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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"

Many years ago I made a demo for myself on how to drag and drop clones of a graph. I wanted to show a transparent picture of the new graph window as soon as the drag started, to give the user immediate feedback of what the drag does and the window to be placed exactly where it is wanted. I think I found inspiration for that on ni.com or here back then, but now I cannot find my old demo, nor the examples that inspired me back then. Now I have an application where I want to spawn trends of a tag if you drag the tag out of listbox and I had to remake the code...(see video below). At first I tried to use mouse events to position the window, but I was unable to get a smooth movement that way. I searched the web for similar solutions and found one that used the Input device API to read mouse positions to move a window without a title and that seemed to be much smoother. The first demo I made for myself is attached here (run the demo and drag from the list...). It lacks a way to cancel the drag though; Once you start the drag you have a clone no matter what. dragtrends.mp4 Has anyone else made a similar feature? Perhaps where cancelling is handled too, and/or with a more generic design / framework? Drag window out of listbox - Saved in LV2018.zip

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.

Apparently they moved it under Visible Items Edit: This also affects other types of structures.

Well, there are two aspects. The first is the technical one from hackers diving into the software and unhiding things that NI felt were not ready for prime time, to complicated for simple users, or possibly also to powerful. The main reason definitely always is however: if we release that, we have to spend a lot more effort to make it a finished feature (a feature for internal use where you can tell your users: "sorry that was not meant to be used in the way you just tried") is maybe 10 - 20% of development time than the finished feature for public use. There is also support required. That costs money in terms of substantial extra development, end user quality documentation (a simple notepad file doesn't cut it), maintenance and fixing things if something does not match the documented behaviour. And yes I'm aware they don't always fix bugs immediately (or ever) but the premise is, that releasing a feature causes a lot of additional costs and obligations, if you want to or not. The other aspect is, if someone who is an active partner and has active contacts with various people at NI, he is infinitely more likely to be able to influence decisions at NI than the greatest hacker doing his thing in his attic and never talking with anyone from NI. In that sense it is very likely that Jim having talked with a few people at NI has done a lot more to make NI release this feature eventually, than 20 hackers throwing every single "secret" about this feature on the street. In that sense the term "forcing NI's hands" is maybe a bit inaccurate. He didn't force them, but led them to see the light! Not out of pure selfless love, but to be able to officially use that feature for himself. The according Right-Click framework was a proof of concept to see how this feature can be used and mainly an example to other users how it can be used, and indeed once it worked it had fulfilled its purpose. That it was not maintained afterwards is not specifically JKI's fault. It is open source, so anyone could have picked up the baton, if they felt it was so valuable for them. The problem with many libraries is actually, if they are not open source and free, many complain about that, if it is open source and/or free, they still expect full support for it! In that sense I have seen a nice little remark recently:

Well, you are missing some important details in "The story of how this came about". So maybe indeed "it is worth a post of its own". It was LabVIEW 7.0 where they forgot to put a password on one of the VIs shipped with LabVIEW. And that VI had some node(s) on its block diagram including, I think, the BD reference property for the VI class. The community indeed got excited. But what did NI do? They tried to hide everything again in LabVIEW 7.1! I made a joke then that "our mother" NI must had had a PMS so she put the most interesting toys on a top shelf. So I made a"ladder" for us, kids, to get to them again and called it hviewlabs was me then, because that was a name of my company I used to sell my LabHSM Toolkit, an actor framework with actors controlled by hierarchical state machines (statecharts), long before the Statechart toolkit by NI, "THE Actor Framework", DQMH, and even before LVOOP. After PJM_Labview has published his private class generator http://forums.lavag.org/index.php?showtopic=307&hl=# and class hierarchies http://forums.lavag.org/index.php?showtopic=2161# and http://forums.lavag.org/index.php?showtopic=314&hl=hierarchy# (neither topic is available anymore) it became clear how to get access to private classes, properties and methods. However, it wasn't convenient enough. My PMS Assistant made it really easy. It gave back the access to those features to a much wider community of LabVIEW enthusiasts As you can see from the PMS topic discussion, by that time brian175 already had made his DataAct Class Browser. And he got really excited about the possibility not only browse but also to actually create objects, property and method nodes with the properties and method NI didn't want the users to see. By April of the same 2006 he figured out object creation too and incorporated the capabilities of PMS Assistant into DataAct Class Browser. At that point, I guess, NI decided that "the cat is out of the bag" and there is no point to resist. Nevertheless even after VI Scripting was made released by NI some classes, and even some properties and methods of public classes remain hidden even in LabVIEW 2024. I wonder why DataAct Class Browser is no longer available (as of January 2025) as well as original findings by PJM_Labview even here, on LavaG. Did NI "politely asked" admins to remove all that and just forgot about my PMS Assistant?

