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So a couple of years ago I was reading about the ZLIB documentation on compression and how it works. It was an interesting blog post going into how it works, and what compression algorithms like zip really do. This is using the LZ77 and Huffman Tables. It was very education and I thought it might be fun to try to write some of it in G. The deflate function in ZLIB is very well understood from an external code call and so the only real ever so slight place that it made sense in my head was to use it on LabVIEW RT. The wonderful OpenG Zip package has support for Linux RT in version 4.2.0b1 as posted here. For now this is the version I will be sticking with because of the RT support. Still I went on my little journey trying to make my own in pure LabVIEW to see what I could do. My first attempt failed immensely and I did not have the knowledge, to understand what was wrong, or how to debug it. As a test of AI progression I decided to dig up this old code and start asking AI about what I could do to improve my code, and to finally have it working properly. Well over the holiday break Google Gemini delivered. It was very helpful for the first 90% or so. It was great having a dialog with back and forth asking about edge cases, and how things are handled. It gave examples and knew what the next steps were. Admittedly it is a somewhat academic problem, and so maybe that's why the AI did so well. And I did still reference some of the other content online. The last 10% were a bit of a pain. The AI hallucinated several times giving wrong information, or analyzed my byte streams incorrectly. But this did help me understand it even more since I had to debug it. So attached is my first go at it in 2022 Q3. It requires some packages from VIPM.IO. Image Manipulation, for making some debug tree drawings which is actually disabled at the moment. And the new version of my Array package 3.1.3.23. So how is performance? Well I only have the deflate function, and it only is on the dynamic table, which only gets called if there is some amount of data around 1K and larger. I tested it with random stuff with lots of repetition and my 700k string took about 100ms to process while the OpenG method took about 2ms. Compression was similar but OpenG was about 5% smaller too. It was a lot of fun, I learned a lot, and will probably apply things I learned, but realistically I will stick with the OpenG for real work. If there are improvements to make, the largest time sink is in detecting the patterns. It is a 32k sliding window and I'm unsure of what techniques can be used to make it faster. ZLIB G Compression.zip

Phew that is a pretty strong opinion! Although I personally am not a fan of the overall style of DQMH none of my problems are with the scripting/wizards or placeholder text. I think any framework that tries to do "a lot" will be complicated... your own personal framework (which you likely find trivial to use) is likely to be a bit weird to others. DQMH is extremely popular for a reason... To paraphrase the words of a wiser person than I, "please don't yuck someone elses yum"

Seems like this one has "escaped everyone's grasp" too. ParallelLoop.ShowAllSchedules=True Because was only checked from the password-protected diagram of ParallelForLoopDialog.vi (LabVIEW 20xx\resource\dialog). Present since LabVIEW 2010. When activated, allows to apply more advanced iteration partitioning schedule. In other words, instead of this you will get this Сould this be useful? I can't say. Maybe in some very specific use-cases. In my quick tests I didn't manage to get increase in any productivity. It's easy to mess up with those options and make things worse, than by default. Also can be changed by this scripting counterpart.

Look at this new download on VIPM https://www.vipm.io/package/bjm_lib_request_power/

You want an ability to override the Equality or Comparison operators? I'm unsure, whether it really existed in OpenG packages, but now you have those neat malleable VIs, that let you do that: Search Unsorted 1D Array , Sort 1D Array , Search Sorted 1D Array. They have an additional input to specify your own equals or less function in a form of a custom comparison class or a VI refnum. There's an article to help: Creating a Custom Sorting Function in LabVIEW

This is exactly what was said in that ancient thread: Tree control in labview. So if you add 65536*N to the Item Symbols property of the Listbox and have the "Enable Indentation" option activated, you shift the symbol/glyph and the text N levels to the right. Could be useful for simple 'parent-child' relationships, if you don't want to use a Tree. And still it's used in Find Examples / NI Example Finder window:

I once went for an interview where they gave me a coding test and asked me to modify it. It was a very long time ago so I don't remember the exact modification they wanted (nothing to do with memory leaks) but I do remember the obtain queue and read queue inside a while loop with the release queue outside. I asked if they wanted me to also fix the memory leak as well as the modifications and they were a little puzzled until I explained what you have just said. I must have seen (and fixed) this while-loop bug-pattern a thousand times since then in various code bases. I also created this VI which I generally use instead of the primitives as it intialises on first call, can be called from anywhere, and prevents most foot-shooting by rolling them all into a single VI and ensuring all references but 1 are closed after use. Queue.vi

Those aren't typo's and errors. They are tests to see if we are paying attention.

