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Datalogging buffer that only writes to USB on c-RIO

Looking for something specific here. I have access to some Linux based c-RIOs. I'm looking to implement a simple database on the controller and save it. I've settled on SQLite for the database, however I'm going to be saving several data points over a long time. To mitigate this, I want to extend the memory of the c-RIO with an USB hard drive/ Stick, but even that is finite storage. So I want to be able to remove the USB and remove the data from the USB stick and reinsert. I was thinking of a buffer for the data that can last long enough to transfer data and be reinserted into the c-RIO.

 

I've been looking at this to accomplish the removal of the USB drive from the c-RIO, but unsure how to implement the Buffer part.

https://forums.ni.com/t5/Example-Programs/Check-If-A-USB-Stick-Is-Present-On-Your-CompactRIO-Control...

 

 

Any Suggestions?

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Hello,

 

Can you let me know which cRIOs you are considering using for this?

 

Since all of this seems possible, the limiting factors are primarily going to be the onboard memory of the cRIO, the size of the datapoints you're logging, and how many of them you're logging per time period.  We can narrow down our best options from the cRIO with the most onboard storage.

Tyler O.
Applications Engineer
National Instruments
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@tobriant wrote:

Hello,

 

Can you let me know which cRIOs you are considering using for this?

 

Since all of this seems possible, the limiting factors are primarily going to be the onboard memory of the cRIO, the size of the datapoints you're logging, and how many of them you're logging per time period.  We can narrow down our best options from the cRIO with the most onboard storage.


Either the 9038 or the 9042, both Linux machines. I will be doing some large scale control and data acquisition. I am looking at 300+ data points being read every second. Per the project specs, I want to extend the onboard memory with and external hard drive, but I want the ability to notice when the drive is removed and save data points for... say 30 minutes while we save data elsewhere and plug the drive back into the c-RIO. Then the saving can continue on the drive with the buffered data from when drive was removed saved first. Like a FIFO but more robust

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So if we take the low bar of that:

 

300 data points / second * 60 seconds / minute * 30 minutes = 540,000 data points.

 

Do you know how much space one set of these 300 data points would take up?

 

Tyler O.
Applications Engineer
National Instruments
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