using USB to communicate LabView with Agilent instruments

[lele]

I'm not used to USB comunication protocol, but I need to use LabView to communicate with some USB devices.
What do I need to know (basically)?
I have LabView 6.1 installed under Windows 98 (somebody recommended me "hid.dll" windows library , but I have no extra information about that). Thanks!

[Ray.R]

Hi Lele,

I have a number of USB intruments that are controlled through LabView. However, all of these instruments either have Labview drivers or API's (dll's).

The fact that you have Win-98 may make things a little more tricky. I seem to remember that Win-98 Second Edition either had or could have USB support. I cannot remember if there was a patch for the original Win-98, but you can check MS website for that info.

Basically, here is what you need to know:

1. Which version of WIn-98 do you have?
2. Is the USB support drivers (for the OS) installed?
3. Install the drivers or sw that came with the USB instrument.
4. Find out if there are LV drivers or API for the product. If so, check to see if it came with an example (even a poor example i
s better than none).
5. Try communicating with the instrument by using the interface sw provided by the manufacturer first (Agilent's sw in your case). You will want to do this to "debug" the installation before you attempt automating it with Labview... (baby steps - very important).
6. Once everything seems ok, then proceed with the Labview code.

The behavior of the USB device may become erratic if you disconnect and connect (or connect into a different USB port). So be careful with that.

Other than the above, I recall that USB was as simple to interface as GPIB. Maybe I was lucky?? Hopefully, you will be, too.

Hope this helps..

JLV

[Dennis_Knutson]

Just to add to what Joe said, first make sure you're using the latest version of VISA. USB instrument support was added in version 3. Then, if you have a driver for the instrument that uses VISA calls, then all you should have to do is enter the correct VISA Resource Name. Make sure that the USB instrument shows up in MAX. It should if the OS has USB support installed.

[rolfk]

JoeLabView wrote:

> Hi Lele,
>
> I have a number of USB intruments that are controlled through LabView.
> However, all of these instruments either have Labview drivers or API's
> (dll's).
>
> The fact that you have Win-98 may make things a little more tricky. I
> seem to remember that Win-98 Second Edition either had or could have
> USB support. I cannot remember if there was a patch for the original
> Win-98, but you can check MS website for that info.

Windows 98 should have USB support. It is Windows 95 which didn't and
you needed to install Win 95 OSR 2.1 to have USB support but that
typically messed with my system so much that it almost everytime got
unusable after a few weeks.

Rolf Kalbermatter

[Ray.R]

Hi Rolf,

Yes, I you are right. I remember people having many problems. I thought the original Win-98 was also problematic with USB... maybe I'm wrong... it is now a long time ago.

JLV