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LabVIEW FPGA Advanced Session Resources Feedback

Please use this forum to dicuss feedback for the LabVIEW FPGA Advanced Session Resources

Thank you

Stephen B
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Message 1 of 66
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Hi Stephen,

I use the FPGA Advanced Interface Tools in quite a few projects so I was very keen to see what would be replacing it - while I'm pleased that you've converted it to a VI Package for ease of installation/updates - there are a couple of things I'm not too sure about with this new library.

1) Does this overcome the limitations of the original tool in not being able to read/write other data types such as fixed point numbers / SGL and, as you've done in the example, clusters?

2) You have the Data Type FPGA reference control you wire into the Get Single Resource Session - do I have to create one of these controls/typedefs for every single data type I need to read/write from the FPGA? It is a real pain to use the 'Configure FPGA VI Reference Interface' dialogue - if I have an FPGA VI with lots of controls/indicators and I accidentally delete the right one, I have to go back and import the whole lot from the bitfile again!

(I did have another question but it was answered by the nirviGetControlsFromBitfile.vi comment in the article)

Thanks,

Sam

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Hi Sam,

Great questions.

1) Yes, since it uses the native LabVIEW FPGA interface sessions

2) Yes. Each child session you create needs to be typed. So you will have to specify the data type. To ease this, you could create master refnum(s) of your entire bitfile(s) somewhere and then whenever you need to get access to a specfic item, just copy this refnum constant and delete out what you dont want then rename it to Value or FIFO.

Hope this helps!

Stephen B
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The VI package download has been removed as we prepare a formal National Instruments installer which should be posted next week. Before running that installer, you will first need to uninstall the VI package if previously installed. Thank you for your patience.

Stephen B
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Posted it    

Stephen B
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Hi, Just some feedback. The installer does not install any documentation with the VI (no help from floating help window). Resource Name In connector is not required, and it does not like any terminals with name of "Value" inside a cluster, but I guess the last one is a limitation as we already have to rename terminals to Value. Would be nice if that limitationen was written somewhere.Thanks for the "toolkit", it really helps me out alot.

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Hi JHE,

I'm glad it is helpful! Thank you for the feedback, I was not aware of two of those issues. I've documented all 3 now on the known issues list.

Stephen B
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I am glad to help. Is there anything that can be done about the performance? Reading a simple integer property takes about 20 ms. This is on a cRIO 9068.

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Hi JHE,

The performance of the read or write node should be identical to regular LabVIEW FPGA interface. In my testing I was able to read dozens of cluster indicators in ~100 microseconds.

Are you only measuring the performance of the read/write node or are you also including opening and closing the reference? Those calls should be done outside your loop.

Take care

Stephen B
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Hi,

I was opening the reference on each call, reading the property and closing the reference again because I was getting warnings.

After caching the reference, the performance was much better. It is still ~30 microseconds slower for each readout, but that is not a problem.

How do you manage to read a dozen properties so fast? I read 4 properties in about 300 microseconds running in a timed loop on a 9068 Compact RIO. The RIO is not doing anything else.

Thanks,

Jens


PS: What is the future development plan for this tool? Integration with LV FPGA?

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