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  1. 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
    5 points
  2. 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...
    3 points
  3. 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!
    3 points
  4. 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"
    3 points
  5. 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
    2 points
  6. 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.
    2 points
  7. 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.
    2 points
  8. 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
    2 points
  9. 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.
    2 points
  10. 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.
    2 points
  11. Look at this new download on VIPM https://www.vipm.io/package/bjm_lib_request_power/
    2 points
  12. 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
    2 points
  13. 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:
    2 points
  14. If you have a specific structure for your chambers (ie everybody is under the "Hooovahh Chamber" directory), you could do a simple lookup and use the Get LV Class Default Value to dynamically load the classes. I do something similar with my HAL already, except I dictate what class to load based on a JSON file.
    1 point
  15. I used LabVIEW to develop a toolkit for ATE software. The toolkit is called "Test bench Framework", which includes a test sequence editor and a test engine.This toolkit features the ability to execute several different sequences in parallel.If you are interested in this kit please contact me, thank you! This toolkit is over 10MB in file size and cannot be published on VIPM, so I uploaded it to Github.Test-Bench-Framework . I used the TestStand icon inside my own sequence editor and wondered if there would be any copyright issues involved.But it's not commercially available yet.
    1 point
  16. @Rolf Kalbermatter my team and I still use in some systems here! In fact this very last week we have needed to add some lua stuff to an old project.
    1 point
  17. 1 point
  18. Found it here @Ajayvignesh https://github.com/sandialabs/LVTM
    1 point
  19. 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.
    1 point
  20. 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.
    1 point
  21. 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.
    1 point
  22. So in LV>=20, using OpenSerializer.Base64 and G-Image. That simple. Linux just does not have IMAQ. Well, who said that the result should be an IMAQ image?
    1 point
  23. 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
    1 point
  24. 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?
    1 point
  25. You might have more success posting this on the Discord. Most of the conversations happen there these days.
    1 point
  26. 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,
    1 point
  27. 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".
    1 point
  28. I think this is fixed now. Please check.
    1 point
  29. 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.
    1 point
  30. 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.
    1 point
  31. Discussion forums like LAVA and ni.com are challenged these days by LLMs that can answer in a well structured manner very quickly and handle follow-up questions on the spot. Forums have their stenghts, but when it comes to basic questions that LLMs can find a lot about, spread across multiple forums, the LLMs win. It is a bit of a catch 22 though, as the LLMs need the forums alive to stay up to date 😮 ------------------------------ Here is Grok answering you question of what a DVR is: DVRs as References: In LabVIEW, DVRs (Data Value References) are a mechanism to access data by reference rather than by value. This means that instead of creating copies of the data (as is typical in LabVIEW's dataflow paradigm), a DVR provides a pointer-like reference to a single memory location where the data resides. This avoids unnecessary data duplication, which can be critical for large datasets or performance-sensitive applications. Avoiding Copies: By using DVRs, you can manipulate the same data in memory without creating copies, which is especially useful for large arrays, clusters, or other complex data structures. This reduces memory usage and improves performance. Parallel Operations and Race Conditions: When multiple parallel operations (e.g., parallel loops or VIs) access the same DVR, there is a potential for race conditions if the access is not properly synchronized. LabVIEW provides the In-Place Element Structure to safely access and modify DVR data. This structure ensures that only one operation can read or write to the DVR at a time, preventing race conditions. Without this, simultaneous read/write operations could lead to unpredictable results or data corruption. Key Points to Add: Thread Safety: DVRs are not inherently thread-safe. You must use the In-Place Element Structure (or other synchronization mechanisms like semaphores) to avoid race conditions when multiple parallel tasks access the same DVR. Use Cases: DVRs are commonly used in scenarios where you need to share data between parallel loops, modules, or processes without copying, such as in real-time systems or when managing shared resources. Limitations: DVRs are only valid within the application instance where they are created, and the data they reference is freed when the reference is deleted or the application stops. --------------------- Before DVRs we typically had to resort to cloning of functional globals (VIs), but DVRs make this a little more dynamic and slick. You can have a single malleable VI operate on multiple types of DVRs too e.g., that opens up a lot of nice reuse. If you have an object that requires multiple circular buffers e.g. you can include circular buffer objects in the private data of that object, with the circular buffer objects containing