The Weather Station example that ships with LabVIEW shows a bit of this. but the data is not Base64, its just a pure characters,

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.

@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

I don't know what drivers are used under the hood, but I've recently used G-Audio to interface to the mic/speakers for a LabVIEW application I was working on.

Thanks, I'll be honest, I'm allergic to Discord. Vehemently so. To the point where I refuse to use it. Just seems like a lot of unfiltered noise to this old man. I'm gonna play with NodeRed and see if it's the tool of choice. And oh, back in the day I was a National Instruments Alliance Member. Dunno if that's still a thing or not. Cheers,

I posted a demo set of VIs here which can pop up a window, centered on whatever monitor the mouse is on. There's also settings to have the window center on the mouse wherever it is, but saying on the same monitor. And yes this uses the All Screens, Working Area properties.

There is an Application property called Display->All Monitors. It will give you the pixel ranges of the monitors in your system. What I've done is to use the calling VI's position to figure out which monitor it was on and then place the new VI window as needed. You could use a win32 dll call to get the mouse position as well if that better meets your requirements.

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:

Some people might be tempted to use Obtain Queue and Obtain Notifier with a name and assume that since the queue is named each Obtain function returns the same refnum. That is however not true. Each Obtain returns a unique refnum that references a memory structure of a few 10s of bytes that references the actual Queue or Notifier. So the underlaying Queue or Notifier is indeed only existing once per name, BUT each refnum still consumes some memory. And to make matters more tricky, there is only a limited amount of refnum IDs of any sort that can be created. This number lies somewhere between 2^20 and 2^24. Basically for EVERY Obtain you also have to call a Release. Otherwise you leak memory and unique refnum IDs.

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) 😁

@Rolf Kalbermatter the admins removed that setting for you as everything you say should be written down and never deleted 🙂

If the child classes are statically linked in the code (via class constants, or whatever other mechanism you use), then this approach should always work, because the child classes will always be in memory.

I kind of liked this idea and wished VIM's could allow for such a backpropagation. Even had a thought of making an idea on the dark forums. But then I played a while with the Variant To Data node. It doesn't play well. It can't determine a sink, if a polymorphic VI is connected or even when a LV native (yellow) node is connected. Borders of structures are another issue, obviously. So, it'd require making two ideas at least: to implement VIM backpropagation and to enhance the Variant To Data node. (As a hack one could eliminate the Variant to Data in their code with coerceFromVariant=TRUE token, but then the diagram starts to look odd and no error handling is performed). If someone still wants the code, shown in the very first post, it's here: https://code.google.com/archive/p/party-licht-steuerung/source/default/source?page=3 (\trunk\PLS-Code\PLS Main.vi). And these are the papers to progress through the lessons: LabVIEW Intermediate I Successful Development Practices Course Manual. Nothing interesting there for an experienced LV'er though. XNodes demonstrated here work a way better, and could be a good alternative (if you're OK with unsupported features, of course). As I tried to adapt them for my own purposes, I decided to improve the sink search technique. It surprised me a bit, that there's still no complete code to walk through all the nested structures to determine a source/sink by its wire. Maybe I didn't search well but all I found was this popup plugin: Find Wire Source.llb. It stops on Case structures though. I have reversed its logic to search for a sink instead of a source and tried to apply recursion, when it encounters a Case structure. Well, it's still not ideal, but now it works in most my cases. There are some cases, when it cannot find a sink, e.g. wire branches with void terms: Too many scenarios to process them all. Nevertheless, this little VI might be useful for someone. You may use it as a popup plugin, of course, or may pull out that Execute Find Wire Destination (R).vi and use it in your XNodes. As an example: Find Wire Destination.llb Already tried such nodes in a work project. I must admit that not all the time back-propagation is suitable, so about 50/50. But when it's used, it works.

