DAQ reading zero intermittently

[pjr1121]

I am using 3 analog inputs of a DAQ USB-6009 to monitor and record temperatures of my system.  This VI runs continuously performing 1 read per second and periodically saving values to file.  Everything works great for a couple weeks, or even a few months, until the DAQ reads suddenly have a value of zero.  unpluging the DAQ and plugging it back in solves the problem.  As such, I am assuming it is due to a power cycle of the DAQ or perhaps the USB communication being refreshed that I receive the correct values again.  Any ideas on how to test for the cause of this issue or some preventative steps I can take?

I was thinking closing and re-establishing communication at the end of each day might help.

Oh, and I'm using LabVIEW 2010 on Windows 7.

[crossrulz · Accepted solution]

Turn off the "power saving feature" of Windows 7 where it randomly turns off your USB hub.  Go into the Device Manager and go to the USB hubs and then into the power settings.

[pjr1121]

Thanks,

Since I had the Windows power management options turned off I hadn't considered separate power settings for the USB.