a DVR to an array acting as that buffer... -------------------- Here is ChatGPT comparing functional globals with DVRs: Functional Globals (FGs) and Data Value References (DVRs) are both techniques used in programming (particularly in LabVIEW) to manage shared data, but they offer different approaches and have different strengths and weaknesses. FGs encapsulate data within a VI that provides access methods, while DVRs provide a reference to a shared memory location. Functional Globals (FGs): Encapsulation: FGs encapsulate data within a VI, often a subVI, that acts as an interface for accessing and modifying the data. This encapsulation can help prevent unintended modifications and promote better code organization. Control over Access: The FG's VI provides explicit methods (e.g., "Get" and "Set" operations) for interacting with the data, allowing for controlled access and potential validation or error handling. Potential for Race Conditions: While FGs can help avoid some race conditions associated with traditional global variables, they can still be susceptible if not implemented carefully, particularly if the access methods themselves are not synchronized. Performance: FGs can introduce some overhead due to the VI calls, but this can be mitigated by using techniques like inlining and careful design. Example: An FG could be used to manage a configuration setting, with a "Get Configuration" and "Set Configuration" VI providing access to the settings. Data Value References (DVRs): Shared Memory Reference: DVRs are references to a memory location, allowing multiple VIs to access and modify the same data. This is a more direct way of sharing data than FGs. Flexibility: DVRs can be used with various data types, including complex data structures, and can be passed as parameters to subVIs. Potential for Race Conditions: DVRs, like traditional globals, can be prone to race conditions if not handled carefully. Proper synchronization mechanisms (e.g., queues, semaphores, or action engines) are often needed to prevent data corruption. Performance: DVRs can be very efficient, especially when used with optimized data access patterns. Example: A DVR could be used to share a large array between different parts of an application, with one VI writing to the array and another reading from it. Key Differences and Considerations: Control vs. Flexibility: FGs offer more control over data access through their defined interface, while DVRs offer more flexibility in terms of the data types and structures that can be shared. Race Condition Mitigation: While both can be susceptible, FGs can be designed with built-in synchronization mechanisms (like action engines), while DVRs require explicit synchronization mechanisms to prevent race conditions. Performance Trade-offs: DVRs can offer better performance in many cases, especially when dealing with large data sets, but this can be offset by the complexity of managing synchronization. Code Readability and Maintainability: FGs can make code more readable and maintainable by encapsulating data access logic, but poorly designed FGs can also lead to confusion. In summary: Use Functional Globals when: You need controlled access to data, want to encapsulate data management logic, or need to ensure some level of synchronization. Use Data Value References when: You need to share data efficiently between multiple parts of your application, need flexibility in the data types you are sharing, or when performance is critical and synchronization can be handled externally. It's worth noting that in many cases, a combination of both techniques might be used to leverage the strengths of each approach. For example, a DVR might be used to share data, while a functional global (or an action engine) is used to manage access to that data in a controlled and synchronized manner.
    1 point
  32. 4. WinAPI version using ChooseColor function. NativeColors.rar Far from ideal, don't kick too hard. 🙂 Determine Clicked Array Element Index is from here.
    1 point
  33. Technically it is a resource collector, but not exactly in the same way typical garbage collectors work. Normal garbage collectors work in a way where the runtime system somehow tracks variables usage at runtime by monitoring when they get out of runtime scope and then attempts to deallocate any variable that is not a value type in terms of the stack space or scope space it consumes. The LabVIEW resource collector works in a slightly different way in that whenever a refnum gets created, it is registered together with the current top level VI in the call chain and a destroy callback with a refnum resource manager. When a top level VI stops executing, both by being aborted or simply executing its last diagram element, it informs the refnum resource manager that it goes idle, and that will then make the refnum resource manager scan its registered refnums to see if any is associated with that top level VI and if so, call its destroy callback. So while it is technically not a garbage collector in the exact same way as what Java or .Net does, it still is for most practical purposes a garbage collector. The difference is, that a refnum can be passed to other execution hierarchies through globals and similar and as such might still be used elsewhere, so technically isn't really garbage yet. There are three main solutions for this: 1) Don't create the refnum in an unrelated VI hierarchy to be passed to another hierarchy for use 2) If you do create it in one VI hierarchy for use in another, keep the initial hierarchy non-idle (running) until you do not need that refnum anymore anywhere. 3) If the refnum is a resource that can be named (eg. Queues, Notifiers) obtain a seperate refnum to the named resource in each hierarchy. The underlying object will stay alive for as long as at least one refnum is still valid. Each obtained refnum is an independent reference to the object and destroying one (implicit or explicit) won't destroy any of the other refnums.
