Noise Reduction for USB 6002

[KurtzC1]

Hello Everyone,

I am trying to gather pressure data from a MEAS pressure transducer. I am using Labview 2014 with a NI USB 6002 board using channel A0. I am able to successfully read and write data to a text file; however, there is a lot of noise. How do you reduce this noise?

I am new to Labview so I don’t know methods of processing live data. I tried post processing the data but to no avail.  Down below are images, my hardware, and a copy of my code. 

Any Information Would Be Appreciated!

Pressure Transducer Model: MSP-300-100-P-2-N-1

NI Board: USB-6002 P/N 154424C-02L

http://imgur.com/a/xDuTR

[cbutcher]

A few comments on your measurement, then a couple on your code:

• The imgur post shows you sampling at 50kHz. The datasheet that I found for the MSP-300 suggests it might have a typical bandwidth of DC->1kHz. You might want to sample more slowly.
• It's not obvious from the number you gave compared with the ordering details on that datasheet exactly what sensor you have, but it seems likely there is a 1% FS error on the sensor. If the output is 10mV/V, you should have a Full Scale range of 50mV, and so the oscillations you're seeing are pretty large (~+-5mV?), but if your sensor has a larger full scale range, this error is correspondingly smaller. It might be (depending on your sensor) that you're approaching the lower limit of your measurement accuracy.
• Please leave labels visible on both the block diagram and the front panel. Captions can be used instead on the front panel if you want to use something like 'HiV' for the label and 'High Voltage' for the front panel to save space, but don't just remove all of the labels. It makes it very challenging to try and work out what is connected to what. Labels can also be dragged away from their controls on the front panel (and BD) so that you could reproduce your current design if you wanted.
• You label some of the buttons 'Start ...' but actually they toggle it on or off. Try to use labels which describe the actual action, rather than something similar but different. An example might be 'Record' rather than 'Start Recording'.
• In your uploaded VI, the filter isn't being used. Probably you know that and it was just the remnants of an earlier test?

[KurtzC1]

Hey cbutcher,

It turns out my USB-6002 was not grounded properly. Once grounded the noise disappeared.

However, I am still having issues with my VI. When I write to a text file, Labview outputs error 200279. An image can be seen at the link below. I tried increasing the buffer size, number of fixed samples, and sample rate but nothing worked.

Acquisition Mode of DAQ Assist is currently at “continuous samples.” If I change Acquisition Mode to “N number of samples” less than 10samples/sec are written and sometimes it crashes.  I would like at least 50 samples/sec.

Any Information Would Be Appreciated!

Pressure Transducer Model: MSP-300-100-P-2-N-1

NI Board: USB-6002 P/N 154424C-02L

http://imgur.com/a/8ToSH

[Anthony.M]

Hello,

I would advise starting a new thread for assistance with this error.

The following articles cover sample speeds and buffers extensively and are a great place to start,

Why Do I Get Error -200279 from my DAQmx Read VI or Property Node?

From <http://digital.ni.com/public.nsf/allkb/AB7D4CA85967804586257380006F0E62>

How Is the DAQmx Buffer Size Allocated for a Finite or Continuous Acquisition?

From <http://digital.ni.com/public.nsf/allkb/E1E67695E76BA75B86256DB1004E9B07>