The most common error that occurs with the LabVIEW examples for LabQuest is a problem with the driver and/or the DLL file to communicate with the driver.

At the heart of the LabVIEW examples for LabQuest are subVIs that use LabVIEW’s Call Library Function Node to communicate with the LabQuest. This LabVIEW function is a way to access our Dynamic Link Library (DLL). The DLL file, in turn, communicates with the LabQuest driver.

The most common issue with not being able to get the LabVIEW examples to talk to LabQuest are either a problem with the driver or a DLL file that is incompatible with the driver that is installed. Try the following steps in order.

1. Update your Graphical Analysis app and Logger Pro software to the latest version.
There have been several iterations of the LabQuest driver. Update your Vernier software in order to install the latest driver.

*Updates to Logger Pro are free and can be found here:
*Updates to Graphical Analysis are also free, but are initiated from within the app. From the menu in the upper-right corner of the app, choose “Check For Updates” and, if necessary, update the app.

2. Test the driver.
Open Logger Pro or Graphical Analysis. Does it find and communicate with the LabQuest? If yes, then the driver is good. If not, see: Are the device drivers installed correctly? (For Windows with LabPro, original LabQuests, LabQuest Mini, and LabQuest Stream)

3. Update your Vernier LabVIEW VI files for LabQuest to the latest version.
We periodically update our LabVIEW files in order to keep up with the changes in the LabQuest driver. Reinstall our LabVIEW files from LabVIEW Downloads

At this point, LabVIEW should be able to run the LabQuest example VIs. Open one and verify that it is working. If it does not, check the following:

A. Confirm the DLL file is in the correct directory.
The DLL file is part of our LabVIEW files that should be in your National Instruments/LabVIEW 20xx/vi.lib/Vernier/LabQuest directory. There is a folder called LQ DLL that has the DLL file used by LabVIEW. Confirm that the file called NGIO_lib.dll is in your LabVIEW directory.

B. Confirm that the DLL file is the correct DLL file.
There are two versions of the NGIO_lib.dll file. The difference in the two files is that one is used with 32-bit LabVIEW and one with 64-bit LabVIEW.

First, you need to find what version of LabVIEW you are using. Open LabVIEW and open the About LabVIEW menu item. Look closely to find where it says 32-bit or 64-bit.

Next, confirm that you are using the right NGIO_lib.dll file. Currently, the dll file for 32-bit LabVIEW is 3,215 KB in size. The dll file for 64-bit LabVIEW is 5,159 KB in size.

If you have the wrong dll or you can’t find any LabQuest files in your LabVIEW directory, then you should run our LabVIEW installer again and see if it places the files correctly. The LabVIEW installers can be found at LabVIEW Downloads

If LabVIEW still does not run the LabQuest example VIs, call Vernier Tech Support for additional help.

National Instruments LabVIEW Troubleshooting and FAQs