Leaderboard

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

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

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.

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

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

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

@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.

Hello everyone, I developed an Addons-Toolkit of LabVIEW, which achieves most of the OpenCV's APIs. It includes more than 2700 VIs, covering 13/15 modules of OpenCV (except flann and gapi) . You can use it to control cameras, process images, run DNN models and so on. Welcome to my CSDN blog to download and give it a try! (Chargeable, 30 days trial) Requirements: Windows 10 or 11, LabVIEW>=2018, 32 or 64 bits.

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. 🙂

There is a "best practices" document (this too) but I suspect you are looking for a less abstract set of guidelines.

@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

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