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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

We're back again this year. Free 24 hours of virtual LabVIEW presentations. Come join us! https://www.glasummit.org/ We're also looking for presenters. I know some of you all have a lot of opinions...

Are you seriously expecting anyone to install a random executable on their system from an unknown publisher, provided by an anonymous person on the web, where one can't even get a proper link in Google to the actual company page? Sorry, but anyone doing that should not be allowed near 5m of a computer system!

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"

Hi there ! If this subject interest you, I'm currently working on a new State Machine Toolkit for LabVIEW. You can find some shorts videos about it here : https://www.youtube.com/@EmmanuelGeveaux Or some posts about it here : https://www.linkedin.com/posts/emmanuel-geveaux-93836130a_labview-statemachines-ugcPost-746286803261... This toolkit will be Open-Source, free for students, education purpose and within LabVIEW Community Edition use. I'd be happy to ear any feedback on those videos and posts. Best regards Emmanuel

This year I went to NI Connect (the new NI Week) for the first time in 7 years. I thought I would be the exception and see all those that have gone year after year. But it turns out that many of us this was our first year back, or some last year was their first year back since COVID. In general I think this is a good sign, that things are moving in the right direction. NI has some new leadership that has a LabVIEW focus, and at least at the moment appear to want to push adoption. Reversing the subscription only is a welcome change, but for many it hurt the inertia of business. Once a ship starts moving in the wrong direction it takes a while to come back. Or put another way, respect is lost in buckets and gained in drops. Plenty of businesses have likely moved away from LabVIEW and NI because of poor decisions, that in my opinion, were so NI would look more valuable for an Emerson sale. I'm in the Detroit area, and plan to retire doing LabVIEW. At the moment I think I can do that. Not long ago I didn't think that would be the case. We were just blindly paying the SSP each year. The subscription only model, made management here reevaluated things. We took a few years off. Then perpetual licenses came back again so we renewed. I think we will likely get a new perpetual license every 4 years or so. This will hurt NI since this means less users on the newest release finding issues. Building back trust will take time here, and this will likely play out in a similar way around the world for other companies.

It is not that LabVIEW MAY unregister the reference, but that it WILL unregister the reference as soon as the top level VI in whose hierarchy the reference was created goes idle. This is by design and the only way to prevent that is to either keep that hierarchy active until any other user of that refnum has finished or delegate creating of the refnum to the place where it is needed, for instance through a LV2 style global maintaining the reference in a shift register and when being called for the first time it will create the refnum if the shift register contains an invalid refnum. True Actor Framework design kind of mandates that all refnums are created in the context of where they are used not some other global instance that may or may not keep running for the time some Actor is using the refnum.

Hi everyone, Just want to share our open source project "Labview Python Bridge". Connect labview apps with python apps in realtime with multi-processing data queues. https://github.com/jmor2000/labview_python_bridge If anyone has any questions or suggestions for new developments / features, let me know. Cheers Jeff

Absolutely echo what Shaun says. Nobody banned them. But most who tried to use them have after some more or less short time run from them, with many hairs ripped out of their head, a few nervous tics from to much caffeine consume and swearing to never try them again. The idea is not really bad and if you are willing to suffer through it you can make pretty impressive things with them, but the execution of that idea is anything but ideal and feels in many places like a half thought out idea that was eventually abandoned when it was kind of working but before it was a really easily usable feature.

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:

If I had to do it static at compile time my choice would be to have a Create xxx vi for every class that needs to be creatable. I don't like the class constant on the diagram at all.

I'll caveat this with this is only my opinion as a European. Market forces may be completely different to my perception in the US. When I first started, LabVIEW was basically a loss-leader to sell hardware. The sales people would give it away free (or heavily discounted) if you bought the hardware. It proliferated and people like myself learnt and expanded our capabilities. Over time it launched a small consultancy industry specialising in LabVIEW. There were a few major successes such as JKI and some partnerships along with single developer consultants. The test and measurement industry had few rivals to LabVIEW's capabilities. Fast forward to today and I think the emphasis is now firmly on large organisations with enormous hardware requirements-in particular governmental organisations. CERN is an obvious one in Europe (CERN being intergovernmental) but I believe there are many in the US. The Test and Measurement was, for the most part, lost to Python and although there are one or two consultants still operating in my neck of the woods, that part of the industry is basically gone here. So. In my view there is still an appreciable number of opportunities working for large companies' in the US and Europe but if you are looking to be a self employed contractor (in Europe) then you would be better off with something else.

