« Close

Datasheets and User Guides

App Notes

Software & Driver


What kind of things can be done with a LabJack?

Read the output of sensors which measure voltage, current, power, temperature, humidity, wind speed, force, pressure, strain, acceleration, RPM, light intensity, sound intensity, gas concentration, position, and many more. A LabJack brings this data into a PC where it can be stored and processed as desired.

Control things like motors, lights, solenoids, relays, valves, and more.




What is the smallest Hz LabJack can detect ? I am interested in .5-30 Hz range.

Here is a good forum topic about frequency measurement:


You are probably going to want the U3 or U6, and you will probably use a timer in 32-bit period measurement mode.  There is really no minimum Hz limit.  If the signal was too slow, you could always switch to software timing to go as long as you want.  The 32-bit period measurement mode will certainly work for your 0.5 - 30 Hz range.


Is anyone using this interface to conduct measurements with a class microphone using a interface similar to SpectraPlus DT?

I searched around and did not find any other mention of SpectraPlus software.  If the software has an open API that lets you call functions from a Windows DLL then you should be able to talk to a LabJack yourself, otherwise PHS would have to add the support.

any plans to port python 2x modules to python 3x anytime soon? 

There are no plans to port LabJackPython to Python 3.x.  We are currently developing a multi-platform Modbus driver, and have not decided what Python versions we will support in that interface.

Hello, Sorry for the amature question.. I am building a small system that would read analog signal from two potentiometers (1-5 v- can be changed..), compare the difference between them and as a result provide current to power a motor (6v). I need 15 individual systems such as that controlled in parallel. I don't need high speed acquisition, 20 hz are fine. Are your controllers good for my project. If so, please recommend the right one. Thanks, Ofer

Reading a couple pots is pretty straightforward.  A U3-HV is probably what you should look at.  As for controlling the motor, unless the motor is very small you need something between the U3 and the motor.  Perhaps you use a PWM output timer on the U3 to control the duty cycle of some sort of switch (transister, SSR, etc.), or perhaps you use an analog output on the U3 to control a motor controller or motor driver.  Try searching at labjack.comhttp://labjack.com/search using the term "motor control", and beyond that to get into more detail I suggest posting on our forum.



im new using labjack, i have have labjack u12, and i have to do a project, that is turn on and off a three-phase motor, and take current and voltage samples. I hope someone can help me.


thanks a lot.

That is not a trivial task.  I suggest you start by reading some forum topics:





Then you want to work on what you are going to use to turn the motor on/off (3-phase relay or some sort of motor controller?) and selecting voltage and current sensors.  To get into more detail, post on the forums.


I m new to labjack and I have to write protocols for using light meter,labjack U6 for controlling light intensity etc on pc for display on a screen.

Anyone please help me how to proceed


So the U6 will measure the signal from some light sensor, and then your software will perhaps use Windows API calls to adjust the brightness of the monitor?  The latter is not related to LabJack.  For the former, start a forum topic with a link to details about your light sensor.

This sounds interesting... but can you explain this with specific example?

Our blog has some various examples of projects we have worked on that might give you a few ideas.


please can read time values from the labjack u12.

i am reading level from the labjack and need to record the instantaneous times of each height.

Any clues and suggestions will be appreciated.


How fast are you sampling the readings?  What are you using for software?  Typically you use software to provide timestamps.  I suggest you continue this discussion on the LabJack forums.

I have LabJack U3 LV in my lab

i need to analyze sound absorption coefficient and i used 4 microphone as sensor

can i use labjack to measure it?

The things to consider are whether the signals can be measured by the U3 and how fast they need to be acquired.  I suggest using the forum to go in to more detail.

What sort of signal do you get from the sensors?  Voltage signal?  Max and min voltage?

The max sampling rate of the U3 is 50 ksamples/second.  That means you can scan 4 channels at 12.5 kscans/second.  At that scan rate you acquire frequencies up to 6.25 kHz, but anything higher than that will alias and appear as a lower frequency.


I have Labjack U3 ,U12 and LABVIEW 8.6v .

How can I interface both these Labview and labjack to run a stepper motor as per the Labview results.

I also downloaded all the necessary files and added to my labview add-on list, but I still don't find any way to do my own functions.

I am using only the example programs . How can I solve this issue. Pls help me out.

Thanks in advance.

I would first recommend that you get started by opening our LabVIEW example programs to see how each of our provided VI blocks is used.  We have many provided VI's that let you open, configure, and control our devices.  Once you install the driver you should be able to open the VI's and they should run. Just in case you are having trouble finding our LabVIEW page:


Once you have become comfortable with our device I would recommend using the google custom search bar on our site to look for more specifics on controlling servo motors with our devices.  We have many forum posts regarding stepper motor use with our devices:



Can Labjack controll halogen lamp (12 Volt) via electronic transformer (TE-0105 U 1-10 V sc) from tridonic?

It looks like the TE-0105 is a dimmer for low-voltage halogen lights.  Sounds like you want to control the dimmer by computer, so are wondering if the LabJack an go between the computer and dimmer to provide the interface.

We need more details about how the dimmer is controlled.  In Tridonic's "Transformers Overview" document, I see quick mention that communication with the dimmer is "switchDIM, DSI, DALI, or 1-10V switches".  Does the TE-0105 support 1 of these or all of these?  We need more details about these communication options.

I found more information on these interfaces:  switchDIM, DSI, and DALI are all digital interfaces of sorts.  It might be possible to do switchDIM by using the LabJack to control a little SSR, but we would need more detail about switchDIM.  As for DSI and DALI, they use manchester encoded asynchronous communiction, and we do not support manchester encoding.

Wiki does have an entry for 0-10 V lighting control.  This is a simple 0-10 or 1-10 VDC analog signal that controls light from 0 to 100%.  That can be done by using an LJTick-DAC with a U3/U6/UE9/T7.  The only question is whether the "0-10 V lighting control" described on Wikipedia is the same as the "1-10V switches" mentioned by Tridonic?

Is it possible to us a labjack to output 0-10 volts using  LabVIEW?

The built-in DACs on the U12/U3/U6/UE9/T7 are ~0-5 volts.  To get 0-10 or +/-10 you can add an op-amp or use the LJTick-DAC.  See Section of the U3 User's Guide.


I currently have a labjack U3-HV and a CB15 with DAQ Factory software. I would like some help on how I could control up to four 24VDC solenoid valves for a test rig I am working on. Is this possible with this set up?

I will need to turn them on/off and control them to a required cycle sequence, alternating between the solenoids and at times having some of them on at the same time.

Any help would be appreciated to get me started and onto the right track please.



In terms of hardware, the U3 will control some sort of switch that is rated for 24 volts and the max current of you solenoid.  Among other options, that switch could be the LJTick-RelayDriver, PS12DC, RB12 with modules, or a stand-alone SSR.  Of course, you will need a 24 volt power supply also.  For further help I suggest you start a forum topic and provide more details about the solenoid.  Do your initial hardware testing using the test panel in LJControlPanel.

As for how to make DAQFactory do the sequence you want, I suggest you post on AzeoTech's forum.