In the past I have used the IMAQ drivers for getting the image, which on its own does not require any additional runtime license. It is one of those lesser known secrets that acquiring and saving the image is free, but any of the useful tools have a development, and deployment license associated with it. I've also had mild success with leveraging VLC. Here is the library I used in the past, and here is another one I haven't used but looks promising. With these you can have a live stream of a camera as long as VLC can talk to it, and then pretty easily save snapshots. EDIT: The NI software for getting images through IMAQ for free is called "NI Vision Common Resources". This LAVA thread is where I first learned about it.

Just to share how I got around this: By deleting 1 front panel item at a time I found that one single control was causing PaneRelief to crash; an XY graph. Setting it temporarily to not scale and replacing it with a standard XY graph (the one I had had some colours set to transparent etc) was enough to avoid having PaneRelief crash LabVIEW, but it would now just present a timeout error: I found a way arund this too though: the VI in question was member of a DQMH lvlib that probably added a lot of complexity for PaneRelief. With a copy saved as a non-member it worked: I could replace the graph, edit the splitters with PaneRelief without the timeout error (even setting the size to 0), then copy back the original graph replacing the temporary one, and finally move the copy back into the lvlib and swap it with the original. Voila! What a Relief... 😉 I probably have to repeat this whole ordeal if I ever need to readjust the splitters in that VI with PaneRelief though 😮

I confirm that this license is nearly identical to the standard EULA we use for our commercial products. Some wording is not applicable to a distributed palette of VIs like this. Our intention was to share a few reusable tools, used internally, with the community. Ideally, we should have released them under a standard open-source license such as MIT or a similar option. These VIs have been released “as-is,” without support or any guarantee that they will function for your specific use case. You may need to troubleshoot or fix any issues on your own. Feel free to use them in any context. I’ll look into whether it's possible to update the packages on the tool network to replace the current license with a more standard open-source one.

I put a temporary ban on inserting external links in posts (except from a safe list). We'll see what affect it has.

This is the modern 2020's equivalent of "works for me".

Your reporting of spam is helpful. And just like you are doing one report per user is enough since I ban the user and all their posts are deleted. If spam gets too frequent I notify Michael and he tweaks dials behind the scene to try to help. This might be by looking at and temporarily banning new accounts from IP blocks, countries, or banning key words in posts. He also will upgrade the forum's platform tools occasionally and it gets better at detecting and rejecting spam.

For fun. 😄 "Science isn't about why; it's about why not!" - Cave Johnson

Found it here @Ajayvignesh https://github.com/sandialabs/LVTM

Well I referred to the VI names really, the ZLIB Inflate calls the compress function, which then calls internally the inflate_init, inflate and inflate_end functions, and the ZLIB Deflate calls the decompress function wich calls accordingly deflate_init, deflate and deflate_end. The init, add, end functions are only useful if you want to process a single stream in junks. It's still only one stream but instead of entering the whole compressed or uncompressed stream as a whole, you initialize a compression or decompression reference, then add the input stream in smaller junks and get every time the according output stream. This is useful to process large streams in smaller chunks to save memory at the cost of some processing speed. A stream is simply a bunch of bytes. There is not inherent structure in it, you would have to add that yourself by partitioning the junks accordingly yourself.

With ZLib you just deflateInit, then call deflate over and over feeding in chunks and then call deflateEnd when you are finished. The size of the chunks you feed in is pretty much up to you. There is also a compress function (and the decompress) that does it all in one-shot that you could feed each frame to. If by fixed/dynamic you are referring to the Huffman table then there are certain "strategies" you can use (DEFAULT_STRATEGY, FILTERED, HUFFMAN_ONLY, RLE, FIXED). The FIXED uses a uses a predefined Huffman code table.

There is an example shipped with LabVIEW called "Image Compression with DCT". If one added the colour-space conversion, quantization and changed the order of encoding (entropy encoding) and Huffman RLE you'd have a JPG [En/De]coder. That'd work on all platforms Not volunteering; just saying

You could also check https://github.com/ISISSynchGroup/mjpeg-reader which provides a .Net solution (not tried). So, who volunteers for something working on linux?