I think there is a future and NI has significantly increased their activity and promotion for it (I guess one could be sarcastic and say that considering that NI's promotion of LabVIEW and active support of the community was pretty much zero just 3 years ago, anything more than zero is significant). It will however not reach the stage that Dr. T once optimistically proposed as "LabVIEW everywhere". But that is not necessary. LabVIEW has still some interesting features and advantages and there won't be any programming environment ever that suits everybody. The license change is welcome but not to significant, I think, as the new(old) perpetual license is basically quite beyond reasonable in my opinion. LabVIEW was expensive in the old days already but the new perpetual license cost is in my opinion simply to high (it's more than double of what it was before they tried to force feed the subscription). If I had to pay it myself, I would most likely stop with LabVIEW and simply use the Community Edition as a hobby. However, you should anyhow never build your future on just one leg. LabVIEW can be an interesting and even viable option, but with LabVIEW alone you never could and never will be able to earn a keeping. You need additional expertise. LabVIEW shines in combination with hardware control, so having a good understanding on electronics, electricity, communication protocols, interoperability with other systems is what makes you stand apart in a world of other programmers. The actual world doesn't run on blockchain, LLMs, marketing and stock exchange, even if that seems what a large amount of people believe, since it promises quick profits. But the hype of today is the old story of tomorrow, since there is already another hype to chase then. Almost all the AI hypers on social media today, were trying to peddle their cr*pto hype a few years ago, and will all quickly move to the next hype once AI has been falling down from the hype (which it actually has done already more than once in the past, but most people seem to have a short memory or simply haven't been around long enough to remember). Of course, I have about 10 more years I need to look forward too, so for me it is quite easy. There is enough of LabVIEW around to keep me full time busy with that until then, (but I like to also do some hardware and luckily can do that too). For someone younger, you definitely need to have some options open.

参考 https://www.vipm.io/publisher/opengds/ OpenGDS UML Editor by OpenGDS

In case anyone else runs into the issue...

Available in the new ECL version 4.6.0

I tried hard to ignore your poisonous whisperings but eventually succumbed to it. 🤫

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

Reentrant execution may be a safe option. Have to check the function. The zlib library is generally written in a way that should be multithreading safe. Of course that does NOT apply to accessing for instance the same ZIP or UNZIP stream with two different function calls at the same time. The underlaying streams (mapping to the according refnums in the VI library) are not protected with mutexes or anything. That's an extra overhead that costs time to do even when it would be not necessary. But for the Inflate and Deflate functions it would be almost certainly safe to do. I'm not a fan of making libraries all over reentrant since in older versions they were not debuggable at all and there are still limitations even now. Also reentrant execution is NOT a panacea that solves everything. It can speed up certain operations if used properly but it comes with significant overhead for memory and extra management work so in many cases it improves nothing but can have even negative effects. Because of that I never enable reentrant execution in VIs by default, only after I'm positively convinced that it improves things. For the other ZLIB functions operating on refnums I will for sure not enable it. It should work fine if you make sure that a refnum is never accessed from two different places at the same time but that is active user restraint that they must do. Simply leaving the functions non-reentrant is the only safe option without having to write a 50 page document explaining what you should never do, and which 99% of the users never will read anyways. 😁 And yes LabVIEW 8.6 has no Separated Compiled code. And 2009 neither.

A Timestamp is a 128 bit fixed point number. It consists of a 64-bit signed integer representing the seconds since January 1, 1904 GMT and a 64-bit unsigned integer representing the fractional seconds. As such it has a range of something like +- 3*10^11 years relative to 1904. That's about +-300 billion years, about 20 times the lifetime of our universe and long after our universe will have either died or collapsed. And the resolution is about 1/2*10^19 seconds, that's a fraction of an attosecond. However LabVIEW only uses the most significant 32-bit of the fractional part so it is "only" able to have a theoretical resolution of some 1/2*10^10 seconds or 200 picoseconds. Practically the Windows clock has a theoretical resolution of 100ns. That doesn't mean that you can get incremental values that increase with 100ns however. It's how the timebase is calculated but there can be bigger increments than 100ns between two subsequent readings (and no increment). A double floating point number has an exponent of 11 bits and 52 fractional bits. This means it can represent about 2^53 seconds or some 285 million years before its resolution gets higher than one second. Scale down accordingly to 285 000 years for 1 ms resolution and still 285 years for 1us resolution.

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.

