Use of USB-6008 through a USB device server

[andre0]

We are trying to use our USB-6008 through a USB device server (http://www.silexeurope.com/en/home/products/usb-device-servers/sx-ds-4000u2.html).

Everything works fine, except that we are not able to acquire samples from the analog input ports. MAX always says "The specified operation did not completed, becaus the timeout has elapsed" when I push on the button "Execute". (See the attached screenshot).

Thanks for your help.

[cedhoc]

Hi Andre,

We can hardly give you any confirmation that the USB-6008 will work with any USB server, USB extender, USB over Ethernet or whatsoever.

Those devices can induce some unknown/uncontrolled delays on the bus which makes the life difficult for the DAQmx driver to control the DAQ module.

Did you try also the other acquisition modes (finite, continuous) with various sample rate and sample count settings? If all of those tests are not conclusive, then I am afraid you will not be able to use the USB-6008 with the USB server.

Kind regards,

[Process_Systems]

The descriptor page for your Silex device mentiions a USB power-down on non-use function. If you can disable this feature, you will probably have much better luck with the NI USB daq equipment. Most usb devices don't like having power interrupted; it causes them to re-initialize, or sometimes outright hang up. I have used a USB server from B&B Electronics in an app like yours, and it works fine (no auto-power  down feature to deal with).

My two cents, for what it is worth.

Have a nice day,

Dave

[andre0]

Cédric,

Thanks for your answer. Yes, we tried all the acquisition modes, but none of them allowed us to acquire data from the device's input ports. I guess we'll have to check for another device server, or go to a full ethernet solution...

Regards,

André.

[andre0]

Hello Dave,

We indeed saw that option in the device config, but it was always unactivated.

With your B&B device, did acquisition from the analog input ports work ? With what configuration (mode, sampling frequency, etc.) ? Could you give me a pointer to the device ?

Thanks a lot,

André.

[Process_Systems]

I just took a look at the B&B site, and the closest they now have is the UE 204. I can't remember the model number of the one I used; it was a few years ago, but they seem to have discontinued it. At any rate, it had a device driver that you install before firing up Labview, and then the USB pots on the extender were addressed directly as if they were part of the PC. I used an NI USB multipoint DAQ unit, and had no troulbe ( I think I had 21 or 22 analog input points, but it was some time ago, and the memory escapes me).

Good luck with your project,

Dave