06-05-2012 05:32 AM
Hello,
I'm having some trouble using usb devices with Labview. According to what I've read, the plugged usb devices should appear in MAX under "devices --> usb", but I don't have such "usb" subsection.
I have installed the instrument drivers supplied by the manufacturer (I can use the instruments with their own control software) as well as the instrument drivers for Labview. I also have NI-VISA installed.
What am I missing?
Thanks.
06-05-2012 09:29 AM
You have not provided hardly enough information. Exactly what USB devices? What exactly did you read?
06-05-2012 09:46 AM
I've been trying with a Newport 1900 power meter and an Ocean Optics QE65000 spectrometer.
I started here.
I'm running Win7 32bit and LabView 2009, NI-VISA 5.1.2.
Thanks.
06-05-2012 09:53 AM
The only USB devices that will appear in MAX are USBTMC, serial port emulators, and devices for which you write your own driver. Check in device manager to see how the devices are enumerated. Then look at your LabVIEW drivers. If they use a Call Library Function Node, ActiveX, .NET, then you should not care whether they appear in MAX or not.
06-06-2012 03:55 AM
Thanks for your reply.
The trouble is that the labview drivers for the Ocean Optics spectrometer include an "initialize" VI that expects a "visa resource name" in order to know which instrument to address. In the dropdown list for the visa resource name I have COM ports, an LPT1 port, and the devices I have attached to the gpib card, but nothing USB.
Since the instrument drivers expect a visa resource name, I would expect the usb interface to appear in that dropdown list somehow, but it doesn't.
According to this, it doesn't seem I should need anything that I don't already have, so I must be doing something wrong.
06-08-2012 05:04 AM
I found the problem. I'll post it here in case that might be useful for other people.
It turns out the Labview drivers for the OceanOptics spectrometer cannot coexist with the drivers that allow you to use the spectrometer with Spectrasuite (Ocean Optics' own software for controlling the spectrometer). That means that either you use the spectrometer with Spectrasuite or you use it in Labview (which is pretty bad honestly).
Next, it seems that, at least in Windows 7, when you install the Labview drivers you basically download the VI's, but the driver itself is not installed. You have to manually go to the device manager in Windows, select the Ocean Optics spectrometer, go to "update driver", and manually select the .inf file located in the folder of the Labview drivers (by default something like program files -> national instruments -> labview2009 -> instr.lib -> ocean optics 2000 4000).
Once you do that, the spectrometer will not work with Spectrasuite anymore, but in Labview you get a corresponding visa resource name to address the device.
For a plug&play, easy to use and intuitive system, this whole business is pretty messed up in my opinion. But oh well...
Thanks for your interest.