From what I can remember, for LV 5.0.x and older RTE (i.e., a loader plus small subset of resources) was included into the EXE automatically during the build process. For LV 5.1.x there was a choice: to include RTE into the build or to use an external RTE. And since LV 6.0 only an external RTE was supposed. I could say more, such a trick is still possible for all modern versions on all three platforms (Win, Mac, Linux). The latest version I tested it on, was LV 2018, but I'm pretty sure, the technique hasn't changed much. I can't remember, from which version NI started to use Visual Studio 2015, but since then each EXE requires The Universal CRT, that is contained in Microsoft Visual C++ 2015 Redistributable. One could install such a distro on a clean machine or copy all these files from the machine, where such a CRT is already installed. Now besides of those the application will also require this minimal subset of folders/files (true for LV 2018 64-bit): On Linux it goes much easier (true for LV 2014 64-bit): For LV 2018 64-bit with a "dark" RTE it also wants And for Mac OS you can embed RTE into the application with this script: Standalone LabVIEW-built Mac Application with Post-Build Action. Of course (and I'm sure everyone understands that), the technique described above, is applicable to very simple 'a la calculator' apps and not very to not at all for more or less complex projects. The more functions are called, the more dependencies you get. If something from MKL is used, you need lvanlys.dll and LV##0000_BLASLAPACK.dll, if VISA is used, you need visa32.dll, NiViAsrl.dll and maybe others, and so on and so forth.

@hwkim418 There are many ways you can go about this. Here's a few examples using JSONtext. (VI saved in LV 2019) object_deserialization.vi

You might have more success posting this on the Discord. Most of the conversations happen there these days.

Hello ladies and gentlemen! Prepare yourselves for a massive wall of text. Thank you in advance. First time poster, long time lurker. Over the last decade I have found answers to a myriad of Labview related questions I've had on these forums, and I'm hoping some of you can help me out with my current conundrum. I've a solo developer for a large labview based automation project. I have worked with other labview developers in the past, but we've always kept what we were working on very compartmentalized because nobody ever wanted to deal with LVMerge. At the time they all said Labview effectively had zero way to merge VIs. Since those old days (9 years ago) we've come a long way. Unfortunately like many engineers I am horrible about UI/UX design - I'm trying to fix basic functionality, I don't care that you can't find the button (at least I don't care right then). But because of how solid the software is getting we're finally in a good position to start dedicating time and effort into improving our UI flow and design. So in the run up to this, and knowing I had basically zero experience with LVMerge/Compare except that the previous developers considered it "impossible", I did a few tests. My goal was to continue some development in the block diagram of the main top level VI in my own git branch, while another developer worked on UX changes on a second git branch. Then when he was ready we'd merge everything back together. All of his changes were focused on the Front Panel - he never opened the block diagram once. He was moving things, resizing things, changing captions and boolean texts, but never labels, and then adding various decorations as he wanted for clarity and organization. My initial test merges worked flawlessly. I was surprised how easy my small merges worked. From there he tinkered away when he could over 4ish weeks on the UI and I kept my usual pace on the main top level working on various bugs. I tried to limit what I was doing in the top level - most of the block diagram changes I made were cosmetic. It needed some TLC. Anyway fast forward and now we're ready to merge everything back together and ... I can't. I cannot get it to work. I've tried so much stuff. At first the errors were almost always during the LVCompare phase, usually about an insane block diagram object on the "base" vi. I'm familiar with heap peak so after a crash I'd comb the error log as well as I could (wish that thing had some documentation) and then try to find the offending object and fix it. More often then not I wouldn't see an issue with the object at all, and lots of the advice online is "just delete and remake the object" but I hate that solution because it means I fundamentally don't understand the actual problem, and when I'm merging three different versions of a big VI that gets tough to do. I've been experimenting with the tools, and eventually turned off auto resolve. Okay cool that would get me through the compare stage and actually open LVMerge where I could select which versions of things I wanted. From here it became a game of cat and mouse where I go through changes one by one till I get a crash, investigate, fix, change something related to said crash, and then run it again. This has been time (and sanity) consuming. It never worked, and eventually I got stuck on a merge change that I couldn't even identify what it was changing between the three, but I know that no matter which I select it crashes. I've kept trying various things since then. Resizing the tab control positions to be exactly the same Deleting a few FP objects on the base and FP update versions that I had removed when making BP changes on my version Adding a few objects I created for the same reason Added all 3 versions of the VI to the main most up to date project, opening and running them all to make sure there are no serious insane objects that are breaking them. They all run. This is by no means an exhaustive list of everything I've tried, but its what comes to mind right now as the major tries. Currently the state I'm in is that when I run it with all 3 versions with all the changes from above made to them, I can't get through the Compare stage because it crashes with a insane object error about "undo.cpp" which makes zero sense to me. What is it undoing? I tried limiting the number of Undos in LV settings, that didnt help, I tried increasing the limit greatly, that also didn't work (maybe didn't increase enough? Trying that now). I'm really deep in the weeds on this one now, and I would love some fresh perspectives. What's probably going to happen is that I'm going to write it all off as a lesson, and we'll just have the UI dev make his changes again on my current most up to date version - but I would really love to figure out the compare and merge process, and best practices for using it. The documentation for these is abysmal. There's basically nothing. I could probably pay for NI's annual subscription and maybe get some direct help from them but I had it out pretty big with some NI sales guys a few years ago when they transitioned away from perpetual licenses to the subscription model, and I don't want to pay them on principle; but I will if needed. Ultimately even if we do the changes again, I'd still like some best practices on where we went wrong and how to avoid this in the future. We're growing fast, and I could see having another full time labview developer working with me in the future and would love to come away from this with as many answers as possible on how to work in a team on labview binary files. If you've made it this far all I can say is thank you. Now please send help. PS: some info I should of added we use Labview 2021. I don't think we're on SP1, I don't remember why not, and I am willing to try updating. also willing to pay the sub and just upgrade to 2025, but not without good reason like someone tells me all about how they solved so many issues with Compare/Merge in the last 4 years and its going to be so much better I'm attaching my most recent error log from the crash I had last night. Its a doozy, reporting a TON of objects on both the FP and BP as insane. lvlog2025-08-11-15-32-09.txt

