "put a space here".

[sf5959]

Okay okay, LOOK. IT IS A USB DEVICE. This device does NOT install itself as a virtual com port as I am fully aware that many do. I have worked with these devices as well. Pay no attention to the portion of the document that references the baud rate, etc. That information is for use with an RS-232 port, OBVIOUSLY. The commands, which I have verified with their design engineers, work over both serial and usb. Some of their products come with RS-232 ports and other with USB. The command set is the same for both.  I am also aware that the documentation is not helpful really at all, I just posted it because it was requested.

Please, I am requesting information that will help me with getting the usb stuff to work within Labview. I would really appreciate anyone's help in this. Thank you!

-Jeremy

[sf5959]

Jim, thank you for your response, I really appreciate it. I understood what the <SP> stands for as they describe the string format, but the command I was sending down was literally "R SP" which stands for "read - set point".  If you take a second look at the string I sent down, the 20hex of the string 52 20 53 50 0D 0A (R SP.. ) is that required space.

[Intaris]

Well then is it a set of commands for a control endpoint, a bulk endpoint or what?

The information you have provided is NOT enough to interface over USB.  Unless you've got other information you haven't shared with us it's going to be difficult to help.

Shane.

[Intaris]

Do you have a full device descriptor for the device?

[lmtis]

DOH!  Guess  I should have scrolled down a bit to see the command listing.