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I have a data acquisition application controlled by a Windows PC. I am using an Intel Desktop Board DH67CL motherboard. This has 6 USB2 ports along with 2 of the new blue USB3 ports. The DAQ instrument connects via USB to the computer. Roughly once every day or two there is a short communication glitch with the USB that causes the instrument to disconnect briefly and then reconnect. This is logged so I know whenever it happens. Occasionally it will cause the data acquisition to stop. I've verified that the glitches will go away if I use the USB3 ports, or if I use a PCI add-on card with USB ports.

So it seems that there is something going on with these built-in USB2 ports on this motherboard. I haven't yet had a chance to test with other motherboards.

My question: what could be causing these glitches and how to get rid of them for this board, or is there a better motherboard to use?

We have standardized on the DH67CL because it's inexpensive, has 3 PCI slots that we need, and is readily available. We don't need the power of higher-end server boards but reliability is important.


Update: This problem has been reproduced many times on different hardware, though we always use the same model of motherboard (DH67CL) and power supply (Antec EA-430D). I don't think the power requirements are very high but will check on that.

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Have you tried it with a second, identical model? Maybe the board is broken. Why take a risk? Try a replacement. – Oliver Salzburg May 28 '12 at 22:48

What kind of Power Supply do you have in this computer (wattage)? ANd how much power does your DAQ instrument need to run? Check the specs... certain devices draw more power than a standard usb port puts out.

Or it could be just a bad power supply. I just replaced a PS last week on a computer that was dropping usb connections intermittently. Tested the ps and found out it was failing (Antec Power Tester)

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Have a look if you see anything in the windows eventlogs.

Get to them by running eventvwr.msc from a command prompt or from the search box in windows 7 start menu, or from "Start->Run" dialog in older versions.

If you are on Windows 7 check out Windows-logs -> Application and System, older systems have almost all under Application.

These logs should reveal more details about the root cause of disconnection. If not, or if the info is to meager, you may want to run some Xperf sessions, but that will take quite some effort to learn / set up.

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You might want to try if this problem persists if you connect the instrument through a powered hub, especially if it draws a considerable current. Also check if a better USB cable helps. Cheap cables tend to have reduced gauge on the power wires (saving expensive copper) so there can be significant voltage drops if a device draws higher currents.

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Also, a shorter USB cable or one with a ferrite bead (…) would help immensely. Ferrite beads stabilizes and supresses high frequency noise as a type of electronic choke. – Seth Jeremi Malaki Jun 3 '12 at 23:31

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