😅 You might be waiting a while, I'm mostly interested in compression, not decompression. That being said in the post I made, there is a VI called Process Huffman Tree and Process Data - Inflate Test under the Sandbox folder. I found it on the NI forums at some point and thought it was neat but I wasn't ready to use it yet. It isn't complete obviously but does the walking through of bits of the tree, to bytes. EDIT: Here is the post on NI's forums I found it on.

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.

I haven't had much time to investigate this until this month, but I think I've found the cause. XNodes on the production computer were not designed optimally. In the AdaptToInputs ability I was unconditionally passing a GenerateCode reply, thinking that the AdaptToInputs is only called when interacting with the XNode (connecting/disconnecting wires). It turned out that LabVIEW also calls the AdaptToInputs ability once, when the VIs are loaded and any single change is made, no matter if it touches the XNode or not. As I had many such non-optimal XNodes in many places, it was causing code regeneration in all of them. Besides of that some of my VIs had very high code complexity (11 to 13), because of a bunch of nested structures. When the XNodes regeneration was occurring simultaneously with the VIs recompilation, it was taking that a minute or so. After I added extra conditions into my AdaptToInputs ability (issue a GenerateCode reply only, when the Term Types are changed), the edits in my VIs started to take 1.5 seconds. Still the hierarchy saves can be slow, when some 'heavy' VIs are changed, but it's a task for me to refactor those VIs, so their complexity could decrease to 10 or less. By the way, my example from the previous page was not suitable for demonstrating the situation, as its code complexity is low and the Match Regular Expression XNode does not issue a GenerateCode reply in the AdaptToInputs.

I have always used this library to prevent the screensaver and windows lock from occurring. Our IT locks down the computer so the screensaver, lock screen, cannot be changed. This library bascially tells Windows it's in Presentation mode, e.g., slideshow, watching a movie, etc, such that the screen will not got to screensaver or lock screen.

My problem was on a windows machine but I managed to solve it; I found that using LVCompare also segfaulted on the same file, but did not segfault with the -nofp command line option. With this I was able to confirm the specific file that both LVMerge and LVCompare were segfaulting on, and systematically delete half the code and re-test whether LVCompare would crash. After a few hours I was able to track down the offending piece of code to a random chart; I'm honestly still not sure what was causing them to segfault, but deleting and replacing the chart fixed the issue. Hope this helps someone else out there!

This toolkit offer you an efficient, stable, and reliable front panel control value refresh function. User can design their UI dashboard without any code development. 1. Powerful parallel execution capability, Support clone reentrant execution running mode, you can create multi dashboard UIs at the same time and controls can synchronous refresh across different UI. 2. High-speed data refresh capability, even with thousands of controls on a single UI, can easily maintain a refresh rate of 50ms while consuming very little CPU resources. 3. Support all control data types that "Tag Engine" support, this mean the only thing you need to do is to change the control "Label" with "Tag name", then the control will refresh automatically. 4. Support "muParser Expression", you can type the control "Label" with "Expression" that muParser Expression support, For example "a + b" "a > 1 & b >= 2".

I am also rocking version 4.2.0b1-1 for the same reasons.

I would suggest rabbitmq, i want(ed) to present it at a LabVIEW user group (LUGE) but haven't done it yet. It's very powerful. I use redis and did a quick presentation (in french) at LUGE recently, i haven't used the stream feature though, I only used it as cache.

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.

When you send the message you encapsulate the message as a cluster of string and variant. You don't seem to unwrap the variant from the name/variant cluster in the receiver. What I expect to see is something like this in the receiver:

Well, yes and no and yes and maybe. It all depends on what you're trying to measure and what the system requirements are. And, of course, just because it's cheaper up front doesn't mean it's cheaper overall. If it costs $200 less but takes me 50 hours longer to implement then it costs more.

Regarding Levenshtein: Wladimir Levenshtein developed 1995 an algorithm for this. It is called the Levenshtein Distance. Some years ago I developed a VI to calculate the Levenshtein Distance. Here it is (LabVIEW 2016). Can you post your VIs in LV2020 or 2019, please. Levenshtein Distance.vi

Another VI I thought someone reading this forum thread might find helpful. This one calls the one I posted previously as a subVI. "Make Control Glow.vi" draws a fading rectangle behind the specified control. Save it and its subVI ("Offset Glow Rect.vi") to the same subdirectory. For example, here's a glow on a system OK button. Color and border thickness are parameterized. Saved in LV2020. Make Control Glow.vi Offset Glow Rect.vi

