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Error 7 - TDMS open error

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Hi,

I am trying to develop a simple data logging using FPGA in compact rio system. I am just following the getting started tutorial in the net. The web address is below

http://www.ni.com/tutorial/11198/en/

 I am using Labview 2014, cRIO-9004 and chassis 9104.

I had compiled the FPGA project and built RT project as per the example. Now when I run the RT vi, I am getting an error "error code 7 - tdms open in RT.vi".

One more additional input is that, I am not able to configure read/write control to "count(uSec)" as per the example, it can be only configured to "overflow".

Could some one help me troubleshooting this error.

Regards,

Ignatius

 

 

 

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Hi Igni,

 

general recommendation: When you have problems with your specific VI you should attach this VI!

 

Now when I run the RT vi, I am getting an error "error code 7 - tdms open in RT.vi".

What file path are you trying to use? You know the file has to be stored on your cRIO target!?

 

One more additional input is that, I am not able to configure read/write control to "count(uSec)" as per the example, it can be only configured to "overflow".

What exactly are you talking about? Again: attach your VI!

Best regards,
GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO
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Hi Gerd,

 

Attached the vi for reference.

 

I was trying to use D-drive of the Host PC. How to configure the path to cRIO.

I may be asking you simple question but forgive me as I am new to the cRIO based labview program developing.

 

Regards,

Ignatius

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Hi Igni,

 

so my glass ball gave the correct answer: "Use a filepath available on your cRIO target!"

 

Your cRIO has NO ACCESS to the harddrive in your host PC! It's a computer on its own! (You wouldn't want your collegues to access your harddrive just because they access the same network!)

 

You need to store the data in the internal flash drive of the cRIO, usually found with the path "C:"…

 

One more additional input is that, I am not able to configure read/write control to "count(uSec)" as per the example, it can be only configured to "overflow".

You can only access existing FP elements of the FPGA VI! When there is no "count[µsec]" control in the FPGA VI your ReadWrite will not provide access to it…

Best regards,
GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO
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Gerd,

 

What about the read/write control in front of tdms open vi. In the example it was configured to count(uSec) but I am not able to do it. It has only "overflow" control.

After changing it to RT drive, the code is running fine but only for 2 sec and it throws overflow signal and stops.

Regards,

Ignatius

 

 

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Solution
Accepted by topic author Igni

Hi Igni,

 

What about the read/write control in front of tdms open vi. In the example it was configured to count(uSec) but I am not able to do it. It has only "overflow" control.

Again: when there is no "count(uSec)" control on your FPGA VI then you cannot select it in the ReadWrite node!

 

After changing it to RT drive, the code is running fine but only for 2 sec and it throws overflow signal and stops.

You need to read your FPGA FIFO in the RT host faster than the FPGA writes to it - otherwise you will run into an overflow!

- Remove the wait function in the loop.

- Use a producer/consumer scheme to separate DAQ loop and FileSaving into their own loops!

- Check the sampe rates in the FPGA VI. How fast are you writing into the FIFO?

Best regards,
GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO
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Hi Gerd,

 

Thank you very much for your kind help. Its working now.

 

Regards,

X. Ignatius

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Hi GerdW

I am facing a similar problem. I'm using a PXIe controller and on this target a Logging VI is running. The TDMS Advanced Open.vi is throwing an Error 7 code. I guess that I also need to store the data file on the PXIe target!?

How can I find the path to my target in order to set this path for storage?

 

thanx a lot.

 

sciu

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Hi again

 

I found the solution. Now I have to find out how I can reload the file in order to check the data..

 

cheers

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