Hi My advice for managing multiple versions of LabVIEW is always the same : >>> Install only one LabVIEW version per partition if you also need to install any driver, toolkit or module. Or need other software that integrates with LabVIEW in some way. No exceptions. I do have VMWare installed with Windows XP to be able to open ancient LabVIEW versions like 6.1 or read the old CHM help files, accepting the sluggish performance of the VM environment. I avoid using it for anything 'serious'. To manage the span between LabVIEW 2018 and 2024 I would divide the disk into two partitions and install two copies of Windows and then install LabVIEW. To manage multiple partitions and selecting which to boot from by default, I recommend installing EasyBCD. But you don't have to. Windows creates a simple multiboot menu itself. There are other options too. But they require some dedication going into the art of multiboot management. ¤ You can install Windows on an external USB3 connected disk, SSD or FlashDisk. Microsoft abandoned the concept in 2020. But a program called Rufus revived the concept and now there are many tools that gives this as an opportunity. Works splendidly even with Windows 11. ¤ Some laptops ( and desktops of course ) support easy change of the disk. Sometimes using a replaceable disk craddle instead of the DVD drive. Good luck

Redis is certainly high performance and suited to multiple, loose writers, readers and subscribers, with bindings for so many ecosystems. One of its several features, which I haven't perused, are Streams. I'd be curious too to know whether continuous cross-app data streaming could be efficiently implemented using them.

Yup. There is: MMAP (1.0.1).

Aren't DVR's just LabVIEW's take on pointers?

I cannot look at your file, but I suggest save the data to TDMS or any binary format of your choice. Once the file is saved, then you can convert it to text.

There is no typos and errors in your posts. Only pearls of wisdom and oracles of truth that we mortals can't understand yet...

Drat, and now my typos and errors are put in stone for eternity (well at least until LavaG is eventually shutdown when the last person on earth turns off the light) 😁

Had the same issue. Removing a VI from a lvlib, using Pane Relief to set splitter size and moving it back to the the lvlib worked for me to. Thanks!

In addition to the LV native method, there are options with .NET and command prompt: Get Recently Modified Files.

Done some simple testing. On a directory containing 838 files it took 60 ms.

I have experienced the same thing when my VI was the member of a large class. I removed the VI from the class, set the splitter positions, and then added it back to the class. :shrug:

Open the search function (Ctrl+F) and browse for the "NaN" constant. A dialog pops up telling you this palette item is not supported by the Find Dialog... You can search for the "NaN" string and it will find all the NaN constants (plus all the occurrences of the "NaN" string). You can search for all other constants (pi, machine epsilon, +/-Inf, etc.), but not for the NaN constant, which is just a numeric constant with NaN typed in it. You can search for ALL numeric constants, but not for a specific one, say "1". Of course, you can search for all "1" strings in your code, and the constant 1 will show up among the search results, but it will be hidden in a long list of irrelevant results. And try to search for a constant with units... You can't. What would be nice is to look for a constant irrespective of its unit, as for instance 60 s = 1 min. Did I encode that time constant as 60 s or 1 min? I need to search for 60 AND 1 to find out.

