« Close

Datasheets and User Guides

App Notes

Software & Driver


U3 Base Class in Linux

Carl Friis-Hansen provides a C++ class with a high-level interface to the Exodriver.

Notes from Carl:

The u3Base class provides for:

  • Boolean equations to determine the logic functionality of the LabJack U3.

  • Analog input have lower and upper limits to trigger logic events.

  • All logic, both input and output, has intelligent delay timers.

  • Software switches for manual stimulation of boolean equations.

  • Incorporation of counters into the boolean logic for automatic operations.

  • And a lot more...


For users upgrading to this new version will have to change the instantiation call as the path to the LabJack device has changed into a numeric number.

So the call should be something like:
u3Base u3b( 1 ); // Construct the class to interface to U3 number 1

Individual and youngest files are available at:


Hello, what is the password for the svn repository?

I removed the link that required logging in.  The recommended link to the Subversion repository is http://svn.fiskeryd.com/websvn/listing.php?repname=u3base .

In the actual repository 46 you have to add this line :

typedef unsigned long  ULONG;

to the header file: u3Base.hh after line number  211.

Then you are able to compile the sources with e.g. gcc version 4.7.2 under Ubuntu 12.10.

Beste regards,


The ULONG typedef was removed from the Exodriver header (labjackusb.h) a couple years ago and it looks like u3Base was expecting it from there, so it needs to be added to the u3Base source code like you are doing if using the current version of the Exodriver. Thank you for commenting on this and making others aware.

I tried getting the latest source code from this repository with the following command:

svn checkout http://svn.fiskeryd.com/svn/u3base/trunk/ 

Is there a default set of credentials or a particular command to get the latest source from the repository?

This class is user submitted and the subversion repository is maintained by them. If svn checkout commands are not working you will want to contact the maintainer whose information is in the README of the WebSVN repository (the link this page provides).

Also, the last subversion repository we knew of was at https://fiskeryd.com/svn/u3base which currently doesn't look available.


Is there any way to get in contact with Carl?  The SVN repo contents are completely unavailable.


In the repo's revision 43, I see the documentation's pdf file that is downloadable and has an email address:


cfriisha.myopenid.com's picture

Sorry for the mess with access to the repository.
Currently there is a number of server and system changes, so I have decided to put a compressed archive in the place of the actual SVN repository.
So going to the link, you will come to a page where u3base-2.00.0.tar.gz is available.
The class will be tested and corrected some time in January 2016.
Carl Friis-Hansen

LabJack Support's picture

Hi Carl,

Thanks for updating us and the page linked to. Let us know if you would like to update the link's URL or this page's text.