1 - Installation [U3 Datasheet] | LabJack
« Close

Datasheets and User Guides

App Notes

Software & Driver


1 - Installation [U3 Datasheet]


The LJUD driver requires a PC running Windows. For other operating systems, go to labjack.com for available support. Software will be installed to the LabJack directory which defaults to c:\Program Files\LabJack\.

Install the software first by going to labjack.com/support/u3.

Connect the USB cable: The USB cable provides data and power. After the UD software installation is complete, connect the hardware and Windows should prompt with “Found New Hardware” and shortly after the Found New Hardware Wizard will open. When the Wizard appears allow Windows to install automatically by accepting all defaults.

Run LJControlPanel: From the Windows Start Menu, go to the LabJack group and run LJControlPanel. Click the “Find Devices” button, and an entry should appear for the connected U3 showing the serial number. Click on the “USB – 1” entry below the serial number to bring up the U3 configuration panel. Click on “Test” in the configuration panel to bring up the test panel where you can view and control the various I/O on the U3.

If LJControlPanel does not find the U3, check Windows Device Manager to see if the U3 installed correctly. One way to get to the Device Manager is:

Start => Control Panel => System => Hardware => Device Manager

The entry for the U3 should appear as in the following figure. If it has a yellow caution symbol or exclamation point symbol, right-click and select “Uninstall” or “Remove”. Then disconnect and reconnect the U3 and repeat the Found New Hardware Wizard as described above.

Figure 1-1. Correctly Functioning U3 in Windows Device Manager

Linux and Mac OS X

The Exodriver is the native USB driver for Linux and Mac OS X. With it you can use low-level functions to interact with your U3 over USB. The LJUD driver, LJControlPanel and LJSelfUpgrade applications are not available for Linux or Mac OS X.

Download the Exodriver at labjack.com/support/software or labjack.com/support/linux-and-mac-os-x-drivers. For Mac OS X you can use the Mac Installer for installation, otherwise use the source code and install script.

Mac OS X Installer

Unzip the contents of Exodriver_NativeUSB_Setup.zip and run Exodriver_NativeUSB_Setup.pkg. Then follow the installer’s instructions to install the driver.

Source Code

Mac OS X Requirements

  • OS X 10.5 or newer
  • Xcode developer tools
  • libusb-1.0 library available at libusb.info

Linux Requirements

  • Linux kernel 2.6.28 or newer.
  • GNU C Compiler
  • libusb-1.0 library and development files (header files)


To install the driver from source code, first unzip the contents of the Exodriver source code. Then run the following commands in a terminal (replace <Exodriver-Source-Directory> with the directory you unzipped the Exodriver source code to):

    cd <Exodriver-Source-Directory>
    sudo ./install.sh

Follow the install script’s instructions to install the driver.

For more Exodriver installation information go to the Exodriver page at labjack.com/support/linux-and-mac-os-x-drivers. The source code download’s README, INSTALL.Linux and INSTALL.MacOSX also provides more information. If you run into problems, first take a look at the comments section of the Exodriver page as the issue may have been helped with previously.

After installation, to test your U3 connect it to your computer with a USB cable. The USB cable provides data and power. Build and run one of the examples from the source code download. Alternatively, install LabJackPython (at labjack.com/support/labjackpython) and run one of its examples.


Dear support team,

Im trying to install the U3-HV on windows 7, I have done all that is indicated, and I have repeated again and again, but windows don't recognize the hardware, what else can I do?

So you are having some problem at step #2 here of the quickstart on U3 Support Homepage?

Windows complains about something?  What do you see in Windows Device
Manager as you connect/disconnect the U3?

Do all initial troubleshooting with nothing connected to the U3,
except USB as needed.

Is this a new U3?

Section 2.2 describes typical power-up behavior of the LED.  Please
describe what you are seeing.

Try a different USB cable.

Try a different computer.