LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Trying to Setup a Load Cell

I'm trying to setup a Load Cell in Labview an having some trouble. I'm a complete beginner in Labview.

 

So, I set it up with DAQ Assistant with a Bridge setup (Voltage with Excitation). I originally set it up as a Force setup but when I got incorrect outputs I decided to switch to Voltage and do the math myself. 

 

The equation I use to convert Voltage to Load is:

 

Load =  Vo/Vex * (Full Scale Capacity/Sensitivity)

 

When I put my load cell in my calibrated load frame I'm off by a factor of 10 (for ex. I read 4 kips instead of 40). 

 

The sensitivity of the LC is 2.2649 mV/V. 

 

I can't figure out what I'm doing wrong, any help would be appreciated. My block diagram and DAQ Assistant windows screenshots are attached. Voltage Bridge.PNG

 

Block Diagram.PNG

Hardware/Software

PXIe-1078 chassis

PXIe-4330Module

TB-4330 terminal block

Labview 2019

 

0 Kudos
Message 1 of 6
(2,131 Views)

What hardware are you using to read in the signal from the load cell?

0 Kudos
Message 2 of 6
(2,119 Views)

Ah, sorry forgot to mention it - I addded to the original post.

 

PXIe-1078 Chassis with embedded controller

PXIe-4330 module

TB-4330 terminal block

0 Kudos
Message 3 of 6
(2,109 Views)

If I understand the documentation correctly, you are off by a factor of 10 as the card reads in ratiometric and not absolute meaning the base units will be in V/V not in Volts. Youwould need to multiply by the excitation voltage to get the correct value. 

0 Kudos
Message 4 of 6
(2,018 Views)

Ahh, thanks! For me the manual was a little clear but that does make sense.

0 Kudos
Message 5 of 6
(1,984 Views)

 could you share your code for this if you still have it?

0 Kudos
Message 6 of 6
(861 Views)