infinitenothing

That part that's still confusing is that it looks like you have just one independent variable (time). If that's the case, that's just 1D interpolation. Also, your time vs x and your time vs C look like it has one slope so potentially, that's even more simple in that it's just a simple Y=m*X+b calculation. Also, it's not clear how much of this is calculable offline (no real time required).  Also, your original example used extrapolation and it's not clear if that's a requirement.

No, that probably doesn't work how you expect for negative numbers. Fortunately, for fixed point numbers, the decimals are just the least significant bits. The cool thing about that approach is that the code is just a wiring operation and thus uses ~0 resources and 0 time to calculate.

Can you post your example? 300-400 points per second should be no problem at all and quite fast

I believe what you described is extrapolation and I think you've under defined your system (or you actually want 1d interpolation). What would points (1,2 and 2,1) correspond to? It's not totally clear how you would want to determine that 0.5,0.5 corresponds to 0.5. A naive approach would be to use the slopes of 1,1 to 1,2 and from 1,1 to 2,1.

I don't quite recognize that node. It looks a bit like a delay node.

Regarding the transfer function, you can always use something like the central difference to approximate the derivative and simpson's rule to approximate an integral. Once you have those, you can take the derivative of the derivative to get the higher order derivatives and so forth.  Here's an example using slightly simpler approximations:

You have the right idea. You can add the DLL to your exe build spec instead of your installer though.

I don't think you're going to find an easy way to transfer this automagically to FPGA. You're going to have to break it down into developing your own nth order derivative and integral functions. Are you using compact RIO? If you don't need a crazy fast loop rate, you should be able to simulate your FPGA code as HIL running in RT which would make the development a little faster.

I stopped using variant attributes when maps and collections were introduced.

I see no downside to learning a new language on the side. Even if you never use it professionally, it's still fun to learn new things and it will certainly help you think in different ways. My suggestion is to use the languages that keep you close to hardware:

C++ with Arduinos. This lets you connect to other chips that will give you your ADCs, DACs, GPIO, etc.

Python with the Raspberry Pis and other single board computers

The LINX toolkit lets you get your feet wet with the above hardware in LabVIEW. You can go back and forth and see how each tool handles the same task.

Verilog so you can get back to graphical programming with the IP integrator. This will also get you high speed ADCs and DACs if you need that performance.

In other good news, you're now forced into a clear line between the UI and the backend. I suggest Javascript/HTML for the UI.

Most people compile their code into an EXE for distribution. But, yes, plan B would be to send the top level VI and all the dependencies. One way to do that is to use the "save as previous" feature which will automatically pick up most of the dependencies. https://www.ni.com/docs/en-US/bundle/labview/page/saving-for-a-previous-version.html

Can you give us an example of how you want to convert? For example if you had 1 byte: "A", you could convert that to 10 (a number), you could convert that to "10" (a string), or you could even convert that to 65 (the numeric value of the "A" character)

Hex display shows each character of your string as two alpha numeric values. For example, if I wanted to show "My string" as hex it would show "4d7920737472696e67" where 4d was the M, 79 was the y. It's useful for undisplayable characters and things like that

Could you make an array of hex strings and then use index array with an enum wired to the index to select the right program? Then you use an event structure to execute that when someone presses "send" button

How much data do you need from your sensor? My usual go-to for the raspberry pi is to run a webserver, build that as a startup VI and then the server will run any time the Pi is on. You can use LabVIEW's HTTP Get function from Untilted 4 to get your data. This might not work so well if you need a lot of data. I'd probably use the STM library instead of a webserver in that case.

Alternatively, have you tried the split string function?

https://www.ni.com/docs/en-US/bundle/labview/page/glang/search_split_string.html

Or, you could try a monospaced font and tape on the screen.

I'm curious why you went with the 6556. I probably would have gone with a LINX solution. Anyhow, I did a little searching and it looks like there's a SPI library/examples for that card.

https://forums.ni.com/t5/Digital-I-O/SPI-Communication-using-PXIe-6556/td-p/3591472

Protocol buffers is one part and I think a cross platform scripted method of defining a typedef is cool.

I definitely got lost a couple times figuring out what was "my code" and what was the toolkit and I had to reinstall the toolkit at least once.

I think if I were making the tool, for a unary server, I would have used VI references similar to "nonlinear curve fit" uses them instead of an event structure. The event structure comes with too much baggage and doesn't enforce a response.

I still don't fully understand how to manage a streamed response. Shouldn't the read timeout be set at each place the data is read instead of a global? Seems like it lends itself better to a queue or something.

I feel like REDIS accomplishes most of the goals that shared variables attempt to cover (minus some UI sugar) in a nice cross platform way. Does anyone have an opinion on "in memory" key-value stores that are accessible over a network?

5 hours ago, ShaunR said:

If Emerson buy NI, you can look forward to no LabVIEW at all.

At least we'd know where we stood rather than being strung along in uncertainty.

I found a related thread that might be helpful

It would be nice to be able to do more with the call library node without having to wrapper everything. If anyone wants to post something on the idea exchange forums, I'd likely give it a vote

Yes, I'm in. Thank you

That link is still invalid for me

I've never used the openg zip library but most of the packages I've used are static linked and just get uploaded/compiled as needed.

FYI, the 9627 doesn't have enough disk space with the system image to use the RAD/system imaging tools so you won't be able to replicate it. I'm stuck with 2019 until all our 9627 targets are out of support.

On 11/10/2022 at 11:26 AM, Lipko said:

Yup, I mentioned the reference thing too. With reference array you of course have to do explicit array indexing and wire the reference all around, I don't see much improvment. It's just personal preference 

The advantage is that indexing an array of refnums does not change the internal semi-hidden active plot state of the control.

2 hours ago, Lipko said:

I don't see how should Labview know which plot you intend to work on and what different method there could be. Sure, the above example should be easy to figure out but it's easy to come up with funkier situations. Maybe each plot should have its own reference, but I don't see that a superior solution. Or maybe choosing the active plot should be forced (invoke node instead of property node)? That's not too sympathetic either.

This pattern is far better than having an array of sub-property clusters and to manipulate those arrays. Though I agree that all these types of properties should have array version too, like graph cursors and annotations for example.

I often do ugly hacks with graphs and this problem never really got me. The code in the original post (I don't understand as it has some new blocks I don't know) seems like the model-view-controller is not separated enough.

I think either of those ideas would be superior. The graph should have a plots property that returns an array of plot references. We see this architecture with things like tabs having an array of page references. An invoke node that didn't force you to do a write when you only want to do a read would also avoid this problem.

38 minutes ago, drjdpowell said:

Does a Property Node, with multiple Properties set, execute as a single action, without a parallel Property Node executing in the middle?   If so, then resetting the Active Plot in the second Property Node in the bottom loop would prevent any race condition.

Even if it was a single action, is there a promise to maintain that in future versions? I solved this issue by wrapping the graph reference in a DVR.