Not from NI, that I know of. I did make a similar API that wraps the Qt framework. That involves creating external windows though; your toolkit has the benefit of being integrated with VI front panels. Original LAVA post: https://lavag.org/topic/19611-utf-8-text-svg-images-inheritable-gui-components-dynamically-composed-guis-layout-management-splitters-in-tabs-mdis-taskbar-integration-and-much-more/ NIPM installation instructions: https://jksh.github.io/LQ-Bindings/docs/ As Mikael and Rolf said, class constants are not needed: Definitely! LabVIEW's built-in support for dynamic GUIs is very poor. NXG was starting to show some promise with dynamic controls, but that's now dead. So, community-built tools are sorely needed. Are you planning to make public releases of your work? Layouts are common concept in a wide variety of GUI toolkits. Makes it so much easier to create resizable GUIs and support a variety of screen resolutions.

This seems to work... CRC16-CCITT-FALSE.vi

Well that's okay I felt like doing some improvements on the image manipulation code. Attached is an improved version that supports ico and tif files and allows to select an image from within the file. For ico files it basically grabs the one image you select (with Image Index) and make an array of bytes that is a ico file with only that image in it, and then displays it in the picture box. For Tif files there is a .Net method for selecting the image which for some reason doesn't work on ico files. Edit: Updated to work with Tifs as well. Image Manipulation With Ico and Tif.zip

Thanks Mads.

You *can* use DETT on built applications, just enable VI server access and debugging in the build. Here is a description of it: http://digital.ni.com/public.nsf/allkb/A50A8BBFD737679186257D7700688757

I used scripting and low-level VI editing to generate a VI with every single decoration object in LabVIEW, at least those with ID's 0 to -4096. There may be some out of that range (and many in that range don't have a valid image associated with them) but this range contains a lot of them. 0 to -4096.vi

Looks like someone beat me to it! Oh well, I already exported it (also for 2009, incidentally) so I'll post it here in case it'd be more convenient to use a regular VI file. 0 to -4096.vi

Basically you need 2 more Property nodes if you want to keep your headers color. you must do what QueueYueue said first. Then : Active Cell.Active Column Number = -2 (this selects all columns) Active Item.Row Number = -1 (this selects the column headers) Active Cell.Background Color = Desired color Then : Active Cell.Active Column Number = -1 (this selects row header) Active Item.Row Number = -2 (this selects all rows) Active Cell.Background Color = Desired color

Hi All, I'm looking for a good resource that explains LabVIEW's Execution System / Thread Allocation / Thread Priority system. As a background to the reason for my request: I have an application with over 50 parallel loops running at fixed but configurable times. Twenty of these loops are calling a .net Dll and are thus not in a Timed Loop (there is a known issue according to NI support with calling a .net dll in a timed loop where the call time is large ie. upwards of a second). The remaining loops are performing other data acquisition. Each loop is what I call a Task Controller - it looks after a specific piece of hardware, taking requests for data (via queues), performing data acquisition and then pumping the result back to the requester. In order to seperate the timing of the functionality (and allow multiple requesters access to the same data), this process is not sequential but occurs in parallel loops. So there is a lot of parallel activity going on. I notice that as more of these loops fire up, the slower the remaining loops are. The CPU usage tends to stay around 7-8% during this time irrespective of how many loops are executing. Note that the .net dll calls (up to 20) are reasonably slow calls and each could take up to 6 seconds to execute. The .net dll has been written to handle multi-threading. The PC is a hyper-threaded quad core (ie 8 logical cores) @ 3.3GHz. Kinda a meaty machine. I should also mention that the majority of the VIs are re-entrant. The only non-rentrant VIs are some FGVs and a few User Interface VIs that reference the data in these FGVs. And before you ask the FGVs are simply Get/Set for a handful of cluster points. So I figure it's a simple case of thread starvation. Every VI is currently set to the Standard Execution System (via Same as Caller) with Normal Priority. I figure that adjusting these settings on the top level Task Controller vis may assist in spreading the load to the remaining available, but not executing, threads. The SubVIs under each Task Controller will continue to use the Same As Caller setting, allowing me to seperate logically each Task into appropriate Execution Systems. Any thoughts?

The OpenG Pipe Project does just that. It is a LabVIEW Library that replaces the System Exec function and returns pipe refnums for the three standard IO interfaces and functions to read and write to those refnums. The project hasn't been released yet as I consider it not entirely release quality but it does work for me and I have actually used in in several of my projects already. Since there is no officially released package yet you can't just download it through VIPM from internet. But here is a copy of a package you can install using VIPM. oglib_pipe-1.0-1.ogp