Set-up two USB-6008 through USB hub

[fguiz]

Hi,
I want to use two USB-6008 to drive a piece of electronic. These two boxes will be connecting to the PC through a USB hub.
The I/O are specifically set-up for each boxes (eg current setpoint on box#1 pin 14).
When plugging the hub, it seems the boxes are reconnized as box#1 or box#2 randomnly.
How can the program be set-up so that it knows which box to consider as box#1 and box#2?
Thanks

[Nicholas_B]

Greetings fguiz,

Try plugging them into your hub in a specific order.  For example, the first device plugged in should be recognized as "Dev 1" each time and the second as "Dev 2"  Please let me know if this makes a difference...

Regards,

Nicholas B

National Instruments

[fguiz]

Hi Nicholas,
Thanks for your reply.
This does indeed recognize the two boards in a given order. But, I am planning to use the two USB-6008 in a little box with a hub enclosed so that the user connects its PC to the hub.
Thus the two USB-6008 will always be connected to the hub, and the user will only connect to the hub and thus will not be able to connect the USB-6008 one by one.
Do you have any other ideas?
Fabien

[Nicholas_B]

Hi Fabien,

Here is what you can do:  use the attached VI to extract the device information for all of the DAQmx devices connected to your system.  Then we can match up the serial number field with the serial numbers on your USB-6008 devices to find out which one has been assigned to Dev1 and which one has been assigned to Dev2 (use a case structure to perform this in LabVIEW...pass the serial number to the case selector and feed the device numbers into the cases, extracting the proper one each time).  You can call this piece of code in the beginning of your existing code to determine which USB device corresponds to which DAQmx device number, then you can feed the right device number from the case structure to the portions of your code that perform the I/O. 

That should work for you!  Let me know if you have any questions...

Regards,

Nicholas B, National Instruments