06-16-2014 12:05 PM
Apologies in advance if this has already been asked, but I couldn't find it in a search.
We use USB-6009s to measure one analog signal. We recently purchased the latest model of the laptop we have been using, and with this new laptop model we observe that the USB-6009s stop working after a short while (usually less than an hour) of taking data. Although the time to failure is variable, once the USB-6009 stops working it doesn't work until we un-plug/re-plug the USB cable to the laptop.
Is this behaviour consistent with the device not being supplied enough power through USB? Is there a way to verify whether this is what's happening? We are wondering if the new laptops are not up to the task, and are going to try a powered hub as an experiment.
Solved! Go to Solution.
06-16-2014 12:22 PM
I've continued searching in the forum and found this post and I'm going to try the suggestions there. Any other feedback definitely welcome!
06-16-2014 12:24 PM
Go into the Device Manager on your Windows laptop. Find the USB hubs in the list and go to their properties. There is a "power saving feature" where Windows will turn off the USB bus power. Disable that.
06-16-2014 02:27 PM
Thank you for your help crossrulz. I found that my USB 3.0 Root Hub had the option checked to allow power savings, although the USB 2.0 Root Hub was unchecked. Since I was already using a USB 2.0 port for my NI 6009, this unfortunately didn't help the problem, although it's definitely a good thing to have fixed!
My next steps are to try a powered USB hub and/or to install the latest DAQmx software (we are at 9.32).
Suggestions still welcome. I will do my best to remember to update with my results checking with the powered USB hub and the latest DAQmx software.
06-17-2014 10:03 AM
You are going in the right direction. Your initial post exactly discribes a USB port loosing power. That could be the power manager settings, a weak or poorly regulated supply or potentially a ground loop or even high noise.
A Good quality USB HUB with a sufficiently well regulated supply is a must!
Good quality cable are a must and do you have ferrites on the cable?
Last - since you mentioned "Laptop" how are you referencing that laptop with respect to the earth ground in your test setup? NOT just through the USB Shield right? That would be bad.
06-18-2014 04:58 PM - edited 06-18-2014 04:59 PM
So it looks like the main cause of our problem was an old DAQmx. We have been using v9.2.3
I waited 'til the 6009 got into the no-longer-acquiring mode, and then tried to use a Test Panel in Measurement & Automation Explorer. It gave me an error about buffer overruns. When I checked the DAQmx release notes (especially for v9.4, and for v9.6 ) I found several 6009-specific fixes related to buffer overruns and Windows 7 compatibility, so I installed the latest DAQmx, v9.9.
Although I haven't done conclusive testing, the problem I was seeing seems to have gone away after installing the latest version of DAQmx.
Why did this happen on our new laptops (Dell 5540) and not the old ones (Dell 5530) using the same Windows image? I'm not sure, but can only assume the older NI drivers didn't play well with the new systems' chipset/USB drivers.
Thank you everyone for your help!