There is a problem with some high-speed USB connections on computers running Windows 7. This is a problem especially with laptop computers. The symptom of this problem is that your LabVIEW VI, or the Analog Express VI, will read from an analog sensor for a few seconds and then lose communication with the sensor. Unplugging and then reinserting the USB cable into the computer will fix communication with the sensor, but again, for only a few seconds.

Depending on what example you are running you may, or may not see error (-200474).

The fix:
First, check the installed version of DAQmx software. If it is not 9.4 or higher, download the latest version from the National Instruments web site (www.ni.com) and install it.

Then, get the latest version of the Vernier LabVIEW files for SensorDAQ. You can download the LabVIEW files from here: https://www.vernier.com/engineering/ni-labview/downloads/sdaq/

If you are using an old version of our LabVIEW files for SensorDAQ and do not update to the latest version you will need to manually replace a file, following these instructions:

Download the VI called SensorDAQ_ConfigAITask.vi which is attached. Copy this to the Vernier files in the LabVIEW directory to replace the old SensorDAQ_ConfigAITask.vi. Find this file in the LabVIEW directory at
C:\Program Files\National Instruments\LabVIEW 20XX\vi.lib\Vernier\SensorDAQ\Low Level Drivers\SensorDAQ subVIs.
If it is a 64-bit computer, the LabVIEW directory will be found in Program Files (x86).

http://www2.vernier.com/labview/win/SensorDAQ_ConfigAITask.vi