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Francois Normandin

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Francois Normandin last won the day on March 27

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About Francois Normandin

  • Rank
    Son of Scotland
  • Birthday 02/26/1975

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  • Gender
    Male
  • Location
    Montreal, Canada
  • Interests
    LabVIEW (!!!), Astrophysics, Science-Fiction, Kilts.

LabVIEW Information

  • Version
    LabVIEW 2017
  • Since
    1999

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  1. I don't have a scoop on that, other than they extended the conference by half a day and there will be a public Engineering Impact Award ceremony (whereas before it was a closed event for the nominees only). I don't know if there are more changes to the formula.
  2. Not sure that's the issue, but lags can sometimes occur because the installed code is not compiled for the current version you're using. If you're using VIPM to install the package, make sure your options are set not to prevent compiling after installation. Alternatively, browse to the installed package folder and force it to mass compile. I've seen this behavior for code that installed under Tools menu (under LabVIEW 20xx/project) which were not compiled, so there was always a lag the first time you load it in memory. Being being installed in a non-write accessible folder, it would cause the same issue the next time you'd open LabVIEW and brought the code back into memory.
  3. I agree with James. That could be achieved through composition and adding an abstraction layer. (Sink and Source in the diagram below)
  4. Bonjour Antoine, I'll take a look at this. Can you tell me which version you've installed?
  5. If you need to track frequency in a noisy realtime environment, I've seen Kalman-based filtering being used. Unfortunately, I don't have an implementation example to provide. NI has this discrete filter in the Control Design and Simulation toolkit... which does not come cheap.
  6. It's been moved to another website: http://vfpsoft.com/aes/aes_home.html
  7. The Message Enqueuer instance is created within Actor.vi and encapsulates the receiving queue of the actor. The Actor launcher does not expose any way to specify a more specific type of message enqueuer, so I'm afraid that even though you wish to extend this class, it is impossible to instantiate it with your child type. The reason the Message Enqueuer does not let you access its private data is that it is specifically meant as a wrapper to prevent anyone from accessing the Priority Queue class. I assume the intent is to make sure you cannot mess with the message delivery principles such as rerouting messages before they arrive at the Actor Core. If it were allowed, it could cause thread safety problems, security issues (possible hacking target) or mess with the #1 feature of actors: trust that messages are processed by the core in the order the messages were enqueued.
  8. Hi Diego, to speed things up, you should consider separating the TCP read and the file writing in two separate loops. For example, if you make two parallel loops: one that reads and adds data to a queue, and a second which reads the queue and writes to file, then you can read multiple datapoints at once and write less frequently to the file. Investigate the use of a Producer-Consumer architecture. I took the liberty of reorganizing your example to demonstrate the concept. I'd probably approach your task where your Python code is the client that publishes data and LabVIEW would act as a server (instead of the other way around), but I wanted to keep with the spirit of your example. Client.vi
  9. to the OP: Be mindful that the "Traverse for GObjects" serves the array in the reverse order from Panel:Controls[] method, probably because of the way it stores the references in the recursion loop. @infinitenothing You're totally right. Tab order it is, with newly created controls added at the end of the list.
  10. The method you invoke on the Panel reference always returns the Controls in the order that they were created. aka. If you delete the second element and create a new one (even with same label), it will be added to the end of the list.
  11. Indeed, not a State Machine... "JKI State Machine Objects" gets its name from the use of "JKI State Machine" as its core "Process.vi", which is not a state machine. It is an Event-driven Queued Message Handler (QMH). State Machine was a misnomer and the name stuck around as it was (still is) a very popular template.
  12. The reason for this typecast is to break type propagation that plagues edit-time performance which occur when you have a large class hierarchy. It is not because it makes scripting easier (on the contrary). In essence, when you edit a class' private member, the class' mutation history is modified and the LabVIEW IDE goes through a series of checks and recompiles to propagate the changes. For very small projects, this is completely trivial and does not affect edit-time performance, but for larger hierarchies (think Actor framework...) it becomes a real issue. One way to reduce this performance lag is to never put typedefs in the class private data... but this is up to the developer to stick to that rule or not. When you use an integer, using typedefs does not affect the edit time performances at all. As Rolf mentions, this pattern was popularized by GOOP (now OpenGDS). When creating a framework, you can never predict how the developers will use it... Obviously, if you use a framework and it starts to lag as your project's complexity increases, you are quickly going to blame the framework for the performance degradation (just like we blame Windows for running slower after we've bloated our computers with a bunch of apps, but that's another topic...). So it is very tempting to use tricks like this typecast to an integer to break this slow type propagation. As was mentioned by Smithd, it is risky... but if it stays in the private methods of your class, it is totally safe. In JKI SMO, you'll notice that this is used through two private methods and the DVR type is typedef'ed. You can very well create SMOs that do not use this trick.
  13. Shaun, can you elaborate on why you needed to reinstall the other toolkits when you update your encryption library? If the project-specific librairies all pointed to vi.lib, why did their linkage break?
  14. There are a couple of LabVIEW drivers and example codes on their website. Depending on the positioner model you have, choose the ASCII or Binary version at https://www.zaber.com/zaber-software
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