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

The popular serializer/deserializer problem. The serializer is never really the hard part (it can be laborious if you have to handle many data types but it's doable) but the deserializer gets almost always tricky. Every serious programmer gets into this problem at some point, and many spend countless hours to write the perfect serializer/deserializer library, only to abandon their own creation after a few attempts to shoehorn it into other applications. 🙂

It feels strange to me too. As I understand it, the "no merge" clause makes libraries legally unusable by others. A quick search reveals that the "no merge" clause is found in numerous different software licenses: https://www.google.com/search?q="merge+the+Software+into+any+other+software" My best guess is that the clause was originally written for standalone applications (meaning that you're meant to run the software as-is, without copying its source code into your own, or linking your own software to its binaries). However, somewhere along the way the clause got copied directly into a library license, without the involvement of a lawyer who understands software licensing. Perhaps @mabe can clarify? He helped at:

I actually had a similar experience when first moving everything to the new OpenG structure. It broke heaps of stuff (even inside its own OpenG stuff), so I rolled back the change. Some time later I tried again, and think I did have to deal with a bit of pain initially with relinking or maybe some missing stuff, but since then things have been stable.

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)

To be honest, I always thought those should be in the Visible Items menu.

Makes sense. It just goes to show how ingrained workflows are and little things can trip you up. I was right-clicking over the N, over the I. Right clicking 2 pixels down/up from the edge. Top edge, bottom edge, left right.

Probably not the feedback you are expecting but we really should do something about the nasty root loop API calls in the input API. I have somewhat progressed with this over the years and have the windows stuff all working for mouse and keyboard (and a little of the Linux) but I don't have a Mac so can't do anything on that. If there is some interest then let me know and I will see if I can allocate time to getting an API together.

To analyze large time series remotely I have a client application that splits the data transfer using two methods; It will break down the periods into subperiods that is then assembled into the full period by the receiver *and* if the subperiods are too large as well they are retrieved gradually (interlaced) by transferring decimated sets with a decimation offset. So, as a result of this I need to merge multiple overlapping fragments of time series (X and Y array sets). My base solution for this just concatinates two sets, sorts the result based on the time (X values) and finally removes duplicate samples (XY pairs) from it. This is simple to do with OpenG array VIs (sort 1D and remove duplicates VIs) or the improved VIM-versions from @hooovahh, but this is not optimal. My first optimized version runs through the two XY sets in a for-loop instead, a for loop that picks consecutive unique values from either of the two sets until there are no such entries left. This solution is typically 12-15 times faster than the base case (<10 ms to merge two sets into one set with 250 000 samples on my computer e.g.). Has anyone else made or seen a solution for this before? It is not as generic as the array operations covered by the OpenG array library e.g., but it still seems like something many people might need to do here and there...(I had VIs in my collection to stitch consecutive time series together with some overlap, but not any that handles interlacing as well). It would be interesting to see how optimized and/or generalized it could be solved. I have attached the two mentioned examples here , they are not thorougly tested yet, but just as a reference (VIMs included just in case...). Below is a picture of the front panel showing an example of the result they produce with two given XY sets (in this case overlapping samples do not share the same value, but this is done just to illustrate what Y value it has picked when boths sets have entries for the same X (time) value): Merging XY series LV2022.zip

