simple pressure transducer

[tacky]

Hi

   Does anyone have a simple pressure transducer vi with offset null built into code. I am fairly new to labview and most examples I have seen are way to complex for me to figure out what is going on.  Is it better to use DAQmx or DAQ assistant?  I have two pressure transducer (omegadyne-10V excitation) hooked up to a SCXI-1327 TB with a 1121 module. I wrote a program to convert mV to pressure using linear scale but that's all I know how to do at this point! And I want to know how to read both tranducers.  Thanks!

[ManLongAtNI]

Hello tacky,

The DAQ Assistant is built off of the DAQmx driver and is typically a good tool for basic tasks but can fall short when doing advanced configurations. In your particular case, you will need to use the individual DAQmx VIs to perform your task. I was able to find the the following Example, Load Cell Data Acquisition with Null Offset and Shunt Calibration, searching the online community. Keep in mind you will need to make some modifications to make the example applicable for you. You will need to change the scaling appropriately, excitation and shunt calibration.  

Hope this helps.

[ManLongAtNI · Accepted solution]

Keep in mind that you will need to change your excitation from internal to external and remove the portion with the shunt calibration.

[tacky]

Thank you for the vi.  I have one question about switching to external as you suggested.   I am still using the 10V excitation provided by the 1121 module and chassis so will it be internal?  I though that external means any other source outside the chassis system.  Does the DAQmx provide the excitation? 

[ManLongAtNI]

Hello tacky,

I referenced the wrong module, but with the 1121 you can provide excitation. You can select internal excitation and by setting this the driver communicates to the hardware to provide the excitation.

[elambdin]

 I am wanting to use the load cell in unison with a load frame apparatus.  I want to apply a sequence of loads with a hydraulic motor.  Staring from 50lbs-300lbs in increments of 50lbs.  I want the user to first input 50lbs.  When the load cell registers 50lbs I want the vi to stop and the testing to stop.  From here I will take measurements, reset the experiment to zero and start the test again with a 100lb desired load.  To stop the hydraulic motor I have a relay which I want to open when the load reaches the users desired input of 50-300lbs.  To open the relay I stop the 5V signal in the attached vi.  Any help is greatly appreciated, as I am extremely new to LabVIEW.  

***Disregard the load cell and pressure transducer in the top left of my block diagram.  This was how I originally tried to accomplish my above question.  I was informed that I want to avoid using the DAQassistant for this task.  The 5V code using the DAQmx works and has been tested.  I just want to incorporate the code for the load cell now.  Once this is complete I hope to study it and understand it enough to replicate it for the pressure transducer we have as well.