Getting started with the LabJack U12 in LabVIEW
Posted 04 August 2003 - 12:58 PM
The first thing to realize is that NI-DAQ is primarily for National Instruments DAQ boards, and thus to talk to the LabJack U12 you need to use our functions, and not the DAQ functions from the "Data Acquisition" palette in LabVIEW. Similarly, the NI application called Measurement & Automation (MAX) is pretty much a user interface for NI-DAQ and also has no use with the LabJack.
We have VIs that call all the functions declared in Section 4 of the LabJack U12 User's Guide. The user's guide documentation is written in C, but the VIs are very similar.
Keep in mind that our software can be downloaded at any time from labjack.com. Since most of the driver functions have a demo input, the VIs can be evaluated without hardware:
The LabVIEW drivers are in ljackuw.llb, and these drivers call functions from our DLL which is placed in the Windows system directory.
If our installer detects LabVIEW on your computer, it will place the LabJack drivers in the proper directory such that you get a "LabJack" sub-menu on the LabVIEW function palette. If you have more than one version of LabVIEW installed, the LabJack drivers are copied to the directory of the version that Windows considers "current". To manually install the drivers, you can copy the "LabJack" directory from:
and place it under \vi.lib\addons\ in your LabVIEW directory. If you do not have an "addons" directory create it.
The normal LabVIEW drivers are best for LabVIEW 6.0.2 or higher. If you have LabVIEW 5.X, use the drivers located in:
If you look in the LabJack directory under \examples, you will find some simple LabVIEW examples and source code for most of our sample applications (LV 6.0.2). Some of our examples (particularly LJlogger) use VIs that are not included with the base version of LabVIEW. If you are missing some VIs used by our examples (such as SMTP, FTP, and report generation), you will have to delete that functionality from the example.
See the following topic for another simple example concerning analog output:
The normal LabVIEW drivers in LabJack software V1.17 have been tested in LabVIEW 6.0.2, 6.1, and 7.0. Note that LabVIEW 7.0 requires LabJack drivers V1.17 or higher. Run LJtest to see your driver version, and download the latest drivers if needed:
Sometimes people make a copy of the LabVIEW drivers and put them in various places. If this could be the case on your PC, search for and delete/archive all copies of the drivers (ljackuw.llb) before running our installer.
If you develop a VI in LabVIEW 5.x using our LV5 drivers (ljackuw50.llb), and then upgrade to LabVIEW 6+, your VI will still be calling the 5.x drivers from ljackuw50.llb. The easiest way to solve this is to search for and delete/archive all copies of the 5.x drivers (ljackuw50.llb). Now when you next open your VI, it will prompt for location and you can tell it to look in ljackuw.llb.
Posted 17 December 2003 - 10:40 AM
Posted 13 February 2004 - 09:57 AM
Posted 17 May 2004 - 07:33 PM
The 2/13/2004 post on Labview Student Edition does not say which version is being discussed. Is Labview 7 Express Student Version compatible with LABJACK? In the functions pallet, the Call Library, Code Interface Node and ActiveX functions are not grey'd out, implying that they will work?
From what we understand, all the LabVIEW functions that allow access to external code are disabled in the student edition. This would include "Call Library", "Code Interface Node", and ActiveX stuff. This would make it quite difficult to access our products from the LV student edition.
Posted 18 May 2004 - 08:22 PM
Posted 20 July 2004 - 11:21 PM
Posted 26 April 2005 - 08:54 AM
Posted 10 October 2006 - 11:56 AM
Posted 17 February 2007 - 05:32 PM
More detail about the function palette. First, don't let it stop you if you have trouble getting the U12 functions to show up on the function palette. Sometimes this is convenient, but it is not a necessity at all. Different versions of LabVIEW and different computers can be quirky about how to get things in the LabVIEW palettes, or where they show up in the palettes, but you can always just use the "Select a VI ..." item on the function palette (looks like a cartoon dialog balloon). In LabVIEW 7 this is under "All Functions" on the function palette. Doing this brings up a dialog box, and you can browse into ljackuw.llb and select the function you want to put in your VI.
If the U12 installer can read the registry entry specifying the "current" LabVIEW installation, it will put the needed files in place so that LabVIEW should display the U12 functions on the palette. For example, with LabVIEW 7.1 you should wind up with the following two files in the following locations:
c:\Program Files\National Instruments\LabVIEW 7.1\vi.lib\addons\LabJack\dir.mnu
c:\Program Files\National Instruments\LabVIEW 7.1\vi.lib\addons\LabJack\ljackuw.llb
LabVIEW must be restarted after the files are placed in those locations. Then if you go to the block diagram of any VI, bring up the function palette, and select "All Functions" (LabVIEW 7), you should see an item labeled "LabJack U12 Legacy".
Note that "current" LabVIEW installation likely means the last-installed version, not necessarily the latest version.
Posted 23 October 2013 - 09:35 AM
We have heard some reports of the U12 function palette just showing up with question marks. We have found that if you are using the LabVIEW71_LJUD archive you have to rename the folder to LabVIEW_LJUD in addons, then run LabVIEW and see if it loads it properly.
Posted 16 January 2014 - 12:46 PM
I am trying to use a U12 I got from a coworker, and I downloaded the drivers and labview vi's from the website, but seem to be missing labjackm.dll.
Posted 16 January 2014 - 03:55 PM
I believe you downloaded the wrong set of labview vi's, if you are requiring the labjackm.dll you likely picked up the LJM LIbrary vi's. Instead you should use the U12 Library vi's found here:
Also, make sure you have downloaded the correct U12 Installer found here:
Posted 11 May 2015 - 09:44 AM
Hello, I just bought a couple of Labjack U12 to use with Labview 2014. But after installation of the U12 driver only the
examples are installed and not the labview\vi.lib\addons. Should U12 support this Labview version?
Posted 11 May 2015 - 10:27 AM
Are you referring to post #9 above? Try searching your entire machine for "ljackuw.llb" and see where it got put.
Posted 11 May 2015 - 11:42 AM
Hi again, I found the ljackuw.llb under windows/system32 then I copied into a new folder as described in post#9 but the file "dir.mnu" I can't find
and I don't know if it's needed or not. But when trying the exemples called "Simple example" it complains that
it's missing 3 subVI: "GetErrorString.vi", "AOUpdate.vi" and "AISample.vi".
Posted 11 May 2015 - 12:45 PM
Hello, for some reason when running the "LabJack-U12-Installer-2015-03-27" the "ljackuw.llb" isn't installed. So after
googling the file and saved it into the addon folder as in post#9 it worked.
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