    1 point
  34. 该文件中有四行头文件 (4 rows of header in this file) 下面是一个程序,它将读取四个标题行,然后每次读取其余的 100 行 read csv per chunk of 100 rows.vi
    1 point
  35. I'm excited to release ViPER ViPER is an Object Oriented design Framework that supports dependency injection and recursive object creation. Systems are assembled at runtime from a collection of pre-built components defined by an Object Definition Document. Please visit the project on GitHub https://github.com/kurtafriday/ViPER I've presented this framework at several GLA Conferences, for an overview and guidance please view. GLA 2021 https://labviewwiki.org/wiki/GLA_Summit_2021/Open_Source_ViPER GLA 2020 https://labviewwiki.org/wiki/GLA_Summit_2020/ViPER_-_A_LabVIEW_Dependency_Injection_Framework This branch of ViPER has been used by us to develop systems in regulated industries for several years, it's solid and reliable, however its windows only. I'm working on ViPER_WinRT which is compatible with Windows and RT and we have already used it for several systems. I'll be releasing ViPER_WinRT in the coming months. I'll work to get ViPER onto the VIPM Tools Network soon. I'm looking forward to the feedback and I hope you enjoy and get value from this framework. Ping me if you have any questions. kurt@medulla.net
    1 point
  36. We use the MPSSE.dll LABview driver from Benoit. We are trying the i2c read 1 byte and multi bytes. We expect ack for all bytes except the last byte with nak. During read, we understand that the I2C master drives the ack/nak. However, ack and nak happens randomly. Any body have any suggestions Thank you Dan
    1 point
  37. 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
    1 point
  38. 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.
    1 point
  39. 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.
    1 point
  40. Version 1.0.0

    564 downloads

    This tool-set gives access to all the 1-wire TMEX functionality. I was able to access 1-wire memory with this library. It has all the basic VI to allow communication with any 1-wire device on the market. It needs to be used in a project so the selection of the .dll 64 bit or 32 bit is done automatically. It works with the usb and the serial 1-wire adapter.
    1 point
  41. 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.
    1 point
  42. 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
    1 point
  43. I think I have this fixed. Tried a compiled version of the transport library; this worked without issue. I made the timeout changes, which did not seem to have an impact on performance. I then recompiled everything (the server-side code is used in multiple applications on the system); the delay I was seeing with the one message/response went to expected amounts in tests. I've been waiting to test this with the whole system up and going; unfortunately, we've been battling drive issues that are stopping everything else. Can't definitively say it's fixed. Can't point to a smoking gun. I'm appreciating this forum and the people on it right now.
    1 point
  44. Mwuhahahahaha! Three config tokens have escaped your grasp! I modified them specifically for folks like Flarn! They don't appear as plain text anywhere in the EXE (or in any VI for that matter). Do they guard any great secret of LabVIEW? I'm not telling! But you can have fun pouring through the code and looking for interesting bits and trying to figure out what you need to put in your config file. LabVIEW 2013 or later. Good luck.
    1 point
  45. 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?
    1 point
  46. 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
    1 point
  47. 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
    1 point
  48. QUOTE(Tomi Maila @ Oct 30 2007, 01:34 AM) GetValueByPointer takes the C style pointer and the corresponding data type, which are generated by Import Shared Library Tool, as inputs and copies the value which the pointer points in shared library(dll/so/framework) to LabVIEW. Input terminals: Input Type: Input type is the LabVIEW data type to which you want to pass into LabVIEW. Input type can be Numeric, string, Array, Cluster . This VI returns an error if LabVIEW cannot convert the data wired to Pointer to the data type you wire to this input. If the data is integer, you can coerce the data to another numeric representation, such as an extended-precision, floating-point number. Pointer: Pointer is a memory address represented by a 32-bit unsigned integer in LabVIEW. Pack Type: Byte alignment information of the Input Type. Output terminals: Value:Value is the data copied from the memory which is pointed by Pointer and changed to the data type specified by Input type.
    1 point
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