Anyone ever use a Labjack with LabVIEW?

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Discussion Overview

The discussion revolves around the use of a Labjack device with LabVIEW, specifically focusing on issues related to voltage measurements and potential hardware problems. Participants are exploring the behavior of the device when measuring small voltages and the implications of impedance on the readings.

Discussion Character

  • Technical explanation, Debate/contested

Main Points Raised

  • One participant reports consistently measuring around 1.28V on the Labjack input, even when applying 0V, and seeks assistance in resolving this issue.
  • Another participant questions whether the device still shows 1.2V when grounded and inquires about the linearity of the scaling when a voltage is applied.
  • A participant confirms that when applying a 5V input, the Labjack reads 5V accurately, but the unexpected voltage appears only with smaller applied voltages.
  • One participant suggests that the issue may be related to high impedance in the signal, which could prevent proper driving of the Labjack's analog inputs.

Areas of Agreement / Disagreement

Participants express differing views on the cause of the measurement issue, with some suggesting hardware faults while others propose impedance-related explanations. No consensus is reached regarding the exact nature of the problem.

Contextual Notes

Participants have not fully explored the implications of impedance on the measurements, and there may be missing assumptions regarding the setup and configuration of the Labjack device.

G01
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If anyone has, then I sure can use some help. I'n trying to measure a voltaage with one of the inputs on the jack and I keep getting screwed up measurements since the Input always has some voltage on it no matter what. Even if I apply 0V to it, it will still measure around 1.28V. Does anyone here who has used this device have any idea how to fix this, or do I just have to nwork around it? Thanks a lot.

EDIT: I'm sorry, I went to GD out of habit and posted here! Could someone please move this to the correct forum? Thanks again!
 
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Even if you ground it its still showing 1.2v?

What about when you hook up a voltage, does it scale linearly? (5v input shows 6.2v)?

I have some labview experience, but if youre getting readings perhaps its faulty or leaky hardware.
 
Thats the weird thing. When I hook up a voltage of 5V, the thing reads 5V!

I only see this other voltage when the applied voltage is small. I really have no idea what's wrong, here.
 
Sounds like you are talking about the LabJack U12. Sounds like your signal has too much impedance and can't properly drive the U12 analog inputs. See the following from our forum:

http://www.labjack.com/forums/index.php?showtopic=889"
 
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