In the LabVIEW community a phrase that has been used to describe undocumented, or incomplete features of LabVIEW has at times been called Rusty Nails. In searching LAVA it appear this is never explained and so this post is intended to give a brief history with as many details as I know having not been active when this all took place. The earliest reference to "Rusty Nails" found online (thanks to AQ) is by Greg McKaskle of NI in 1999. Someone was asking about all the undocumented INI settings that could be found, and how some weren't exposed to the Tools >> Options dialog. Greg's reply was this: Back in the LabVIEW 5.x and 6.x era there was a new emerging technology that was LabVIEW Scripting. NI had created scripting for their own purposes but the community saw it and wanted to be able to automate editing, or creating LabVIEW code. With the help from Jim Kring and others, the basic tools for enabling scripting in LabVIEW were available. The story of how this came about is worth a post of its own, but the summary is that NI shipped a VI that didn't have a password on the block diagram, which allowed for the creation of any object, given an ID. Using a for loop, you could easily create every object in LabVIEW, including objects which facilitate in creating and manipulating code. Discussing scripting often leads into discussing other INI keys which enable private functions like the well known SuperSecretPrivateSpecialStuff. It is possible this is one of the keys Greg was referring to. Other INI keys from 5.x can be found here. After these discoveries the NI forums started getting users asking about scripting, and private functions. Users were looking for help, and documentation but NI wasn't ready for this knowledge to be public and so they started deleting all posts related to private, and scripting functionality. Some of the motivation for the creation of LAVAG came about by a desire to have an independent place to discuss the LabVIEW topics that NI didn't want to have on the public forums, potentially adding to the number of support calls, and confusing new users with advanced topics that were undocumented or incomplete. After LAVA's creation a subforum section was labeled Rusty Nails, and intended to be a place to discuss Scripting, ExternalNodes, XNodes, Private methods, and general LabVIEW hackery. Over the years several private functions have been made public, and scripting has become an official feature shipping with LabVIEW. Because of this the Rusty Nails and XNodes subforums were combined into what is now the VI Scripting section. Even over on the official NI forums, discussions about private functionality and XNodes has been relaxed since those early days. Asking for private methods and getting unofficial help is something users, and sometimes NI employees will participate in, without the heavy censorship seen earlier. And topics of scripting are encouraged now that the feature has been official since LabVIEW 8.6. If you have anything you'd like me to add regarding scripting's history feel free to reply and I can add it. And if I got any of the details wrong let me know. Again I wasn't around when this all took place and I've just tried putting down the details I've heard from other developers.

This is by no means a full EtherCAT tutorial but, rather, introductory notes. Please, feel free to add to this post, expend and/or correct any mistakes and information.

Yes this has been done before. I believe BlueVariantView is what you are looking for. It creates a recursive tree of any data type: JSONtext on the other hand illustrates how to turn your data back into a data type.

I can confirm that LabVIEW 2018 SP1 f4 (32-bit) automatically selects LabVIEW Runtime 2018 SP1 f5 when "automatically select recommended installers" is checked and LabVIEW Runtime 2018 SP1 f5 is installed. Though, it does not ask for the installer source. There used to be SFX installers that were extracted to "C:\National Instruments Downloads". When such an installer was used, the destination folder must not be deleted as it is used as a source location when creating installers in LabVIEW. Perhaps you installed the runtime engine through an old SFX installer and deleted those files at some point?

@Ravi Beniwal, I have the same problem, VIPM reports that missing dependency for me too. If it isn't required could it be removed ? If it is required could it be included ? I suspect it is included in version 1.7.028 which does not report the error. I spent(wasted !) time looking for the dependency and downloading it, only to realise it might not be needed as it launches OK from the LV IDE menu Tools\LabVIEW Task Maanger.... Peter

MAT files are now just H5 files(HDF). Look at the library https://h5labview.sourceforge.io/ and find the example for writing a MAT file. You just need to add a special header in the beginning. I assume the dlls needed will work on Windows server, but am not sure.

It's easy, there is probably a vi with that name in memory, so if you would remove the class prefix there would be a conflict. Rename the vi first to something unique and the try to delete it.

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

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

Sweet! That solves it. So, now we can write a LabVIEW console app! Here is the VI that let's you write to the StdOut of the calling console: Write to StdOut of Calling Parent.vi -John