I can create it without problems in LabVIEW 2018 and 2020! So it is either that Scripting is not enabled in that LabVIEW installation or a bug in backsaving some of the scripting nodes to earlier LabVIEW versions. And I'm pretty sure that the Diagram property (called Block Diagram in the menu) is available since at least 2009 or thereabout. I can check this evening. My computer at work only has LabVIEW versions back to 2018 installed.

Since you asked, here are my findings: LV23 - can create the attached snippet (don't know if it works), and save it for LV14 (also attached). All the pulldown menues show relevant properties LV21 and LV 19 - open the saved for LV14, show a correct image, but the first property node lacks the "Block Diagram" entry in the pulldown; further properties have no menu ETA - and show the relevant pulldown menues when "Show VI scripting" is checked. LV14 - the first property node menu *has* a "Block Diagram" entry, but the further properties don't match LV23 W14.vi W23.vi

Top Level here almost certainly doesn't mean the diagram of the template VI. Instead LabVIEW distinguishes between a Top Level diagram which is basically the entire diagram window of a VI and sub diagrams such as each individual frame inside a case structure but also the diagram space inside a loop structure for instance. The tricky part may be that the diagram itself may indeed only exist once and remains the same even for clone VIs. The actual relevant part is the data space which is separate for each active clone (when you have shared clones) and unique for each clone (when you have pre-allocated clones).

Example of camera grab using the Pylon .net API. (Credits: GrokAI)

Put the acquire image and save to file in the event structure timeout case, but only write to file conditionally (i.e. if the user has clicked the button)

A bit sad to have to say this nowadays that most of the traffic on this forum is about leaked videos, money rituals and human sacrifices, but isn't this the part where someone starts to repost links to basic LabVIEW training resources on the NI site?

Indeed. It's not a full solution as it doesn't support multiple streams, audio or other encoding types. But if you want to get the audio then you need to add the decoding case (parse is the nomenclature used here) for the audio packets in the read payload case structure.

Started playing with XNodes a bit and noticed the same behaviour as well. Really upsetting. But there is the solution. Just send FailTransaction reply in a Cancel case in the OnDoubleClick ability of your XNode and that 'dirty dot' never appears! That's exactly what the Timed Loop XNode does internally. Looking at this description I get the impression that this reply was invented precisely to overcome that bug (was even given its own CAR #571353). Similar thread for cross-reference: LabVIEW Bug Report: Error Ring Edit + Cancel modifies the owning VI

I don't have good examples to share, but here are a few helpful links for you: NI has an article dedicated to DVRs, which also explains the fundamental idea: http://www.ni.com/product-documentation/9386/en/ Here is a short video that explains how to use a DVR and some of the pitfalls: https://www.youtube.com/watch?v=VIWzjnkqz1Q Of course, you'll find lots of topics related to DVRs on this forum.

Here is a quick and dirty edit. It allows for column separators to be moved, but I noticed that on resize it will set the column widths. So this means if you manually move the columns, and then resize the control it may change the columns in an unexpected way. But at that point you can manually move the separators again. I only have 2017 and 2018 so this is for 2017 and newer now. Variant_Probe-2.4.3-0.ogp

Which is funny because when I took them, I thought the CLD was much harder than the CLA.

Maybe you'll get Xmas before you know it... I found a way to retrieve all tags from a VI. I basically scan the VI file and get an index to the position of tags in the file. I then extract the tag names. Since I don't know to which objects it is related, I have to scan all objects on FP and BD to associate them properly. Once done, you get a list of refnums and variants for the Object's references and a list of tags to which it is associated. I also included an example of code to write a tag to the Block Diagram. Use the same template to write to FP or any objects. Open the project and launch "Get All Tags from VI". Browse the path to the example file "Tagged Test VI" and that's it. Saved in 8.6 but will work in 9.0 (2009) as well. Note that the versioning is important as tags are seen only through scripting and NI can change the way it is saved from one version to the other. Retrieve Tags 8.6.zip