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What Block (function) is this?

I'm doing a project and came across a block function that I have not seen before and can't seem to find any information about. What is it? I have attached it. 

 

 

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Hello all, 

 

I have a Hampton VA HR 100 LVDT sensor. I want to measure the position of a rod within the LVDT sensor (displacement). I am new to Labview, but I managed to get a VI working. 

 

My first issue is that I cannot select the device as an LVDT Analog input, rather, it must be read as a Voltage input when I start up the DAQ assistant on the VI. That works, however, the movements of the rod seem to indicate an acceleration rather than a position change. I have attached the graph of the VI that I get for 10 samples at 100 Hz. I also attached the VI. I need to get it to read it as a position, hence the voltage reading should indicate a displacement, and not just go back down as soon as I stop moving the rod. 

 

 

I am using a NI USB-6009, with grounds connected to both the 5V pin digital side and the analog side. Any help is appreciated. 

 

Thanks. 

 

Alessandro Laspina. 

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Message 1 of 32
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That looks like a custom VI somebody wrote.  Is there anything in the context help?  What is inside of that VI?


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I was hoping that was not the case. This is the entire block diagram. I'm assuming it is a custom DAQ write or read VI. 

 

 

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@alaspina wrote:

I was hoping that was not the case. This is the entire block diagram. I'm assuming it is a custom DAQ write or read VI. 

 

 


Yes, there is a producer-consumer design with some bad programming practices (strange usage this as subVI, silly way to stop the parallel loops and lots of local variables, flat sequence structures, etc.) used in that VI. If you attach the actual VI instead of a useless png screenshot, we could have a better look at it. 

The question is that, what is your goal? Did you inherit this project from someone? What do you need to program? Based on your initial question, you are a beginner in LabVIEW. Did you go through the online training or some course yet? 

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is there anything wrong in your program?

what are you want to do with this vi.

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@alaspina wrote:

I was hoping that was not the case. This is the entire block diagram. I'm assuming it is a custom DAQ write or read VI. 

 


This seems to be the block diagram of the toplevel program. I wonder if you could show us the block diagram of the subVI in question. What's the file name of the subVI? What kind of DAQ hardware are you using?

 


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What would be the sub VI?

 

LVDT reading with a HR 100 LVDT sensor. It is not working, and it is most likely because of my current VI block diagram. Problem is I cannot follow the steps that the previous person did to make it work.

 

Any resources for creating a VI that reads position from an LVDT sensor? 

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I'm not quite sure about your sensor. But I do know this, if you have acceleration you can integrate it to get speed and from speed you can integrate it to get position. You can find the integration VI under: right click in you block diagram >> Mathematics >> Integration and differentiation.

 

It can also be done manually like in the attached file, but it's not at the same quality as the NI stuff would be.

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@alaspina wrote:

What would be the sub VI?

 

LVDT reading with a HR 100 LVDT sensor. It is not working, and it is most likely because of my current VI block diagram. Problem is I cannot follow the steps that the previous person did to make it work.

 

Any resources for creating a VI that reads position from an LVDT sensor? 


It'd be the VI you asked/posted about first.

/Y

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