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Convert Clock AI Strain Gage

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Hello, 

 

I am a newbie in Labview and would like to ask for help. I have a DAQ that has a maximum sampling rate of 102.4k samples per seconds. Since I am measuring a dynamic response using a strain gage, I need higher sampling rate. My plan is to use 8 channels and apply convert clock. I attached the VI that I am using as a reference downloaded from the NI website.

 

However, upon using this VI and changing it to Strain Gage (and setting up the gage configuration and specs), I am obtaining an error that the specified property is not supported (Error message: Specified property is not supported unless Sample Mode is set to Hardware Timed Single Point). Using a Hardware Timed mode significantly decreases the sampling rate. Any advice on how to move forward? 

 

I will appreciate any advice. Thanks! 

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Accepted by topic author steelguy

I kinda suspect this is going to be a constraint imposed by the type of DAQ device you're using.  What device is it?

 

Convert clocks are used on multiplexing devices, and most of the common ones I'm familiar with use SAR-style A/D converters.  Any time I've configured my own convert clock, it was for one of NI's multifunction boards that had a single SAR-style converter and used multiplexing to support multiple channels.

 

The strain measurement DAQ devices I've used have used Delta-Sigma style A/D converters.  I think they often feature simultaneous sampling across multiple channels, thus no need for (or support for) a convert clock.

 

 

-Kevin P

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Thanks, Kevin. I appreciate your response. I am using PXIe-1073 / PXIe 4331 / PXIe 4330. Upon checking the specs, my DAQ has Delta-Sigma ADC - simultaneous sampling. Thus, it appears that my sampling rate limit is 102.4k S/s. Any suggestions to increase the sampling rate using these devices would be appreciated. 

 

Worst case, my plan is to create my own Wheatstone bridge, purchase a PXI oscilloscope, then, measure the voltage across the bridge. Though I target to avoid buying anything at this point. 

 

Thanks so much! 

 

- JC  

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