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Veristand frequency

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Hello, 

I use a compactRIO with a voltage input module. I have to measure speed with an hall sensor until 10 kHz (square signal). I connect the module with the scan engine Ethercat. I have directly put bloc in veristand to do a counter, however the module gives information only each 0.01 s. So it's too slow for my operation. The counter works in 10 kHz. So if somone knows where I can change the speed information given by the module?

The module is an NI 9205 and it can reach 250 kHz (in the datasheet).

Thank you for your help.

 

Leo

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Hi Leo,

 

I ran into something similar with a DI counter.  It seems that VeriStand will only poll the I/O card at the RT loop rate (i.e 1000hz).  I had to write a custom FPGA code to run my counter at a faster rate then report it up to the VS engine independent of the Scan engine addon I was using.  You can do this while still using the Scan Engine addon if needed (this is what I did).  I think newer versions of VeriStand let you use waveforms, and this might work for you (have the card count, then send up the data every RT loop cycle).  Hope that helps.

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Thank you for your quick answer. So to write a fpga code I have to use Labview or Matlab and after export to Veristand? Maybe do you have a link that can explain to me? Thank you.

 

Leo

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Solution
Accepted by Grusta07

You will need to have FPGA as part of labview to do this.  If you haven't done FPGA programming there will be a learning curve.  Here is a link

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000YGlLCAW&l=en-US

 

I am assuming you are using the EtherCAT Scan engine addon.  

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Before you go down the FPGA route.  Look at Chassis->DAQ->Waveform Tasks in your System Explorer.

 

This looks like it will allow your to sample at your 10K.  You will have to read up on this since I have never used it.

 

 

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Thank you for this very good link.

Just one question, I saw that veristand 2021 works 64 bits. To use labview with the compactRIO I have to take the 32 bits 2021. But I saw somewhere that veristand works only with labview 64 bits (to convert model to veristand). For this operation it's working to have labview 32 bits?

 

 

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What I read is that you have to develop and build your FPGA in 32-bit LabVIEW and once you have your bit file, you can use that with VeriStand since the bit file itself doesn't run in VeriStand (it runs on the FPGA itself).

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Hi,

 

I am using Veristand 2017 with cRIO 9049. I am acquiring a counter signal with NI 9361 counter card.

My data acquisition rate is now 2KHz(2000 samples per second).Now I wanted to change to 5KHz.

As you said send high-speed data to veristand engine. Please explain how can I do that.

Also could you please elaborate on the waveform option?

 

Thanks in advance.

 

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Are you using the VeriStand Scan Engine or a custom FPGA for VeriStand?  If you are using the scan engine you are at the limit of it speed.  You would have to use a custom FPGA for that module or move all the IO into a FPGA project.   To do data acquisition you need to have your Target rate at least at 5K.  Your target rate is under Targets->Controller in your system def explorer.  

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Hi Joshe,

 

Thanks for the response.

 

I have tried to change the data acquisition rate 5KHz though Targets->Controller in your system def explorer. But it couldn't go beyond 2KHz.

I am using FPGA project. I have taken the refence of sample veristand-FPGA project.I am reading FPGA IO's in FPGA project and sending them to DMA.

NI_FPGA.png

 Here is the image.

 

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